Flow inside a coral colony measured using magnetic resonance velocimetry


 Benjamin Glenn
 1 years ago
 Views:
Transcription
1 Limnol. Oceanogr., 54(5), 2009, E 2009, by the American Society of Limnology and Oceanography, Inc. Flow inside a coral colony measured using magnetic resonance velocimetry Sandy Chang, a,* Chris Elkins, b Marcus Alley, c John Eaton, b and Stephen Monismith a a Department of Civil and Environmental Engineering, Stanford University, California b Department of Mechanical Engineering, Stanford University, California c Department of Radiology, Stanford University, California Abstract The velocity field within scale models of branching coral Stylophora pistillata colonies was measured using magnetic resonance velocimetry (MRV). The models were based on digital representations of real coral skeletons derived using Xray computed tomography (CT) and constructed using rapidprototype manufacturing. Two morphologies of S. pistillata from the Red Sea grown in different flow regimes were used. To simplify visualization of the data, velocities were parsed into a series of spherical shells, giving the velocity distributions as functions of distance from coral center for both morphologies. The lowflow morphology distributed flow velocity relatively evenly throughout the interior. In contrast, the highflow morphology showed a wider range of velocities with regions of flow channeling and flow stagnation. Corals extract nutrients and particles directly from the water that flows past them at rates determined by the chemistry and hydrodynamics of the fluid adjacent to their surfaces. Engineering correlations for bulk mass transfer indicate that nutrient uptake by the coral is limited by diffusion through the boundary layer (Atkinson and Bilger 1992; Bilger and Atkinson 1992; Atkinson et al. 2001). Because uptake of nutrients by surface chemical reactions is fast compared to transport of species from the bulk fluid to the coral surface (Atkinson 1987), this diffusive boundary layer acts as the main barrier to transport into and out of the organism, and thus is the ratelimiting factor. For a given Schmidt number, Sc 5 n/k, where n is the fluid viscosity, k is the diffusivity of the species of interest (e.g., PO 4 ), and the thickness of the boundary layer is a complex function of the fluid velocity adjacent to the surface as well as the local pressure gradient (Kays and Crawford 1993). Indeed, beyond certain simple cases, e.g., flow over a flat surface with a mild pressure gradient, there are no general rules of thumb connecting diffusive boundary layer thickness and, hence, mass transfer rates, to the bulk flow rates that standard field and laboratory methods can measure. Conventional field and laboratory methods (e.g., acoustic and optical Dopplerbased flowmeters, or particle image velocimetry) can be used to measure flow around the coral colony exterior, but they cannot be used to map flows within the interior, i.e., between the branches. Given that the bulk of the coral surface area is within this interstitial space of the colony, much of the flow dynamics that is important to mass transfer, and hence to coral physiology and ecology, has generally been inaccessible to measurement. This is important because flow variations within this region may be an important determinant to coral morphology (Kaandorp et al. 2003) and may also determine its susceptibility to bleaching (Nakamura and van Woesik 2001). For example, if the flow is channeled through the coral at relatively high velocities along a few preferred flow * Corresponding author: 1819 paths, then mass transfer will vary dramatically throughout the colony surface (Chamberlain and Graus 1975; Kaandorp et al. 2003). To some extent, these variations might be smoothed out by translocation of nutrients and photosynthates (Rinkevich and Loya 1983) and by oscillatory flows (Reidenbach et al. 2006). In contrast, if the flow is mostly stagnant within the colony, then mass transfer in the interior will be sharply reduced relative to the exterior. Most likely, there are both regions of high velocity and of stagnant flow (Chamberlain and Graus 1975). Thus, detailed flow measurements are needed to assess the degree to which the coral colony interior interacts with the exterior environment and thereby participates in mass exchanges needed by the entire colony. Clearly, computing the flow within the colony by directly solving the Navier Stokes equations is viable given the abilities of current highperformance computing platforms and modern computing techniques for dealing with complex geometries (Mittal and Iaccarino 2005). Yet, even such calculations must be compared with measurements to assess their fidelity, given that turbulence is not deterministic and is still ultimately modeled in the simulations. This was the initial motivation for the present work: to provide data that could be used to validate a computational model of the flow through a single coral (Chang 2007). However, it is clear that because of its novelty, such data would be valuable on its own. Computational results for the coral colonies will be presented elsewhere. Here we present direct measurements of the velocity field throughout the entire volume containing a single coral colony of the scleractinian coral Stylophora pistillata with magnetic resonance velocimetry (MRV). This technique measures threecomponent velocity data over the domain of interest without requiring optical or acoustic access for each measurement point. As we discuss below, the unprecedented view of the flow inside a coral colony afforded us by MRV reveals the high degree of spatial variability and complexity that exists there as well as highlighting fundamental differences in flow behavior caused by morphological changes induced by flow.
2 1820 Chang et al. Fig. 1. (a) CT scan for S. pistillata with a conventional scanner. This image is a 2D projection of the final compilation of 245 images taken at every 0.7 mm (in the direction out of the page). The image pixel size is 0.35 mm mm. (b) 3D computerassisted design (CAD) model for lowflow S. pistillata constructed from the CT scan with Mimics TM (Materialise). Methods Overview Scale models of real coral colonies were mounted within a flow channel which was placed within a clinical magnetic resonance imaging (MRI) scanner to measure the full threedimensional (3D) velocity field around and within the coral colony. While a powerful tool, the use of MRI to measure flows places several significant constraints on any experiment: (1) the flow channel cannot contain any ferrous materials, and it must be small enough to fit within a coil that can provide high resolution data; (2) since the MRI unit s primary function is medical diagnosis, access time is limited; and (3) measuring a single 3D flow field is time consuming in our case approximately 3 h. Taken together, these constraints meant that there were significant limits to the number of cases that could be run. Coral models Rather than use idealizations of coral colonies, real coral geometries were used in the experiments. However, given that the real corals of interest were larger than the channel that would fit within the MRI coil used, digital representations of the corals were obtained so that scale models could be constructed. Two coral morphologies of S. pistillata from highflow (u mean 5 7cms 21 ) and lowflow (u mean 5 4cms 21 ) environments were chosen for the experiments. These particular coral colonies, which were from the Red Sea near Eilat and which were also used by Reidenbach et al. (2006) in their experiments, have distinctly different morphologies: The lowflow morphology (LFM) has finer branches that tend to extend further out from the center, compared with the highflow morphology (HFM) which has more compact, thicker branches. The 3D images of these coral skeletons were obtained using Xray computed tomography (CT). CT can effectively image calcium carbonate, the basis for both bone and coral skeleton (Kaandorp et al. 2003; Chang 2007). For the LFM, a standard CT scanner was used with a resolution of 0.35 mm inplane and 0.7 mm outofplane, resulting in 245 images. Figure 1a shows the twodimensional (2D) projection of the CT scan for this coral. For the HFM, the Axiom Artis dta angiography suite (Siemens), capable of creating isotropic volume pixels, or voxels, was used. This scan resulted in 290 slices with mm voxel resolution. Using the CT data set, 3D solid models were constructed for both morphologies using the commercial software Mimics TM (Materialise) (Fig. 1b). This computeraided design (CAD) model was exported to a stereolithography (stl) file for rapid protoype (RP) manufacturing. The coral models were built at the University of Texas