# Optimum fin spacing for fan-cooled heat sinks

Save this PDF as:

Size: px
Start display at page:

Download "Optimum fin spacing for fan-cooled heat sinks"

## Transcription

1 Optimum fin spacing for fan-cooled heat sinks Keywords: optimum fin spacing fan-cooled heat sink heatsink optimal fin pitch parallel plate fin array optimization forced air cooling fan curve pressure drop maximum fin density baseplate backplane fin height thermal management improving performance This paper discusses the optimum fin spacing for a fan-cooled heat sink. The heat sink geometry is shown in Figure 1. As shown in the figure, it is assumed that a shroud is present to confine air flow to the fin channels. fin spacing (fin-to-fin air gap) 1.2 L fin Air Flow 150 L flow shroud heat sink no air gap between shroud and tips of fins Figure 1: Heat sink and shroud configuration Figure 2 is a schematic of the overall flow system: shroud Fan Heat Sink Figure 2: Overall flow system Thermal Solutions Inc S. State St. Suite 108 Ann Arbor MI Phone: Fax:

2 Flow, pressure and heat transfer calculations When a fan or blower forces air through a heat sink, the flow obtained will be a function of both the fan capacity and the flow resistance of the heat sink. Figure 3 shows the flow and pressure characteristics for a typical fan. As shown, the amount of air pressure that a fan can generate depends on the air flow. While the fan in the figure is rated at 50 CFM (85 m3/hr), this flow rate will not be obtained when combined with a heat sink, because air pressure is needed to force the air through the fin channels. Pressure (Pa) fan curve Volume Flow (CFM) Figure 3: Flow and pressure characteristics of a typical axial fan Figure 4 adds a flow resistance curve. The intersection between the fan curve and the flow resistance curve is the operating point of the system. This point represents the actual air volume which will pass through the heat sink fin channels. (Depending on the shape of the fan curve, it is actually possible to have two operating points, although this is a condition for the designer to avoid.) Pressure (Pa) operating point flow resistance curve transition to turbulence fan curve Volume Flow (CFM) Figure 4: Flow and pressure characteristics of fan and heat sink combination 2

3 The fan curve for a particular fan model is obtained from the manufacturer of the fan. The system flow resistance can be calculated with a form of the Bernoulli equation: p = [ Vlocal 2 (K + 4 f Lflow) ] ρ 2 Dhyd It is important to realize that the heat sink is only part of the system flow resistance. The fan must overcome all of the flow resistance elements, which includes the heat sink, inlet and outlet grilles, any filters, etc. If it can be assumed that: (a) inlet and outlet grilles are largely open area, (b) no air filters are present and (c) there is a straight-through flow path, the system will be largely the same as in Figure 2. In this case, the Bernoulli equation can be simplified to: p overall = (Kc + 4 f Lflow + Ke) ρ Vchan 2 D hyd 2 where: p overall - total pressure drop for the flow circuit V chan - average air velocity within the fin channels K c - loss coefficient for contraction into the fin channels K e - loss coefficient for expansion as air exits the fin channels f - friction factor in the fin channels D hyd - hydraulic diameter for the fin channels ρ - average air density within the fin channels To calculate laminar flow volume and pressure drop, the method outlined by Robert Simons [1], based on equations from Culham and Muzychka [2], was used. Since the fan must push against the system flow resistance, it was appropriate to evaluate the K factors at σ = 1.0, so that K c = 0.42 and Ke = 1.0. For the turbulent flow regime, the base friction factor was obtained from the Petukhov equation [3], with an entry correction factor derived from Deissler [4]. The K factors were obtained from Kays and London [5], which yields K c = 0.5 and Ke =1.0, again for σ = 1.0. To calculate heat transfer from the fins, a parallel plate model was used which takes into account entrance effects [6][7][8]. Flow can be either laminar or turbulent. There is a correction factor for the temperature rise of the air as it moves through the fin channels, as well as a fin efficiency correction factor. The heat sink baseplate was fixed at 75 C and the inlet air temperature was 25 C. The base-to-tip fin length (L fin ) was 25 mm, unless specified otherwise. Fin thickness was 1.2 mm with a thermal conductivity of W/m- C (typical for a conductive aluminum alloy). Unless noted otherwise, the fan has a maximum air flow of 50 CFM (85 m3/hr) and a static pressure rating of 25 pascals (0.1" H 2 O). These fan specifications are typical of a 92 mm DC axial fan. The fan was modeled with a simple straight-line fan curve. The actual calculations were performed with the Sauna V3.71 thermal program [9]. Fin spacing optimization at L flow = 150 mm (6 ) Before optimizing with a fan, it's quite instructive to obtain an optimization curve with a constant flow. Figure 5 on the next page shows a fin spacing optimization curve at a constant air flow volume of 25 CFM (42.5 m3/hr) and Lfin = 25 mm. Note that, as shown in Figure 1, 3