El Paso by Dr. Ryan Wicker using acrylonitrile butadiene styrene (ABS) plastic with a fuseddeposition modeling (FDM) Maxum System (Stratasys). The LFM and HFM models were scaled by factors of 75% and 90% relative to their parents, respectively. The streamwise (x), crossstream (y), and vertical (z) extents of the LFM were 9.3 cm, 10.7 cm, and 9.8 cm, respectively. The streamwise (x), crossstream (y), and vertical (z) extents of the HFM were 12.8 cm, 13.2 cm, and 9.0 cm, respectively. Because of the resolution of the CT scans and the prototype manufacturing, the small roughness scale of the coral surface (e.g., corallite) was smoothed out. While this may affect the finescale fluid dynamics, the turbulence is primarily created by largescale roughness, as defined by the branches (Hearn et al. 2001). Experiments We used the MRV technique described by Markl et al. (2003), which is based on a 3D, phasecontrast imaging sequence, to measure all three velocity components. This method provided accurate meanvelocity measurements in turbulent flows when results were averaged over repeated scans (Elkins et al. 2004; Elkins and Alley 2007). All experiments were performed using a 1.5T clinical magnetic resonance (MR) system [GE Signa CV/I (cardiovascular imaging system)], with a singlechannel receiver coil designed for human heads. A channel 19 cm wide 3 17 cm tall by 85 cm long was built to fit into this coil (Fig. 2a). A schematic of the flow loop is shown in Fig. 2b. A centrifugal
3 Flow inside a coral colony 1821 pump circulated water at a flow rate of 77 L min 21.A gadoliniumbased contrast agent was added to the water to enhance signal intensity and facilitate imaging. A 57cmlong diffuser section connected the 5.1cmdiameter inlet to the 17cm 3 19cm testchannel cross section. Three screens with differential grid spacing (with lowest void ratio in the center and increasing outward) were installed along the cm length of the diffuser to spread out the flow and to create a more uniform velocity profile at the inlet to the rectangular channel test section. The center of the coral was mounted 35 cm downstream of the inlet. The bulk mean velocity in the test channel was approximately 5 cm s 21, giving a Reynolds number (Re 5 UL/n, where U is the average velocity, L is the lengthscale, and n is the kinematic viscosity) of approximately 5000, based on the height of the coral. While this may be the most appropriate length scale for flow structures resulting from the coral in its entirety, branch diameter may be a more appropriate length scale for the interior flow, because individual branches significantly contribute to flow variations in this region. In this case, we estimated Re for the LFM and Re for the HFM based on diameters for the circular approximation of the branch s cross sections. The experimental velocity of 5cms 21 was chosen for both morphologies in order to isolate the coral geometry as the only variable. The imaging volume consisted of mmthick slices each with a 28cm, inplane fieldofview (FOV) extending from approximately 0.5 colony diameters upstream and 1 diameter downstream from the front and back edges of the coral, respectively. The inplane resolution in each direction was 1.09 mm, thus defining a 3D voxel approximately 1 mm on each side. Error estimation for MRV depended on the signaltonoise ratio and the encoding velocity used for the phase contrast measurements (Elkins and Alley 2007). In this experiment, the estimate for the uncertainty in velocity was approximately 0.5 cm s 21. Results Fig. 2. (a) Water channel constructed for the MRV experiment. (b) Schematic of the water flow loop in the MRI scanner. The CT scans allowed us to quantify several simple morphological differences between the two corals (Table 1). Note that more sophisticated descriptions of the morphology are possible (Kaandorp and Kübler 2001), but are likely to be less relevant for describing flow structure differences than they are for documenting morphological complexity and self similarity. We computed the ratio of volume to surface area, an effective branch thickness scale, finding that the HFM branches were approximately 1/3 thicker than those of the LFM. We also computed the ratio of the frontal area, defined by the coral outline, to surface area; as expected, the HFM has significantly more surface area per area facing into the flow. Likewise, a, the ratio of total surface area to planar projected area (Bilger and Atkinson 1992; Falter et al. 2005) was larger for the HFM than for the LFM. Thus in principal, these two measurements suggest that, all else being equal, the HFM should support a higher overall mass flux to the colony. However, as the MRV measurements demonstrated, the HFM in general experienced lower velocities in the interior, which tended to increase the boundarylayer thickness and consequently reduced mass transfer. Finally, the ratio of branch distance to branch radius (which we measured by Table 1. Physical and morphological properties of Low flow (LFM) and High flow (HFM) morphologies of S. pistillata. Low flow High flow u mean (cm s 21 ) 4 7 Ratio of volume to surface area (cm) Ratio of surface area to planar projected area (a) Ratio of frontal area to surface area Ratio of branch distance to branch radius
4 Flow inside a coral colony 1823 enclosed the coral. Average streamwise velocities were calculated in shells of 5mm thickness at various radial fractions (Fig. 5a). We explored these trends by using different shell sizes and found the same results for shells of different thicknesses; the trends seen in Fig. 5a were therefore not dependent on the choice of shell size. To extend this analysis, the fraction of coral surface area contained in each shell was calculated and plotted with radial distance from the coral center (Fig. 5b). Finally, the normalized mean velocity of the shell was plotted versus the fraction of coral surface area in the shell to show the distribution of mean velocity over the coral surface (Fig. 5c). A small subset of the entire 3D data set is presented in Fig. 6 as sequences of 2D contour plots in planes with different orientations. These contour plots were useful for visualizing the flow around and through each of the coral geometries as well as comparing the flow patterns between the two corals. Figure 6 shows contour plots of the velocity magnitude (m s 21 ) in multiple planes close to the center of the two corals with the coral shown as white. Columns (a) and (b) show planes normal to the y direction for LFM and HFM, respectively. Columns (c) and (d) show planes normal to the z direction for LFM and HFM, respectively. The middle row [row (3)] was the middle of the coral, and each slice was shifted 5 mm from its neighbors. Flow was in the positive x direction. Upon inspecting Fig. 6, one would expect velocities to vary not only with radial distance from the center but also with location relative to the incoming flow. In Fig. 7, velocity data are analyzed spatially by dividing the spherical shells of Fig. 5 into four quadrants relative to the incoming flow: upper front, lower front, upper back, and lower back. The normalized average velocity was plotted as a function of normalized radius, or radial fraction, in these regions for both coral geometries. Discussion The vector field in Fig. 3 shows how the flow is diverted laterally outward, around, and vertically up and over the coral on the upstream side like a baffle, as suggested by earlier flow visualization studies (Chamberlain and Graus 1975; Reidenbach et al. 2006). The flow slowed and recirculated behind the coral colony as a whole as well as behind individual branches. Thus, parcels of water along with what they carry were trapped with longer residence times behind each coral branch than in the passages between them. Moreover, this behavior would imply a muchreduced access to particulate fluxes (e.g., zooplankton) in the lee of each branch than on the forward sides, and for the interior and back of the colony relative to the front, sides, and top of it. This was further exacerbated by the recirculation, which circulated nutrientdepleted water behind each branch. As seen in Fig. 3, flow blockage, channeling, and recirculation are evident throughout the interior, resulting in large spatial variability in the velocity distribution. Where one branch was in front of another, the upstream branch created a wake that significantly reduced the Fig. 5. (a) Normalized average streamwise velocity in the interior as a function of radial distance by fraction of total radius for both low and highflow morphologies. (b) Surface area of coral in each shell. (c) Distribution of normalized mean velocities over the fraction of coral surface area as extracted from shell analysis.
5 1824 Chang et al. Fig. 6. Column (a) yplane slices for lowflow morphology. (b) yplane slices for highflow morphology. (c) zplane slices for lowflow morphology. (d) zplane slices for highflow morphology. The middle row [row (3)] is the middle of the coral, and each slice is shifted 5 mm from its neighbors. Flow is in the positive x direction. The colors specify velocity in m s 21. downstream velocity. To the extent that mass transfer was related to local velocity shear, the nearsurface velocities shown in Fig. 4 suggest that there should have been much higher local mass transfer in some regions, e.g., forwardfacing branch tips. As expected, the upstream side of the coral was exposed to higher velocity than the downstreamfacing side. However, the figure shows local highs on the tips of many branches, regardless of their orientation or location throughout the coral, which may indicate the relative importance of the tips to mass transfer, i.e., nutrient acquisition or waste metabolite removal, relative to the rest of the coral. The mean streamlines in Fig. 4 serve to illustrate the effects of the coral on the surrounding fluid, showing that flow passing through the periphery and toward the outer edge of the coral retains its high velocity and relatively straight trajectory. In contrast, flow in the center and especially near the bottom of the coral tended to meander and slow down significantly. Thus, the overall distribution of velocities as a function of position in the colony varied significantly. Additionally, the mean streamlines show that the extent of the overall wake behind the coral colony extended more than one colony diameter downstream from the back edge of the coral. Consequently, for densely spaced colonies, the incoming flow would be strongly affected by distance to its upstream neighbor. One effect of the flow diversion by the colony was to reduce the overall supply of material from upstream into the colony. To quantify this reduction, we determined the overall shadow or outline of the coral and then computed the flow through every streamwise slice in the scanned domain. Because the slices at the upstream and downstream edges of the scans tended to have low signaltonoise ratio, those slices were removed from the analysis. The flow that penetrated through the coral interior normalized by the oncoming flow through the coral outline was plotted for both morphologies in Fig. 8. In both cases, the flow that penetrated the interior decreased progressively along the streamwise direction, reaching 35% and 23% of the incoming flow for the LFM and the HFM, respectively. Equivalently, the flow that was diverted by the coral increased progressively in the streamwise direction. The stark difference between the two morphologies is due to the fact that the LFM allowed more flow penetration through its sparser branches. Additionally, because the branches also spread out further (see Table 1), the coral outline defined for the LFM had more voids and thus resulted in a higher fraction of the upstream flow penetrating into the coral interior. In contrast, the HFM was much denser and presented higher resistance to flow, thus resulting in more flow diverted around the colony. Moreover, the flow through the colony decreased more rapidly through the colony for the HFM as compared with the LFM, with approximately 80% of the flow diverted in the former case, as compared to 60% in the latter. A notable difference between the two morphologies was the velocity rebound in the wake, where the LFM velocity increased slightly from 35% to 40%. In
6 Flow inside a coral colony 1825 Fig. 7. Normalized average velocities calculated for spherical shells with 5mm radial thickness are plotted as a function of normalized radius from the coral centers for four spatial quadrants oriented relative to the streamwise direction: upper front (x solid), lower front (circle solid), upper back (x dashed), and lower back (circle dashed). (a) lowflow morphology and (b) highflow morphology. contrast, the HFM had a much greater rebound, from 23% to 42%. It is wellknown that flows around surface mounted obstacles are accompanied by vortices such as the horseshoe vortex that can wrap around the object, forming streamwise vortices downstream (Mason and Morton 1987). Thus the difference in wake dynamics may be associated with differences in the vortex system around the two corals. Nonetheless, these wake observations imply that the influence of an LFM colony may extend farther downstream than would that of an HFM colony, thus having a greater effect at a fixed distance on mass fluxes for its neighbors downstream. The differences in the average velocity of the spherical shell between the interior (0 70% from coral center) and exterior (70 100% from coral center) for the two morphologies were not dramatic (Fig. 5), with the lowest interior Fig. 8. Fraction of incoming flow penetrating into coral interior and subsequent wake of coral imprint for (a) lowflow morphology and (b) highflow morphology. The vertical lines denote the front and rear edges of the coral. velocity being 59% of the bulk velocity for the LFM and 48% for the HFM. These differences are comparable to the masstransfer rate differences between exterior and interior of corals measured by Reidenbach et al. (2006), where gypsum dissolution was used as a proxy for relative velocity measurements. Our data indicate that on average, the LFM with its more intricate and finer branching pattern as compared to the HFM distributed flow speed evenly throughout the interior, where a relatively constant mean velocity existed between 20% and 70% of the radius. In contrast, the HFM, with its thicker branches, tended to channel the flow in the manner described in Chamberlain and Graus (1975), leading to greater variability in the interior flow, as seen in the troughs at 0.3 radial fractions and 0.6 radial fractions in the HFM (Fig. 5). Both corals shared the same distribution of surface area, with the peak surface area occurring at a radius that was 70% of the maximum. Interestingly, this same position separated the nearly constant portion of the velocity curve
7 1826 Chang et al. seen in the interior of the coral from the increasing velocity curve for greater radii. This indicates a clear demarcation between the interior versus exterior hydrodynamic partitions, where the interior is the region where the hydrodynamics is manipulated by the coral, and the exterior is the region where the hydrodynamics is determined by the bulk velocity. While data points were scattered, the highest flow speed was consistently experienced by the outermost shells, as expected. The difference between the interior flow behaviors of the LFM and HFM colonies was qualitatively apparent in the crosssectional slices shown in Fig. 6 as well. The slices for the LFM (columns a and c) show that there was more open space in the interior between the more sparsely distributed branches of this colony as compared with the HFM (columns b and d). Consequently, the flow tended to be more evenly distributed throughout the interior, as evidenced by the similar velocities. In contrast, the HFM slices show more coral mass. This resulted in significant flow retardation in the lee of many branches. In addition, highvelocity channels are sometimes created by favorable branch alignment when two or more branches lie directly behind one another. One cautionary note is that the observed highvelocity channels may be a function of the way the coral was oriented with respect to the streamwise direction in our experiments which may have been different from the actual orientation of the coral relative to the dominant flow direction where it grew. However, while the location of these channels depends on the orientation in the flow, it seems likely that with a different orientation, similar channels would appear, just in other regions. Therefore, the net effect of channeling should be relatively independent of flow direction. Using the plots in Fig. 6 as a guide, the LFM appears to have distributed the flow relatively uniformly throughout the interior. This allowed the interior of the colony to more actively participate in mass transfer and particle capture. The HFM, in contrast, created larger lowvelocity separation zones behind its bigger branches as well as several long, highvelocity channels as an alternative way for the flow to pass through the interior. This may indicate high variation in mass transfer, thus nutrient uptake, as a function of location on the coral surface. It is obvious from the contour plots in Fig. 6 that velocities varied throughout the interior of the coral. The plots in Fig. 8 parse the shell velocity data shown in Fig. 6 into four spatial quadrants relative to the incoming flow: upper front, lower front, upper back, and lower back. The plots show that the front experienced higher velocity than the back. An exception