4 fin spacing refers to the fin-to-fin air gap. The figure shows that the optimum fin spacing is just 0.5 mm (.020 ). However, the pressure drop at this fin spacing is a very elevated 1662 Pa (6.7 H 2 O). It would take a massive fan to force this amount of air through the heat sink. Constant flow of 25 CFM transition to turbulence Optimum fin spacing Figure 5: Fin spacing optimization at constant flow volume The results are quite different when a fan is used, as shown in Figure 6. The optimum fin spacing is roughly 2.8 mm (0.11 ), significantly larger than before. At the optimum point of the curve, there is the best possible balance between high heat transfer coefficients at close fin spacings and reduced flow due to the increased pressure drop associated with narrow fin channels. L flow = 150 mm transition to turbulence Optimum = 2.8 mm Figure 6: Optimum fin spacing with fan 4

5 There are several interesting points to mention about Figure 6. First, notice the optimum fin spacing occurs in the laminar flow regime, which is usually the case. However, as discussed later, there are situations where the optimum occurs within the turbulent flow regime. Second, the optimum heat sink has fins which are relatively closely spaced. It will not be possible to achieve this optimum spacing with an inexpensive heat sink. A low cost extruded heat sink typically has a fin spacing of 6 mm, significantly greater than the optimum of 2.8 mm. It will be necessary to use bonded or swaged fins. Such a heat sink will cost more, but will provide a significant benefit. Finally, there is a significant penalty for having a fin spacing which is less than the optimum. On the other hand, the penalty is not as severe for a fin spacing which is greater than optimum, so it is better to err in this direction. Spacing optimization at L flow = 300 mm (12 ) The optimization curve for Lflow = 300 mm is shown in Figure 7. The shape of the curve is similar to L flow = 150 mm. However, the optimum spacing occurs at 4.0 mm, which is 40% greater than before. There are two reasons for this. First, a longer heat sink has greater flow resistance and this will cause the fan to deliver less air volume. Second, the longer fin channels fill up with warm air, which causes a reduction in heat transfer. Optimum = 4.0 L flow = 300 mm Figure 7: Optimum fin spacing for 300 mm flow length It's also interesting to examine an optimization curve for a shorter flow length. Figure 8 on the next page shows curves for flow lengths of 75, 150 and 300 mm. For L flow = 75 mm, the optimum fin spacing is reduced to 2.0 mm, just half the optimum value for L flow = 300 mm. Figure 8 clearly illustrate the danger of using a fin spacing which is less than the optimum. Note the performance of the L flow = 300 mm heat sink with fin spacing = 2.0 mm. In this 5

6 L flow = 75 mm L flow = 150 mm L flow = 300 mm Optimum spacing = 2.0 mm for L flow = 75 Figure 8: Optimum fin spacing for multiple flow lengths case, the performance is degraded so sharply that it would actually be more effective to use a shorter heat sink, either L flow = 75 or Lflow = 150, at the same spacing! Expensive sinks with closely spaced fins can be very effective in the proper application, but disastrous results will occur if the heat sink is misused. Impact of varying fan capacity In the real world, a designer can change either the heat sink or the fan (or both). So it is interesting to see how changes in fan capacity affect performance and optimum dimensions. Figure 8 shows optimum fin spacing at different fan capacities. All previous graphs have assumed a fan with maximum flow of 50 CFM and a maximum pressure of 25 pascals. So the curves in Figure 8 show the effects of doubling flow and pressure, as well as halving these parameters. L flow = 150 mm 25 CFM / 12.5 Pa 50 CFM / 25 Pa 100 CFM / 50 Pa Figure 9: Effect of varying fan capacity 6

7 Not surprisingly, the lowest thermal resistance is obtained with the most powerful fan. The optimum spacing is also affected, with a smaller optimum spacing for the higher power fan. However, the fin spacing effect is much smaller as compared with changing the overall length of the heat sink. The optimum spacing for the 25 CFM/12.5 Pa fan is 3.3 mm, which decreases to 2.4 mm for the 100 CFM/50 Pa fan. This is a fairly modest shift considering that there is a 4:1 difference in both pressure and maximum flow. The flow length has a much stronger impact on optimum fin spacing. Besides fin spacing, there is also a clear change in the transition point for the shift to turbulent flow. Since the most powerful fan is generating the most flow, turbulence occurs at a lesser fin spacing. Also, notice the shape of the curve for the 100 CFM/50 Pa fan. Thermal resistance at the start of the turbulent regime is fairly close to the optimum thermal resistance located in the laminar regime. With an even more powerful fan, in fact, the optimum spacing would occur in the turbulent regime. (It should also be pointed out that it is difficult to predict heat transfer with great accuracy at the start of the turbulent zone.) Impact of varying fin length Finally, it is also interesting to look at the change in performance and optimum fin spacing as the base-to-tip fin length (L fin ) is modified. Figure 8 shows both shorter and longer Lfin as compared with the fin length of 25 mm used in the previous graphs. Figure 8 was generated with the default 50 CFM/25 Pa fan. L fin = 12.5 mm L flow = 150 mm L fin = 25 mm L fin = 37.5 mm L fin = 50 mm Figure 10: Effect of varying base-to-tip fin length As far as fin spacing is concerned, the optimum spacing is nearly unchanged for the 4 different values of fin length. Figure 8 shows very limited gains as the fin length starts to approach 50 mm (2"), which is surprising to some. The longer fins do provide larger fin channels, which reduces flow resistance. This, in turn, increases total volume flow through the heat sink. However, the linear air velocity is reduced because the increase in volume flow does not keep up with the increased 7