was in the smallest shells in the interior of the coral, where the flow was more tied to the local coral geometry than to the bulk. The velocities of smallest shells in all quadrants were similar despite the significant differences in the velocities of the largest shells. Additionally, the front faces of both morphologies seem to have experienced similar conditions, starting with middle to high velocities (normalized by the bulk mean velocity) in the center which gradually increased as the shells moved outward from the interior (solid lines in Fig. 8). This was not the case for the back faces, where the bottom quadrant consistently experienced lower velocities. This was consistent with the visualizations of the MRV volume (Figs. 5, 7), where wake effects were strongest at the base of the coral with lower velocities and recirculation. Both corals showed strikingly similar trends for all four quadrants. One major difference was that HFM had lower velocity in its top and, especially, bottom back regions, most likely due to its thicker base, trunk, and branches. It is important to remember that the distribution of flow through the coral interior is highly dependent on the upstream flow characteristics. In a canopy environment, where one coral sits in the wake of another coral upstream, the velocity distribution will likely differ from the results shown here. The picture that emerged from these observations is one that suggests extreme variability in mass transfer throughout the colony. Moreover, these variations should be more pronounced from the front to the back of the colony given that mass fluxes also depend on the spatially developing concentration field. If there is high mass transfer at the front of the colony, there will be lower nutrient concentrations at the back, leading to lower mass transfer rates near the back than would be expected based on difference in velocity shear. Thus, one can hypothesize that the low mass transfer portion of the colony must rely on high mass transfer regions to help support the total transfer of materials into and out of the colony, using mechanisms like translocation as described by Rinkevich and Loya (1983). Nonetheless, as shown by Mass and Genin (2008), in unidirectional flows, significant fronttoback asymmetry in distribution of zooxanthellae and eventually in skeleton mass can develop, and therefore there must be limits to the utility of translocation to smooth out spatial variations in mass transfer. On the other hand, in their natural habitat, the corals Mass and Genin studied experienced bidirectional tidal flows and so remained approximately symmetric. Overall, because of the complexity of the coral geometry, it is clear that simple models like periodic arrays of tubes (Eckman 1983), rods (Nepf and Vinoni 2000), or cylinders (Lowe et al. 2005) only bear a very coarse similarity to the flow inside a single coral colony, i.e., all these structural arrangements led to flow channeling and sheltering, as well as to flow diversion around and above the structures. Additionally, the strong effects of the wakes of upstream branches on the flow incident to downstream branches mean that it may be difficult to extrapolate the results of studies with single branches to colonylevel fluxes (Sebens et al. 1997) unless the branches are very sparse. More importantly, there is an important difference in scale between our work and that of the studied periodic arrays. Our study focused on flows inside a single structure as opposed to considering a collection of such structures assembled into a canopy (Lowe et al. 2008). When describing flows through and over biological canopies (reefs, polychaete tube arrays, and seagrass beds), the focus is usually on spatially averaged processes such as net momentum or mass transfer, whereas the MRV measurements we present here show details inside one element of what might compose such a canopy. The classical view of a canopy also assumes some spatially statistical homogene
8 Flow inside a coral colony 1827 ity, whereas here we emphasize the complete absence of any such homogeneity, i.e., that single colonies have notable channels and dead zones with very different shears and speeds, and thus, presumably, very different local rates of mass transfer and particle capture throughout their surfaces. Detailed threecomponent mean velocity distributions inside two coralcolony interiors were measured using MRV. This noninvasive technique captured not only the effects of the colony as a whole on the flow, but also of the individual branches, which produced wakes that influenced flows around downstream branches. Additionally, two different characteristics for interior flow were identified: the relatively even distribution of flow in the case of the LFM, as opposed to the defined channeling of the HFM. These differences in flow behavior may reflect the way coral colony morphologies adapt to their natural flow environments. These measurements emphasized the high intracolony variability of the potential for mass transfer, behavior that should be accounted for in any model connecting coral morphology and physiology to flow. Acknowledgements The authors would like to express their gratitude to Amatzia Genin of Steinitz Marine Laboratory for generously providing the coral skeletons and indispensable guidance on coral biology, to Ryan Wicker and Frank Medina of the University of Texas at El Paso for providing the models, to Robert Bennett for assistance on the computed tomography, to Michael Markl for initial magnetic resonance scanning, to Lars Saetran of Norwegian University of Science and Technology for help with the magnetic resonance velocimetry experiments, and to Jeff Koseff and Jonah Steinbuck of Stanford University for helpful discussions. We would also like to acknowledge the reviewers for their valuable input. This research was supported by the National Science Foundation grant OCE References ATKINSON, M Rates of phosphate uptake by coral reef communities. Limnol. Oceanogr. 32: , AND R. BILGER Effects of water velocity on phosphate uptake in coral reefflat communities. Limnol. Oceanogr. 37: , J. FALTER, AND C. HEARN Nutrient dynamics in the Biosphere 2 coral reef mesocosm: water velocity controls NH 4 and PO 4 uptake. Coral Reefs 20: BILGER, R., AND M. ATKINSON Anomalous mass transfer of phosphate on coral reef flats. Limnol. Oceanogr. 37: CHAMBERLAIN, J., AND R. GRAUS Water flow and hydromechanical adaptations of branched reef corals. Bull. Mar. Sci. 25: CHANG, S Smallscale flow variability inside branched coral colonies: Computations and experimental validation. Ph.D. thesis. Stanford Univ. ECKMAN, J. E Hydrodynamic processes affecting benthic recruitment. Limnol. Oceanogr. 28: ELKINS, C. J., AND M. T. ALLEY Magnetic resonance velocimetry: Applications of magnetic resonance imaging in the measurement of fluid motion. Exp. Fluids 43: , M. MARKL, A. IYENGAR, R. WICKER, AND J. K. EATON Fullfield velocity and temperature measurements using magnetic resonance imaging in turbulent complex internal flows. Int. J. Heat Fluid Flow 25: FALTER, J. L., M. J. ATKINSON, AND C. F. M. COIMBRA Effects of surface roughness and oscillatory flow on the dissolution of plaster forms: Evidence of nutrient mass transfer to coral reef communities. Limnol. Oceanogr. 50: HEARN, C. J., M. J. ATKINSON, AND J. L. FALTER A physical derivation of nutrientuptake rates in coral reefs: Effects of roughness and waves. Coral Reefs 20: KAANDORP, J. A., E. A. KOOPMAN, P. M. A. SLOOT, R. P. M. BAK, M. J. A. VERMEIJ, AND L. E. H. LAMPMANN Simulation and analysis of flow patterns around the scleractinian coral Madracis mirabilis (Duchassaing and Michelotti). Phil. Trans. R. Soc. Lond. B. 358: , AND J. E. KÜBLER The algorithmic beauty of seaweeds, sponges, and corals. Springer Verlag. KAYS, W. M., AND M. E. CRAWFORD Convective heat and mass transfer, 3rd ed. McGrawHill. LOWE, R. J., J. R. KOSEFF, AND S. G. MONISMITH Oscillatory flow through submerged canopies. Part 1. Velocity structure. J. Geophys. Res. 110: C10016, doi: /2004jc , U. SHAVIT, J. L. FALTER, J. R. KOSEFF, AND S. G. MONISMITH Modeling flow in coral communities with and without waves: A synthesis of porous media and canopy flow approaches. Limnol. Oceanogr. 53: MARKL, M., AND others Time resolved three dimensional phase contrast MRI 4Dflow. J. Magn. Reson. Imaging 17: MASON, P. J., AND B. R. MORTON Trailing vortices in the wakes of surfacemounted obstacles. J. Fluid Mech. 175: MASS, T., AND A. GENIN Environmental versus intrinsic determination of colony symmetry in the coral Pocillopora verrucosa. Mar. Ecol. Prog. Ser. 369: MITTAL, R., AND G. IACCARINO Immersed boundary method. Ann. Rev. Fluid Mech. 37: NAKAMURA, T., AND R. VAN WOESIK Waterflow rates and passive diffusion partially explain differential survival of corals during the 1998 bleaching event. Mar. Ecol. Prog. Ser. 212: NEPF, H. M., AND E. R. VIVONI Flow structure in depthlimited, vegetated flow. J. Geophys. Res. 105: REIDENBACH, M., J. KOSEFF, S. MONISMITH, J. STEINBUCK, AND A. GENIN The effects of waves and morphology on mass transfer within branched reef corals. Limnol. Oceanogr. 51: RINKEVICH, B., AND Y. LOYA Oriented translocation of energy in grafted reef corals. Coral Reefs 1: SEBENS, K. P., J. WITTING, AND B. HELMUTH Effects of water flow and branch spacing on particle capture by the reef coral Madracis mirabilis (Duchassaing and Michelotti). J. Exp. Mar. Bio. Ecol. 211: Associate editor: Christopher M. Finelli Received: 31 July 2008 Accepted: 21 April 2009 Amended: 05 May 2009