### Fan-plus-Heatsink Optimization Mechanical and Thermal Design with Reality

Fan-plus-Heatsink Optimization Mechanical and Thermal Design with Reality Catharina R. Biber, Ph.D. InFocus Systems, Inc. 277B SW Parkway Avenue Wilsonville, OR 977 53-685-8654 voice 53-685-8842 fax Crbiber@alum.mit.edu

### Comparing naturally cooled horizontal baseplate heat sinks with vertical baseplate heat sinks

Comparing naturally cooled horizontal baseplate heat sinks with vertical baseplate heat sinks Keywords: heat sink heatsink fin array natural convection natural cooling free convection horizontal baseplate

### EFFECT OF OBSTRUCTION NEAR FAN INLET ON FAN HEAT SINK PERFORMANCE

EFFECT OF OBSTRUCTION NEAR FAN INLET ON FAN HEAT SINK PERFORMANCE Vivek Khaire, Dr. Avijit Goswami Applied Thermal Technologies India 3rd Floor,C-Wing,Kapil Towers, Dr. Ambedkar Road, Pune- 411 1 Maharashtra,

### A 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

### Battery Thermal Management System Design Modeling

Battery Thermal Management System Design Modeling Gi-Heon Kim, Ph.D Ahmad Pesaran, Ph.D (ahmad_pesaran@nrel.gov) National Renewable Energy Laboratory, Golden, Colorado, U.S.A. EVS October -8, 8, 006 Yokohama,

### Flow Loss in Screens: A Fresh Look at Old Correlation. Ramakumar Venkata Naga Bommisetty, Dhanvantri Shankarananda Joshi and Vighneswara Rao Kollati

Journal of Mechanics Engineering and Automation 3 (013) 9-34 D DAVID PUBLISHING Ramakumar Venkata Naga Bommisetty, Dhanvantri Shankarananda Joshi and Vighneswara Rao Kollati Engineering Aerospace, MCOE,

### THERMAL ANALYSIS OF WATER COOLED CHARGE AIR COOLER IN TURBO CHARGED DIESEL ENGINE

THERMAL ANALYSIS OF WATER COOLED CHARGE AIR COOLER IN TURBO CHARGED DIESEL ENGINE J.N. Devi Sankar 1, P.S.Kishore 2 1 M.E. (Heat transfer in Energy Systems) Student, Department of Mechanical Engineering,

### CFD SIMULATION OF SDHW STORAGE TANK WITH AND WITHOUT HEATER

International Journal of Advancements in Research & Technology, Volume 1, Issue2, July-2012 1 CFD SIMULATION OF SDHW STORAGE TANK WITH AND WITHOUT HEATER ABSTRACT (1) Mr. Mainak Bhaumik M.E. (Thermal Engg.)

### Experimental &Theoretical Investigation of Pressure Drop across Tube Bundle of a THPHE and Introducing a New Correlation

Experimental &Theoretical Investigation of Pressure Drop across Tube Bundle of a THPHE and Introducing a New Correlation Zare aliabadi *, Hassan Department of chemical engineering, Islamic Azad University

### 1150 hp motor design, electromagnetic and thermal analysis

115 hp motor design, electromagnetic and thermal analysis Qasim Al Akayshee 1, and David A Staton 2 1 Mawdsley s Ltd., The Perry Centre, Davey Close, Waterwells, Gloucester GL2 4AD phone: +44 1452 888311

### Entrance Conditions. Chapter 8. Islamic Azad University

Chapter 8 Convection: Internal Flow Islamic Azad University Karaj Branch Entrance Conditions Must distinguish between entrance and fully developed regions. Hydrodynamic Effects: Assume laminar flow with

### Applied Fluid Mechanics

Applied Fluid Mechanics 1. The Nature of Fluid and the Study of Fluid Mechanics 2. Viscosity of Fluid 3. Pressure Measurement 4. Forces Due to Static Fluid 5. Buoyancy and Stability 6. Flow of Fluid and

### Module 2 : Convection. Lecture 20a : Illustrative examples

Module 2 : Convection Lecture 20a : Illustrative examples Objectives In this class: Examples will be taken where the concepts discussed for heat transfer for tubular geometries in earlier classes will

### Integration of a fin experiment into the undergraduate heat transfer laboratory

Integration of a fin experiment into the undergraduate heat transfer laboratory H. I. Abu-Mulaweh Mechanical Engineering Department, Purdue University at Fort Wayne, Fort Wayne, IN 46805, USA E-mail: mulaweh@engr.ipfw.edu

### Comparison of Heat Transfer between a Helical and Straight Tube Heat Exchanger

International Journal of Engineering Research and Technology. ISSN 0974-3154 Volume 6, Number 1 (2013), pp. 33-40 International Research Publication House http://www.irphouse.com Comparison of Heat Transfer

### Natural 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

### An Automotive Radiator Employing Wickless Heat Pipes

An Automotive Radiator Employing Wickless Heat Pipes Yiding Cao and Khokiat Kengskool 2 Abstract: Heat pipe is a heat transfer device that may have a thermal conductance hundreds of times higher than that

### Theoretical and Experimental Investigation of Heat Transfer Characteristics through a Rectangular Microchannel Heat Sink

Theoretical and Experimental Investigation of Heat Transfer Characteristics through a Rectangular Microchannel Heat Sink Dr. B. S. Gawali 1, V. B. Swami 2, S. D. Thakre 3 Professor Dr., Department of Mechanical

### HEAT 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,

### Permanent Magnet DC Motor Brush Transient Thermal Analysis

Paper ID 1109 Permanent Magnet DC Motor Brush Transient Thermal Analysis Jacek Junak 1, Grzegorz Ombach 1, Dave Staton 2 1 VDO Automotive AG, Werner-von-Siemens 3, D-97076, Wuerzburg, Germany 2 Motor Design

### ANALYSIS OF FULLY DEVELOPED TURBULENT FLOW IN A PIPE USING COMPUTATIONAL FLUID DYNAMICS D. Bhandari 1, Dr. S. Singh 2

ANALYSIS OF FULLY DEVELOPED TURBULENT FLOW IN A PIPE USING COMPUTATIONAL FLUID DYNAMICS D. Bhandari 1, Dr. S. Singh 2 1 M. Tech Scholar, 2 Associate Professor Department of Mechanical Engineering, Bipin

### Fan Basics and Selection Criteria (How to Use)

Feature: Understanding SANYO DENKI Products from Scratch Fan Basics and Selection Criteria (How to Use) Honami Osawa 1. Introduction In recent years, the importance of cooling technology has become even

### Thermal Analysis on Dynamic Braking Resistor Unit

Thermal Analysis on Dynamic Braking Resistor Unit B.Praveen Kumar Swami Vivekananda Institute of Technology, Hyderabad. B.Venkatesh Vardhaman College of Engineering, Hyderabad ABSTRACT Dynamic brakes are

### Sizing of triple concentric pipe heat exchanger

Sizing of triple concentric pipe heat exchanger 1 Tejas M. Ghiwala, 2 Dr. V.K. Matawala 1 Post Graduate Student, 2 Head of Department 1 Thermal Engineering, SVMIT, Bharuch-392001, Gujarat, INDIA, 2 Department

### Characteristics of Centrifugal Blower and Its Effective Use in High Static Pressure Area

Characteristics of Centrifugal Blower and Its Effective Use in High Static Pressure Area Masayuki TAKAHASHI With small fans, selecting the right fan that most fits the purpose is extremely important from

### Applied 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

### DEVELOPMENT OF HIGH SPEED RESPONSE LAMINAR FLOW METER FOR AIR CONDITIONING

DEVELOPMENT OF HIGH SPEED RESPONSE LAMINAR FLOW METER FOR AIR CONDITIONING Toshiharu Kagawa 1, Yukako Saisu 2, Riki Nishimura 3 and Chongho Youn 4 ABSTRACT In this paper, we developed a new laminar flow

### Lecture 5 Hemodynamics. Description of fluid flow. The equation of continuity

1 Lecture 5 Hemodynamics Description of fluid flow Hydrodynamics is the part of physics, which studies the motion of fluids. It is based on the laws of mechanics. Hemodynamics studies the motion of blood

### FLUID FLOW Introduction General Description

FLUID FLOW Introduction Fluid flow is an important part of many processes, including transporting materials from one point to another, mixing of materials, and chemical reactions. In this experiment, you

### Review: Convection and Heat Exchangers. Reminders

CH EN 3453 Heat Transfer Review: Convection and Heat Exchangers Chapters 6, 7, 8, 9 and 11 Reminders Midterm #2 Wednesday at 8:15 AM Review tomorrow 3:30 PM in WEB L104 (I think) Project Results and Discussion