HEAT TRANSFER ANALYSIS IN A 3D SQUARE CHANNEL LAMINAR FLOW WITH USING BAFFLES 1 Vikram Bishnoi
HEAT TRANSFER ANALYSIS IN A 3D SQUARE CHANNEL LAMINAR FLOW WITH USING BAFFLES 1 Vikram Bishnoi 2 Rajesh Dudi 1 Scholar and 2 Assistant Professor,Department of Mechanical Engineering, OITM, Hisar (Haryana)
More informationNUMERICAL STUDY OF FLOW AND TURBULENCE THROUGH SUBMERGED VEGETATION
NUMERICAL STUDY OF FLOW AND TURBULENCE THROUGH SUBMERGED VEGETATION HYUNG SUK KIM (1), MOONHYEONG PARK (2), MOHAMED NABI (3) & ICHIRO KIMURA (4) (1) Korea Institute of Civil Engineering and Building Technology,
More informationUsing CFD to improve the design of a circulating water channel
27 December 27 Using CFD to improve the design of a circulating water channel M.G. Pullinger and J.E. Sargison School of Engineering University of Tasmania, Hobart, TAS, 71 AUSTRALIA Abstract Computational
More informationAbaqus/CFD Sample Problems. Abaqus 6.10
Abaqus/CFD Sample Problems Abaqus 6.10 Contents 1. Oscillatory Laminar Plane Poiseuille Flow 2. Flow in Shear Driven Cavities 3. Buoyancy Driven Flow in Cavities 4. Turbulent Flow in a Rectangular Channel
More informationDifferential Relations for Fluid Flow. Acceleration field of a fluid. The differential equation of mass conservation
Differential Relations for Fluid Flow In this approach, we apply our four basic conservation laws to an infinitesimally small control volume. The differential approach provides point by point details of
More informationDimensional Analysis
Dimensional Analysis An Important Example from Fluid Mechanics: Viscous Shear Forces V d t / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / Ƭ = F/A = μ V/d More generally, the viscous
More informationPractice Problems on Boundary Layers. Answer(s): D = 107 N D = 152 N. C. Wassgren, Purdue University Page 1 of 17 Last Updated: 2010 Nov 22
BL_01 A thin flat plate 55 by 110 cm is immersed in a 6 m/s stream of SAE 10 oil at 20 C. Compute the total skin friction drag if the stream is parallel to (a) the long side and (b) the short side. D =
More informationExpress Introductory Training in ANSYS Fluent Lecture 1 Introduction to the CFD Methodology
Express Introductory Training in ANSYS Fluent Lecture 1 Introduction to the CFD Methodology Dimitrios Sofialidis Technical Manager, SimTec Ltd. Mechanical Engineer, PhD PRACE Autumn School 2013  Industry
More informationNUMERICAL ANALYSIS OF THE EFFECTS OF WIND ON BUILDING STRUCTURES
Vol. XX 2012 No. 4 28 34 J. ŠIMIČEK O. HUBOVÁ NUMERICAL ANALYSIS OF THE EFFECTS OF WIND ON BUILDING STRUCTURES Jozef ŠIMIČEK email: jozef.simicek@stuba.sk Research field: Statics and Dynamics Fluids mechanics
More information(1) 2 TEST SETUP. Table 1 Summary of models used for calculating roughness parameters Model Published z 0 / H d/h
Estimation of Surface Roughness using CFD Simulation Daniel Abdi a, Girma T. Bitsuamlak b a Research Assistant, Department of Civil and Environmental Engineering, FIU, Miami, FL, USA, dabdi001@fiu.edu
More information5 Factors Affecting the SignaltoNoise Ratio
5 Factors Affecting the SignaltoNoise Ratio 29 5 Factors Affecting the SignaltoNoise Ratio In the preceding chapters we have learned how an MR signal is generated and how the collected signal is processed
More informationAN EFFECT OF GRID QUALITY ON THE RESULTS OF NUMERICAL SIMULATIONS OF THE FLUID FLOW FIELD IN AN AGITATED VESSEL
14 th European Conference on Mixing Warszawa, 1013 September 2012 AN EFFECT OF GRID QUALITY ON THE RESULTS OF NUMERICAL SIMULATIONS OF THE FLUID FLOW FIELD IN AN AGITATED VESSEL Joanna Karcz, Lukasz Kacperski
More informationUniversity Turbine Systems Research 2012 Fellowship Program Final Report. Prepared for: General Electric Company
University Turbine Systems Research 2012 Fellowship Program Final Report Prepared for: General Electric Company Gas Turbine Aerodynamics Marion Building 300 Garlington Rd Greenville, SC 29615, USA Prepared
More informationSteady Heat Conduction
Steady Heat Conduction In thermodynamics, we considered the amount of heat transfer as a system undergoes a process from one equilibrium state to another. hermodynamics gives no indication of how long
More informationInternational Year of Light 2015 TechTalks BREGENZ: Mehmet Arik WellBeing in Office Applications Light Measurement & Quality Parameters
www.ledprofessional.com ISSN 1993890X Trends & Technologies for Future Lighting Solutions ReviewJan/Feb 2015 Issue LpR 47 International Year of Light 2015 TechTalks BREGENZ: Mehmet Arik WellBeing in
More informationLecture 6  Boundary Conditions. Applied Computational Fluid Dynamics
Lecture 6  Boundary Conditions Applied Computational Fluid Dynamics Instructor: André Bakker http://www.bakker.org André Bakker (20022006) Fluent Inc. (2002) 1 Outline Overview. Inlet and outlet boundaries.
More informationA LAMINAR FLOW ELEMENT WITH A LINEAR PRESSURE DROP VERSUS VOLUMETRIC FLOW. 1998 ASME Fluids Engineering Division Summer Meeting
TELEDYNE HASTINGS TECHNICAL PAPERS INSTRUMENTS A LAMINAR FLOW ELEMENT WITH A LINEAR PRESSURE DROP VERSUS VOLUMETRIC FLOW Proceedings of FEDSM 98: June 5, 998, Washington, DC FEDSM98 49 ABSTRACT The pressure
More informationAdaptation of General Purpose CFD Code for Fusion MHD Applications*
Adaptation of General Purpose CFD Code for Fusion MHD Applications* Andrei Khodak Princeton Plasma Physics Laboratory P.O. Box 451 Princeton, NJ, 08540 USA akhodak@pppl.gov Abstract Analysis of many fusion
More informationFluent Software Training TRN Boundary Conditions. Fluent Inc. 2/20/01
Boundary Conditions C1 Overview Inlet and Outlet Boundaries Velocity Outline Profiles Turbulence Parameters Pressure Boundaries and others... Wall, Symmetry, Periodic and Axis Boundaries Internal Cell
More informationEXPERIMENTAL AND NUMERICAL ANALYSIS OF THE COLLAR PRODUCTION ON THE PIERCED FLAT SHEET METAL USING LASER FORMING PROCESS
JOURNAL OF CURRENT RESEARCH IN SCIENCE (ISSN 23225009) CODEN (USA): JCRSDJ 2014, Vol. 2, No. 2, pp:277284 Available at www.jcrs010.com ORIGINAL ARTICLE EXPERIMENTAL AND NUMERICAL ANALYSIS OF THE COLLAR
More informationOptical Design Tools for Backlight Displays
Optical Design Tools for Backlight Displays Introduction Backlights are used for compact, portable, electronic devices with flat panel Liquid Crystal Displays (LCDs) that require illumination from behind.
More informationGLOBAL MANUFACTURING. ARAUJO, Anna Carla AUG, 2015 Mechanical Engineering Department POLI/COPPE/UFRJ
GLOBAL MANUFACTURING ARAUJO, Anna Carla AUG, 2015 Mechanical Engineering Department POLI/COPPE/UFRJ Workpiece Presentation Powder Metallurgy and Additive Manufacturing [#7] Powder Metallurgy PM parts can
More informationComparison of CFD models for multiphase flow evolution in bridge scour processes
Comparison of CFD models for multiphase flow evolution in bridge scour processes A. BayónBarrachina, D. Valero, F.J. Vallès Morán, P. A. LópezJiménez Dept. of Hydraulic and Environmental Engineering
More informationME6130 An introduction to CFD 11
ME6130 An introduction to CFD 11 What is CFD? Computational fluid dynamics (CFD) is the science of predicting fluid flow, heat and mass transfer, chemical reactions, and related phenomena by solving numerically
More informationXI / PHYSICS FLUIDS IN MOTION 11/PA
Viscosity It is the property of a liquid due to which it flows in the form of layers and each layer opposes the motion of its adjacent layer. Cause of viscosity Consider two neighboring liquid layers A
More informationNatural Convection. Buoyancy force
Natural Convection In natural convection, the fluid motion occurs by natural means such as buoyancy. Since the fluid velocity associated with natural convection is relatively low, the heat transfer coefficient
More informationPlate waves in phononic crystals slabs
Acoustics 8 Paris Plate waves in phononic crystals slabs J.J. Chen and B. Bonello CNRS and Paris VI University, INSP  14 rue de Lourmel, 7515 Paris, France chen99nju@gmail.com 41 Acoustics 8 Paris We
More informationChapter 2. Derivation of the Equations of Open Channel Flow. 2.1 General Considerations
Chapter 2. Derivation of the Equations of Open Channel Flow 2.1 General Considerations Of interest is water flowing in a channel with a free surface, which is usually referred to as open channel flow.