### Dependency of heat transfer rate on the Brinkman number in microchannels

Dependency of heat transfer rate on the Brinkman number in microchannels Hee Sung Park Stokes Institute, University of Limerick, Limerick, Ireland Abstract Heat generation from electronics increases with

### 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)

### ME 144: Heat Transfer Convection Relations for External Flows. J. M. Meyers

ME 144: Heat Transfer Convection Relations for External Flows Empirical Correlations Generally, convection correlations for external flows are determined experimentally using controlled lab conditions

### A Study on Basic Water Cooling System of Gas Compressor Engine

A Study on Basic Water Cooling System of Gas Compressor Engine P. Praveen Babu 1, B. Siddeswara Rao 2, S. Jaya Kishore 3 1 PG student, Thermal Engineering, Siddharth Institute of Engineering and Technology,

### A MTR FUEL ELEMENT FLOW DISTRIBUTION MEASUREMENT PRELIMINARY RESULTS

A MTR FUEL ELEMENT FLOW DISTRIBUTION MEASUREMENT PRELIMINARY RESULTS W. M. Torres, P. E. Umbehaun, D. A. Andrade and J. A. B. Souza Centro de Engenharia Nuclear Instituto de Pesquisas Energéticas e Nucleares

### Experiment 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 cross-sectional

### NUMERICAL 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

### Airflow through Mine Openings and Ducts Chapter 5

Airflow through Mine Openings and Ducts Chapter 5 Fundamentals of Airflow Ventilation the application of the principles of fluid mechanics & thermodynamics to the flow of air in underground openings Fluid

### MATLAB AS A PROTOTYPING TOOL FOR HYDRONIC NETWORKS BALANCING

MATLAB AS A PROTOTYPING TOOL FOR HYDRONIC NETWORKS BALANCING J. Pekař, P. Trnka, V. Havlena* Abstract The objective of this note is to describe the prototyping stage of development of a system that is

### ) and the maximum airflow setpoint (V max

The following article was published in ASHRAE Journal, March 004. Copyright 004 American Society of Heating, Refrigerating and Air- Conditioning Engineers, Inc. It is presented for educational purposes

### SHELL & TUBE HEAT EXCHANGER STEADY STATE

SHELL & TUBE HEAT EXCHANGER STEADY STATE This case study demonstrates the steady-state thermal fluid simulation of a shell and tube heat exchanger. The shell and tube heat exchanger model can also be used

### AN EXPERIMENTAL STUDY OF EXERGY IN A CORRUGATED PLATE HEAT EXCHANGER

International Journal of Mechanical Engineering and Technology (IJMET) Volume 6, Issue 11, Nov 2015, pp. 16-22, Article ID: IJMET_06_11_002 Available online at http://www.iaeme.com/ijmet/issues.asp?jtype=ijmet&vtype=6&itype=11

### Convection Heat Transfer and Flow Calculations Suitable for Analytical Modelling of Electric Machines

Convection Heat Transfer and Flow Calculations Suitable for Analytical Modelling of Electric Machines D.A. Staton A. Cavagnino Motor Design Ltd Politecnico di Torino 1 Eaton Court, Tetchill, Ellesmere

### E 490 Fundamentals of Engineering Review. Fluid Mechanics. M. A. Boles, PhD. Department of Mechanical & Aerospace Engineering

E 490 Fundamentals of Engineering Review Fluid Mechanics By M. A. Boles, PhD Department of Mechanical & Aerospace Engineering North Carolina State University Archimedes Principle and Buoyancy 1. A block

### Thermal Modeling of NiMH Battery Powering Electric Vehicles

Proceedings of the 5th WSEAS Int. Conf. on System Science and Simulation in Engineering, Tenerife, Canary Islands, Spain, December 16-18, 06 5 Thermal ing of NiMH Battery Powering Electric Vehicles H.

### Comsol Laboration: Heat Conduction in a Chip

Comsol Laboration: Heat Conduction in a Chip JO, CSC January 11, 2012 1 Physical configuration A chip on a circuit board is heated inside and cooled by convection by the surrounding fluid. We consider

### Exergy Analysis of a Water Heat Storage Tank

Exergy Analysis of a Water Heat Storage Tank F. Dammel *1, J. Winterling 1, K.-J. Langeheinecke 3, and P. Stephan 1,2 1 Institute of Technical Thermodynamics, Technische Universität Darmstadt, 2 Center

### POURING THE MOLTEN METAL

HEATING AND POURING To perform a casting operation, the metal must be heated to a temperature somewhat above its melting point and then poured into the mold cavity to solidify. In this section, we consider