More informationOPTIMISE TANK DESIGN USING CFD. Lisa Brown. Parsons Brinckerhoff
OPTIMISE TANK DESIGN USING CFD Paper Presented by: Lisa Brown Authors: Lisa Brown, General Manager, Franz Jacobsen, Senior Water Engineer, Parsons Brinckerhoff 72 nd Annual Water Industry Engineers and
More informationCollision of a small bubble with a large falling particle
EPJ Web of Conferences 67, 212 (214) DOI: 1.11/ epjconf/ 21467212 C Owned by the authors, published by EDP Sciences, 214 Collision of a small bubble with a large falling particle Jiri Vejrazka 1,a, Martin
More informationIntegration of a fin experiment into the undergraduate heat transfer laboratory
Integration of a fin experiment into the undergraduate heat transfer laboratory H. I. AbuMulaweh Mechanical Engineering Department, Purdue University at Fort Wayne, Fort Wayne, IN 46805, USA Email: mulaweh@engr.ipfw.edu
More informationAN INVESTIGATION INTO THE USEFULNESS OF THE ISOCS MATHEMATICAL EFFICIENCY CALIBRATION FOR LARGE RECTANGULAR 3 x5 x16 NAI DETECTORS
AN INVESTIGATION INTO THE USEFULNESS OF THE ISOCS MATHEMATICAL EFFICIENCY CALIBRATION FOR LARGE RECTANGULAR 3 x5 x16 NAI DETECTORS Frazier L. Bronson CHP Canberra Industries, Inc. 800 Research Parkway,
More informationLecture 11 Boundary Layers and Separation. Applied Computational Fluid Dynamics
Lecture 11 Boundary Layers and Separation Applied Computational Fluid Dynamics Instructor: André Bakker http://www.bakker.org André Bakker (20022006) Fluent Inc. (2002) 1 Overview Drag. The boundarylayer
More informationA subgridscale model for the scalar dissipation rate in nonpremixed combustion
Center for Turbulence Research Proceedings of the Summer Program 1998 11 A subgridscale model for the scalar dissipation rate in nonpremixed combustion By A. W. Cook 1 AND W. K. Bushe A subgridscale
More informationHigh resolution modelling of flowvegetation interactions: From the stem scale to the reach scale
Septième École Interdisciplinaire de Rennes sur les Systèmes Complexes  13 th October 2015 High resolution modelling of flowvegetation interactions: From the stem scale to the reach scale Tim Marjoribanks
More informationBasic Equations, Boundary Conditions and Dimensionless Parameters
Chapter 2 Basic Equations, Boundary Conditions and Dimensionless Parameters In the foregoing chapter, many basic concepts related to the present investigation and the associated literature survey were
More informationKeywords: Heat transfer enhancement; staggered arrangement; Triangular Prism, Reynolds Number. 1. Introduction
Heat transfer augmentation in rectangular channel using four triangular prisms arrange in staggered manner Manoj Kumar 1, Sunil Dhingra 2, Gurjeet Singh 3 1 Student, 2,3 Assistant Professor 1.2 Department
More informationEffects of mass transfer processes in designing a heterogeneous catalytic reactor
Project Report 2013 MVK160 Heat and Mass Transport May 13, 2013, Lund, Sweden Effects of mass transfer processes in designing a heterogeneous catalytic reactor Maryneth de Roxas Dept. of Energy Sciences,
More informationHead Loss in Pipe Flow ME 123: Mechanical Engineering Laboratory II: Fluids
Head Loss in Pipe Flow ME 123: Mechanical Engineering Laboratory II: Fluids Dr. J. M. Meyers Dr. D. G. Fletcher Dr. Y. Dubief 1. Introduction Last lab you investigated flow loss in a pipe due to the roughness
More informationChapter 10. Flow Rate. Flow Rate. Flow Measurements. The velocity of the flow is described at any
Chapter 10 Flow Measurements Material from Theory and Design for Mechanical Measurements; Figliola, Third Edition Flow Rate Flow rate can be expressed in terms of volume flow rate (volume/time) or mass
More information5Axis TestPiece Influence of Machining Position
5Axis TestPiece Influence of Machining Position Michael Gebhardt, Wolfgang Knapp, Konrad Wegener Institute of Machine Tools and Manufacturing (IWF), Swiss Federal Institute of Technology (ETH), Zurich,
More informationTurbulent Heat Transfer in a Horizontal Helically Coiled Tube
Heat Transfer Asian Research, 28 (5), 1999 Turbulent Heat Transfer in a Horizontal Helically Coiled Tube Bofeng Bai, Liejin Guo, Ziping Feng, and Xuejun Chen State Key Laboratory of Multiphase Flow in
More informationHeat Transfer Prof. Dr. Ale Kumar Ghosal Department of Chemical Engineering Indian Institute of Technology, Guwahati
Heat Transfer Prof. Dr. Ale Kumar Ghosal Department of Chemical Engineering Indian Institute of Technology, Guwahati Module No. # 04 Convective Heat Transfer Lecture No. # 03 Heat Transfer Correlation
More informationUsing Computational Fluid Dynamics (CFD) Simulation to Model Fluid Motion in Process Vessels on Fixed and Floating Platforms
Using Computational Fluid Dynamics (CFD) Simulation to Model Fluid Motion in Process Vessels on Fixed and Floating Platforms Dr. Ted Frankiewicz Dr. ChangMing Lee NATCO Group Houston, TX USA IBC 9 th
More informationNUCLEAR ENERGY RESEARCH INITIATIVE
NUCLEAR ENERGY RESEARCH INITIATIVE Experimental and CFD Analysis of Advanced Convective Cooling Systems PI: Victor M. Ugaz and Yassin A. Hassan, Texas Engineering Experiment Station Collaborators: None
More informationNUMERICAL INVESTIGATIONS ON HEAT TRANSFER IN FALLING FILMS AROUND TURBULENCE WIRES
NUMERICAL INVESTIGATIONS ON HEAT TRANSFER IN FALLING FILMS AROUND TURBULENCE WIRES Abstract H. Raach and S. Somasundaram Thermal Process Engineering, University of Paderborn, Paderborn, Germany Turbulence
More informationFully Coupled Automated Meshing with Adaptive Mesh Refinement Technology: CONVERGE CFD. New Trends in CFD II
Flame Front for a Spark Ignited Engine Using Adaptive Mesh Refinement (AMR) to Resolve Turbulent Flame Thickness New Trends in CFD II Fully Coupled Automated Meshing with Adaptive Mesh Refinement Technology:
More informationChapter 13 OPENCHANNEL FLOW
Fluid Mechanics: Fundamentals and Applications, 2nd Edition Yunus A. Cengel, John M. Cimbala McGrawHill, 2010 Lecture slides by Mehmet Kanoglu Copyright The McGrawHill Companies, Inc. Permission required
More informationFall 12 PHY 122 Homework Solutions #8
Fall 12 PHY 122 Homework Solutions #8 Chapter 27 Problem 22 An electron moves with velocity v= (7.0i  6.0j)10 4 m/s in a magnetic field B= (0.80i + 0.60j)T. Determine the magnitude and direction of the
More informationDimensional analysis is a method for reducing the number and complexity of experimental variables that affect a given physical phenomena.
Dimensional Analysis and Similarity Dimensional analysis is very useful for planning, presentation, and interpretation of experimental data. As discussed previously, most practical fluid mechanics problems
More informationID@GT prepared by Gabe Landes for T. Purdy 2009
Rapid prototyping is the automatic construction of physical objects using solid freeform fabrication. The first techniques for rapid prototyping became available in the late 1980s and were used to produce
More informationThe Influence of Aerodynamics on the Design of HighPerformance Road Vehicles
The Influence of Aerodynamics on the Design of HighPerformance Road Vehicles Guido Buresti Department of Aerospace Engineering University of Pisa (Italy) 1 CONTENTS ELEMENTS OF AERODYNAMICS AERODYNAMICS
More informationA Comparison of Analytical and Finite Element Solutions for Laminar Flow Conditions Near Gaussian Constrictions
A Comparison of Analytical and Finite Element Solutions for Laminar Flow Conditions Near Gaussian Constrictions by Laura Noelle Race An Engineering Project Submitted to the Graduate Faculty of Rensselaer
More informationCOMPUTATIONAL ANALYSIS OF CENTRIFUGAL COMPRESSOR WITH GROOVES ON CASING
INTERNATIONAL JOURNAL OF MECHANICAL ENGINEERING AND TECHNOLOGY (IJMET) International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 6340(Print), ISSN ISSN 0976 6340 (Print) ISSN 0976
More informationExperimental Study of Free Convection Heat Transfer From Array Of Vertical Tubes At Different Inclinations
Experimental Study of Free Convection Heat Transfer From Array Of Vertical Tubes At Different Inclinations A.Satyanarayana.Reddy 1, Suresh Akella 2, AMK. Prasad 3 1 Associate professor, Mechanical Engineering
More informationNUMERICAL ANALYSIS FOR TWO PHASE FLOW DISTRIBUTION HEADERS IN HEAT EXCHANGERS
NUMERICAL ANALYSIS FOR TWO PHASE FLOW DISTRIBUTION HEADERS IN HEAT EXCHANGERS B.Babu 1, Florence.T 2, M.Punithavalli 3, B.R.Rohit 4 1 Assistant professor, Department of mechanical engineering, Rathinam
More informationLearning Module 4  Thermal Fluid Analysis Note: LM4 is still in progress. This version contains only 3 tutorials.