### The Effect of Forced Air Cooling on Heat Sink Thermal Ratings

zpero 1 The Effect of Forced Air Cooling on Heat Sink Thermal Ratings By Paul Bachman, Fellow Engineer & Ronnie Haiduk, Applications Engineer, Crydom, Inc. ABSTRACT A heat sink s ability to dissipate thermal

### Efficiency and Cost Tradeoffs Between Aluminum and Zinc- Aluminum Die Cast Heatsinks

Efficiency and Cost Tradeoffs Between and Zinc- Die Cast Heatsinks Kurtis P. Keller University of North Carolina, Computer Science Department Chapel Hill, NC 27599-3175, USA ABSTRACT High purity aluminum

### HEAT TRANSFER ENHANCEMENT IN FIN AND TUBE HEAT EXCHANGER - A REVIEW

HEAT TRANSFER ENHANCEMENT IN FIN AND TUBE HEAT EXCHANGER - A REVIEW Praful Date 1 and V. W. Khond 2 1 M. Tech. Heat Power Engineering, G.H Raisoni College of Engineering, Nagpur, Maharashtra, India 2 Department

### Design and Pressure Loss Reduction in the Hydrogen Flow Heat Exchanger with Tube Bundles

Design and Pressure Loss Reduction in the Hydrogen Flow Heat Exchanger with Tube Bundles By Ahmad, Ph.D. asleiti@mail.ucf.edu College of Engineering and Computer Science University of Central Florida Orlando,

### Enhancement of heat transfer of solar air heater roughened with circular transverse RIB

Enhancement of heat transfer of solar air heater roughened with circular transverse RIB Gurpreet Singh 1, Dr. G. S. Sidhu 2 Lala Lajpat Rai Institute of Engineering and Technology, Moga Punjab, India 1,2

### PRESSURE DROP ANALYSIS OF INLET PIPE WITH REDUCER AND WITHOUT REDUCER USING CFD ANALYSIS

International Journal of Mechanical Engineering (IJME) ISSN(P): 2319-2240; ISSN(E): 2319-2259 Vol. 4, Issue 3, Apr - May 2015, 85-92 IASET PRESSURE DROP ANALYSIS OF INLET PIPE WITH REDUCER AND WITHOUT

### International Journal of Latest Research in Science and Technology Volume 4, Issue 2: Page No.161-166, March-April 2015

International Journal of Latest Research in Science and Technology Volume 4, Issue 2: Page No.161-166, March-April 2015 http://www.mnkjournals.com/ijlrst.htm ISSN (Online):2278-5299 EXPERIMENTAL STUDY

### Effect 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,

### The examination rubric is: Answer THREE questions, from FIVE offered. All questions carry equal weight.

MODULE DESCRIPTOR MECHGM06 Heat Transfer and Heat Systems Code: MECHGM06 Alt. Codes(s) MECHGR06, MECHM007 Title: Heat Transfer and Heat Systems Level: M UCL Credits/ECTS: 15/6 Start: September End: March

### TWO-DIMENSIONAL FINITE ELEMENT ANALYSIS OF FORCED CONVECTION FLOW AND HEAT TRANSFER IN A LAMINAR CHANNEL FLOW

TWO-DIMENSIONAL FINITE ELEMENT ANALYSIS OF FORCED CONVECTION FLOW AND HEAT TRANSFER IN A LAMINAR CHANNEL FLOW Rajesh Khatri 1, 1 M.Tech Scholar, Department of Mechanical Engineering, S.A.T.I., vidisha

### THE PSEUDO SINGLE ROW RADIATOR DESIGN

International Journal of Mechanical Engineering and Technology (IJMET) Volume 7, Issue 1, Jan-Feb 2016, pp. 146-153, Article ID: IJMET_07_01_015 Available online at http://www.iaeme.com/ijmet/issues.asp?jtype=ijmet&vtype=7&itype=1

### TWO FLUXES MULTISTAGE INDUCTION COILGUN

Review of the Air Force Academy No 3 (30) 2015 TWO FLUXES MULTISTAGE INDUCTION COILGUN Laurian GHERMAN Henri Coandă Air Force Academy, Braşov, Romania DOI: 10.19062/1842-9238.2015.13.3.7 Abstract: This

### Fan Performance By: Mark Stevens AMCA International Deputy Executive Director Technical Affairs

Fan Performance By: Mark Stevens AMCA International Deputy Executive Director Technical Affairs Fan Performance (Paper I.D. 021) Mark Stevens Air Movement and Control Association International Abstract

### Laminar Flow and Heat Transfer of Herschel-Bulkley Fluids in a Rectangular Duct; Finite-Element Analysis

Tamkang Journal of Science and Engineering, Vol. 12, No. 1, pp. 99 107 (2009) 99 Laminar Flow and Heat Transfer of Herschel-Bulkley Fluids in a Rectangular Duct; Finite-Element Analysis M. E. Sayed-Ahmed

### Macroscopic Balances for Nonisothermal Systems

Transport Phenomena Macroscopic Balances for Nonisothermal Systems 1 Macroscopic Balances for Nonisothermal Systems 1. The macroscopic energy balance 2. The macroscopic mechanical energy balance 3. Use

### UNIVERSITY OF MINNESOTA DULUTH DEPARTMENT OF CHEMICAL ENGINEERING ChE MEASUREMENTS WITH FLOW METERS

UNIVERSITY OF MINNESOTA DULUTH DEPARTMENT OF CHEMICAL ENGINEERING ChE 3211-4211 MEASUREMENTS WITH FLOW METERS OBJECTIVE The purpose of this experiment is to calculate the coefficient of discharge from

### Thirty Questions with Answers about Economical, Eco-friendly Copper Tubes for Air Conditioner Applications

Q&A Thirty Questions with Answers about Economical, Eco-friendly Copper Tubes for Air Conditioner Applications Core Benefits 1. What are the major benefits of economical, eco-friendly copper tubes? Energy

### Department of Chemical Engineering, National Institute of Technology, Tiruchirappalli 620 015, Tamil Nadu, India

Experimental Thermal and Fluid Science 32 (2007) 92 97 www.elsevier.com/locate/etfs Studies on heat transfer and friction factor characteristics of laminar flow through a circular tube fitted with right

### TFM009. Investigation of Water Flow Rate in a Thermosyphon Solar Water Heater

The 19 th Annual Conference of Mechanical Engineering Network of Thailand October 19-1, 5, Songkla, Thailand Investigation of Water Flow Rate in a Thermosyphon Solar Water Heater Pisit Techarungpaisan

### MAXIMISING THE HEAT TRANSFER THROUGH FINS USING CFD AS A TOOL

MAXIMISING THE HEAT TRANSFER THROUGH FINS USING CFD AS A TOOL Sanjay Kumar Sharma 1 and Vikas Sharma 2 1,2 Assistant Professor, Department of Mechanical Engineering, Gyan Vihar University, Jaipur, Rajasthan,

### Problem Statement In order to satisfy production and storage requirements, small and medium-scale industrial

Problem Statement In order to satisfy production and storage requirements, small and medium-scale industrial facilities commonly occupy spaces with ceilings ranging between twenty and thirty feet in height.

### Fan Cooling at High Altitude

Fan Cooling at High Altitude Introduction This Lessons Learned addresses a cooling problem recently encountered while testing a fan cooled enclosure at high altitude. While we have successfully designed

### PIPE NETWORK ANALYSIS OF A COMPLEX FLOW SYSTEM USING PIPENET A CASE STUDY

International Journal of Mechanical Engineering and Technology (IJMET) Volume 6, Issue 9, Sep 2015, pp. 51-60, Article ID: IJMET_06_09_006 Available online at http://www.iaeme.com/ijmet/issues.asp?jtypeijmet&vtype=6&itype=9

### VI Brick Thermal Management

APPLICATION NOTE AN:200 VI Brick Thermal Management Contents Page Overview 1 Efficiency and Dissipated Power 1 Radiation 2 Conduction 2 Convection 4 Free Convection 4 Forced Convection 6 Definitions 8

### FREESTUDY HEAT TRANSFER TUTORIAL 3 ADVANCED STUDIES

FREESTUDY HEAT TRANSFER TUTORIAL ADVANCED STUDIES This is the third tutorial in the series on heat transfer and covers some of the advanced theory of convection. The tutorials are designed to bring the

### Theoretical and Numerical Analysis of Heat Transfer in Pipeline System

APCOM & ISCM -4 th December, 20, Singapore Theoretical and Numerical Analysis of Heat Transfer in Pipeline System Xiaowei Zhu, Hui Tang, *Hua Li, Jiahua Hong, Songyuan Yang School of Mechanical & Aerospace

### New Methods of Testing PCB Traces Capacity and Fusing

New Methods of Testing PCB Traces Capacity and Fusing Norocel Codreanu, Radu Bunea, and Paul Svasta Politehnica University of Bucharest, Center for Technological Electronics and Interconnection Techniques,

### Once you know the volume of air and the static pressure of the system to be cooled, you can determine the fan specifications for your product.

COOLING FAN REQUIREMENTS CALCULATIONS Determining System Impedance Determining the actual airflow produced by a fan mounted in an enclosure is much more difficult than calculating the airflow required.