Learning Module 4  Thermal Fluid Analysis Note: LM4 is still in progress. This version contains only 3 tutorials. Attachment C1. SolidWorksSpecific FEM Tutorial 1... 2 Attachment C2. SolidWorksSpecific
More information2.0 BASIC CONCEPTS OF OPEN CHANNEL FLOW MEASUREMENT
2.0 BASIC CONCEPTS OF OPEN CHANNEL FLOW MEASUREMENT Open channel flow is defined as flow in any channel where the liquid flows with a free surface. Open channel flow is not under pressure; gravity is the
More informationFLOW PATTERNS AND EXCHANGE PROCESSES IN DEAD ZONES OF RIVERS VOLKER WEITBRECHT & GERHARD H. JIRKA
FLOW PATTERNS AND EXCHANGE PROCESSES IN DEAD ZONES OF RIVERS VOLKER WEITBRECHT & GERHARD H. JIRKA Institute for Hydromechanics, University of Karlsruhe 76128 Karlsruhe, Germany weitbrecht@ifh.unikarlsruhe.de
More informationPerformance prediction of a centrifugal pump working in direct and reverse mode using Computational Fluid Dynamics
European Association for the Development of Renewable Energies, Environment and Power Quality (EA4EPQ) International Conference on Renewable Energies and Power Quality (ICREPQ 10) Granada (Spain), 23rd
More informationSimple CFD Simulations and Visualisation using OpenFOAM and ParaView. Sachiko Arvelius, PhD
Simple CFD Simulations and Visualisation using OpenFOAM and ParaView Sachiko Arvelius, PhD Purpose of this presentation To show my competence in CFD (Computational Fluid Dynamics) simulation and visualisation
More informationComparison of Heat Transfer between a Helical and Straight Tube Heat Exchanger
International Journal of Engineering Research and Technology. ISSN 09743154 Volume 6, Number 1 (2013), pp. 3340 International Research Publication House http://www.irphouse.com Comparison of Heat Transfer
More informationKeywords: CFD, heat turbomachinery, Compound Lean Nozzle, Controlled Flow Nozzle, efficiency.
CALCULATION OF FLOW CHARACTERISTICS IN HEAT TURBOMACHINERY TURBINE STAGE WITH DIFFERENT THREE DIMENSIONAL SHAPE OF THE STATOR BLADE WITH ANSYS CFX SOFTWARE A. Yangyozov *, R. Willinger ** * Department
More informationDiurnal Cycle of Convection at the ARM SGP Site: Role of LargeScale Forcing, Surface Fluxes, and Convective Inhibition
Thirteenth ARM Science Team Meeting Proceedings, Broomfield, Colorado, March 31April 4, 23 Diurnal Cycle of Convection at the ARM SGP Site: Role of LargeScale Forcing, Surface Fluxes, and Convective
More informationHEAT TRANSFER AUGMENTATION THROUGH DIFFERENT PASSIVE INTENSIFIER METHODS
HEAT TRANSFER AUGMENTATION THROUGH DIFFERENT PASSIVE INTENSIFIER METHODS P.R.Hatwar 1, Bhojraj N. Kale 2 1, 2 Department of Mechanical Engineering Dr. Babasaheb Ambedkar College of Engineering & Research,
More informationThe process components and related data characteristics addressed in this document are:
TM Tech Notes Certainty 3D November 1, 2012 To: General Release From: Ted Knaak Certainty 3D, LLC Re: Structural Wall Monitoring (#1017) rev: A Introduction TopoDOT offers several tools designed specifically
More informationCHAPTER 4 FLOW IN CHANNELS
CHAPTER 4 FLOW IN CHANNELS INTRODUCTION 1 Flows in conduits or channels are of interest in science, engineering, and everyday life. Flows in closed conduits or channels, like pipes or air ducts, are entirely
More informationTHE PSEUDO SINGLE ROW RADIATOR DESIGN
International Journal of Mechanical Engineering and Technology (IJMET) Volume 7, Issue 1, JanFeb 2016, pp. 146153, Article ID: IJMET_07_01_015 Available online at http://www.iaeme.com/ijmet/issues.asp?jtype=ijmet&vtype=7&itype=1
More informationApplied Fluid Mechanics
Applied Fluid Mechanics Sixth Edition Robert L. Mott University of Dayton PEARSON Prentkv Pearson Education International CHAPTER 1 THE NATURE OF FLUIDS AND THE STUDY OF FLUID MECHANICS 1.1 The Big Picture
More informationFluid Mechanics Prof. T. I. Eldho Department of Civil Engineering Indian Institute of Technology, Bombay. Lecture No. # 36 Pipe Flow Systems
Fluid Mechanics Prof. T. I. Eldho Department of Civil Engineering Indian Institute of Technology, Bombay Lecture No. # 36 Pipe Flow Systems Welcome back to the video course on Fluid Mechanics. In today
More informationOpenFOAM simulations of the Turbulent Flow in a Rod Bundle with Mixing Vanes
OpenFOAM simulations of the Turbulent Flow in a Rod Bundle with Mixing Vanes ABSTRACT Blaž Mikuž Reactor Engineering Division, Jozef Stefan Institute, Jamova cesta 39 SI1000 Ljubljana, Slovenia blaz.mikuz@ijs.si
More informationInternational journal of Engineering ResearchOnline A Peer Reviewed International Journal Articles available online http://www.ijoer.
REVIEW ARTICLE ISSN: 23217758 REVIEW OF HEAT TRANSFER AUGMENTATION TECHNIQUES MANOJ HAJARE, CHETAN DEORE, KAVITA KHARDE, PUSHKAR RAWALE, VIVEK DALVI Department of Mechanical Engineering, SITRC, NASHIK
More informationDiffusion and Fluid Flow
Diffusion and Fluid Flow What determines the diffusion coefficient? What determines fluid flow? 1. Diffusion: Diffusion refers to the transport of substance against a concentration gradient. ΔS>0 Mass
More informationTHERMAL STRATIFICATION IN A HOT WATER TANK ESTABLISHED BY HEAT LOSS FROM THE TANK
THERMAL STRATIFICATION IN A HOT WATER TANK ESTABLISHED BY HEAT LOSS FROM THE TANK J. Fan and S. Furbo Abstract Department of Civil Engineering, Technical University of Denmark, Brovej, Building 118, DK28
More informationPart IV. Conclusions
Part IV Conclusions 189 Chapter 9 Conclusions and Future Work CFD studies of premixed laminar and turbulent combustion dynamics have been conducted. These studies were aimed at explaining physical phenomena
More informationSolid shape molding is not desired in injection molding due to following reasons.
PLASTICS PART DESIGN and MOULDABILITY Injection molding is popular manufacturing method because of its highspeed production capability. Performance of plastics part is limited by its properties which
More informationLecture 14. Introduction to the Sun
Lecture 14 Introduction to the Sun ALMA discovers planets forming in a protoplanetary disc. Open Q: what physics do we learn about the Sun? 1. Energy  nuclear energy  magnetic energy 2. Radiation  continuum
More informationAPPLICATION OF TRANSIENT WELLBORE SIMULATOR TO EVALUATE DELIVERABILITY CURVE ON HYPOTHETICAL WELLX
PROCEEDINGS, ThirtyThird Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, California, January 830, 008 SGPTR185 APPLICATION OF TRANSIENT WELLBORE SIMULATOR TO EVALUATE DELIVERABILITY
More informationEffects of Cell Phone Radiation on the Head. BEE 4530 ComputerAided Engineering: Applications to Biomedical Processes
Effects of Cell Phone Radiation on the Head BEE 4530 ComputerAided Engineering: Applications to Biomedical Processes Group 3 Angela Cai Youjin Cho Mytien Nguyen Praveen Polamraju Table of Contents I.
More informationConstruction of human knee bone joint model using FDM based 3D Printer from CT scan images.
Biomedical Research 2015; 26 (4): S15 ISSN 0970938X www.biomedres.info Construction of human knee bone joint model using FDM based 3D Printer from CT scan images. Marlon Jones Louis a *, R. Malayalamurthi
More informationFLUID FLOW STREAMLINE LAMINAR FLOW TURBULENT FLOW REYNOLDS NUMBER
VISUAL PHYSICS School of Physics University of Sydney Australia FLUID FLOW STREAMLINE LAMINAR FLOW TURBULENT FLOW REYNOLDS NUMBER? What type of fluid flow is observed? The above pictures show how the effect
More informationFundamentals of Heat and Mass Transfer
2008 AGIInformation Management Consultants May be used for personal purporses only or by libraries associated to dandelon.com network. SIXTH EDITION Fundamentals of Heat and Mass Transfer FRANK P. INCROPERA
More informationIntroduction to COMSOL. The NavierStokes Equations
Flow Between Parallel Plates Modified from the COMSOL ChE Library module rev 10/13/08 Modified by Robert P. Hesketh, Chemical Engineering, Rowan University Fall 2008 Introduction to COMSOL The following
More informationEffect of Rack Server Population on Temperatures in Data Centers
Effect of Rack Server Population on Temperatures in Data Centers Rajat Ghosh, Vikneshan Sundaralingam, Yogendra Joshi G.W. Woodruff School of Mechanical Engineering Georgia Institute of Technology, Atlanta,
More informationdu u U 0 U dy y b 0 b
BASIC CONCEPTS/DEFINITIONS OF FLUID MECHANICS (by Marios M. Fyrillas) 1. Density (πυκνότητα) Symbol: 3 Units of measure: kg / m Equation: m ( m mass, V volume) V. Pressure (πίεση) Alternative definition:
More informationEssay 5 Tutorial for a ThreeDimensional Heat Conduction Problem Using ANSYS Workbench
Essay 5 Tutorial for a ThreeDimensional Heat Conduction Problem Using ANSYS Workbench 5.1 Introduction The problem selected to illustrate the use of ANSYS software for a threedimensional steadystate
More informationComputational Fluid Dynamics Investigation of Two Surfboard Fin Configurations.
Computational Fluid Dynamics Investigation of Two Surfboard Fin Configurations. By: Anthony Livanos (10408690) Supervisor: Dr Philippa O Neil Faculty of Engineering University of Western Australia For
More informationExperiment 3 Pipe Friction
EML 316L Experiment 3 Pipe Friction Laboratory Manual Mechanical and Materials Engineering Department College of Engineering FLORIDA INTERNATIONAL UNIVERSITY Nomenclature Symbol Description Unit A crosssectional
More informationLecture 14. Point Spread Function (PSF)
Lecture 14 Point Spread Function (PSF), Modulation Transfer Function (MTF), Signaltonoise Ratio (SNR), Contrasttonoise Ratio (CNR), and Receiver Operating Curves (ROC) Point Spread Function (PSF) Recollect
More informationFREE CONVECTION FROM OPTIMUM SINUSOIDAL SURFACE EXPOSED TO VERTICAL VIBRATIONS
International Journal of Mechanical Engineering and Technology (IJMET) Volume 7, Issue 1, JanFeb 2016, pp. 214224, Article ID: IJMET_07_01_022 Available online at http://www.iaeme.com/ijmet/issues.asp?jtype=ijmet&vtype=7&itype=1
More informationCustomer Training Material. Lecture 2. Introduction to. Methodology ANSYS FLUENT. ANSYS, Inc. Proprietary 2010 ANSYS, Inc. All rights reserved.
Lecture 2 Introduction to CFD Methodology Introduction to ANSYS FLUENT L21 What is CFD? Computational Fluid Dynamics (CFD) is the science of predicting fluid flow, heat and mass transfer, chemical reactions,
More informationExperimentation and Computational Fluid Dynamics Modelling of Roughness Effects in Flexible Pipelines
Experimentation and Computational Fluid Dynamics Modelling of Roughness Effects in Flexible Pipelines Sophie Yin Jeremy Leggoe School of Mechanical and Chemical Engineering Daniel Teng Paul Pickering CEED
More informationPASSIVE CONTROL OF SHOCK WAVE APPLIED TO HELICOPTER ROTOR HIGHSPEED IMPULSIVE NOISE REDUCTION
TASK QUARTERLY 14 No 3, 297 305 PASSIVE CONTROL OF SHOCK WAVE APPLIED TO HELICOPTER ROTOR HIGHSPEED IMPULSIVE NOISE REDUCTION PIOTR DOERFFER AND OSKAR SZULC Institute of FluidFlow Machinery, Polish Academy
More information19 th INTERNATIONAL CONGRESS ON ACOUSTICS MADRID, 27 SEPTEMBER 2007 THE SOUND FIELD IN AN EAR CANAL OCCLUDED BY A HEARING AID
19 th INTERNATIONAL CONGRESS ON ACOUSTICS MADRID, 27 SEPTEMBER 27 THE SOUND FIELD IN AN EAR CANAL OCCLUDED BY A HEARING AID PACS: 43.66.Ts, 43.64.Ha, 43.38.Kb, 43.2.Mv Stinson, Michael R.; Daigle, Gilles
More informationEXPERIMENTAL ANALYSIS OF PARTIAL AND FULLY CHARGED THERMAL STRATIFIED HOT WATER STORAGE TANKS
INTERNATIONAL JOURNAL OF MECHANICAL ENGINEERING AND TECHNOLOGY (IJMET) International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 6340(Print), ISSN 0976 6340 (Print) ISSN 0976 6359
More informationInternational Journal of Latest Research in Science and Technology Volume 4, Issue 2: Page No.161166, MarchApril 2015
International Journal of Latest Research in Science and Technology Volume 4, Issue 2: Page No.161166, MarchApril 2015 http://www.mnkjournals.com/ijlrst.htm ISSN (Online):22785299 EXPERIMENTAL STUDY
More informationBasic Principles in Microfluidics
Basic Principles in Microfluidics 1 Newton s Second Law for Fluidics Newton s 2 nd Law (F= ma) : Time rate of change of momentum of a system equal to net force acting on system!f = dp dt Sum of forces
More informationCFD SIMULATION OF SDHW STORAGE TANK WITH AND WITHOUT HEATER
International Journal of Advancements in Research & Technology, Volume 1, Issue2, July2012 1 CFD SIMULATION OF SDHW STORAGE TANK WITH AND WITHOUT HEATER ABSTRACT (1) Mr. Mainak Bhaumik M.E. (Thermal Engg.)
More informationINTRODUCTION TO FLUID MECHANICS
INTRODUCTION TO FLUID MECHANICS SIXTH EDITION ROBERT W. FOX Purdue University ALAN T. MCDONALD Purdue University PHILIP J. PRITCHARD Manhattan College JOHN WILEY & SONS, INC. CONTENTS CHAPTER 1 INTRODUCTION
More informationCHAPTER: 6 FLOW OF WATER THROUGH SOILS
CHAPTER: 6 FLOW OF WATER THROUGH SOILS CONTENTS: Introduction, hydraulic head and water flow, Darcy s equation, laboratory determination of coefficient of permeability, field determination of coefficient
More information