### USE OF FLOW NETWORK MODELING (FNM) FOR THE DESIGN OF AIR-COOLED SERVERS

USE OF FLOW NETWORK MODELING (FNM) FOR THE DESIGN OF AIR-COOLED SERVERS Robin Steinbrecher Intel Corporation 2800 Center Drive Dupont, WA 98327 robin.steinbrecher@intel.com Amir Radmehr, Kanchan M. Kelkar,

### Everline Module Application Note: Round LED Module Thermal Management

Everline Module Application Note: Round LED Module Thermal Management PURPOSE: Use of proper thermal management is a critical element of Light Emitting Diode (LED) system design. The LED temperature directly

### Automotive MOSFETs in Linear Applications: Thermal Instability

Application Note, V1.0, May 2005 Automotive MOSFETs in Linear Applications: Thermal Instability by Peter H. Wilson Automotive Power N e v e r s t o p t h i n k i n g. - 1 - Table of Content 1. Introduction...

### Optimum proportions for the design of suspension bridge

Journal of Civil Engineering (IEB), 34 (1) (26) 1-14 Optimum proportions for the design of suspension bridge Tanvir Manzur and Alamgir Habib Department of Civil Engineering Bangladesh University of Engineering

### Navier-Stokes Equation Solved in Comsol 4.1. Copyright Bruce A. Finlayson, 2010 See also Introduction to Chemical Engineering Computing, Wiley (2006).

Introduction to Chemical Engineering Computing Copyright, Bruce A. Finlayson, 2004 1 Navier-Stokes Equation Solved in Comsol 4.1. Copyright Bruce A. Finlayson, 2010 See also Introduction to Chemical Engineering

### Notes on Polymer Rheology Outline

1 Why is rheology important? Examples of its importance Summary of important variables Description of the flow equations Flow regimes - laminar vs. turbulent - Reynolds number - definition of viscosity

### Experiment # 3: Pipe Flow

ME 05 Mechanical Engineering Lab Page ME 05 Mechanical Engineering Laboratory Spring Quarter 00 Experiment # 3: Pipe Flow Objectives: a) Calibrate a pressure transducer and two different flowmeters (paddlewheel

### HWR 431 / 531 HYDROGEOLOGY LAB SECTION LABORATORY 2 DARCY S LAW

HWR 431 / 531 HYDROGEOLOGY LAB SECTION LABORATORY 2 DARCY S LAW Introduction In 1856, Henry Darcy, a French hydraulic engineer, published a report in which he described a series of experiments he had performed

### Undergraduate Turbomachine Design Using CFD and 3-D Printing

Undergraduate Turbomachine Design Using CFD and 3-D Printing John Abbitt University of Florida Abstract For the past year, Mechanical & Aerospace Engineering students at the University of Florida have

### Practice 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 =

### Local improvement of flow and noise performances of axial-flow fans in a household refrigerator

Local improvement of flow and noise performances of axial-flow fans in a household refrigerator Seong-hun Kim, Seung Heo, Cheolung Cheong Pusan National University, Republic of Korea Taehoon kim LG Electronics,

### International Journal of ChemTech Research CODEN (USA): IJCRGG ISSN: 0974-4290 Vol.7, No.6, pp 2580-2587, 2014-2015

International Journal of ChemTech Research CODEN (USA): IJCRGG ISSN: 0974-4290 Vol.7, No.6, pp 2580-2587, 2014-2015 Performance Analysis of Heat Transfer and Effectiveness on Laminar Flow with Effect of

### NUMERICAL 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

### Hydraulic losses in pipes

Hydraulic losses in pipes Henryk Kudela Contents 1 Viscous flows in pipes 1 1.1 Moody Chart.................................... 2 1.2 Types of Fluid Flow Problems........................... 5 1.3 Minor

### Differential 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

### For Water to Move a driving force is needed

RECALL FIRST CLASS: Q K Head Difference Area Distance between Heads Q 0.01 cm 0.19 m 6cm 0.75cm 1 liter 86400sec 1.17 liter ~ 1 liter sec 0.63 m 1000cm 3 day day day constant head 0.4 m 0.1 m FINE SAND

### Review of Heat Transfer Parameters of Serrated Plate Fin Heat Exchanger for Different Materials

Review of Heat Transfer Parameters of Serrated Plate Fin Heat Exchanger for Different Materials Mr. S.V. Jagtap Prof. A.M. Patil Prof. H.M.Dange Abstract The heat transfer and flow friction characteristics

### Abstract. Key words: Intl. Journal of Microcircuits and Electronic Packaging

A Comparison of Fin Geometries for Heatsinks in Laminar Forced Convection: Part I - Round, Elliptical, and Plate Fins in Staggered and In-Line Configurations Denpong Soodphakdee, Masud Behnia, and David

### A Simplified 3d Model Approach in Constructing the Plain Vane Profile of A Radial Type Submersible Pump Impeller

Research Journal of Engineering Sciences ISSN 2278 9472 A Simplified 3d Model Approach in Constructing the Plain Vane Profile of A Radial Type Submersible Pump Impeller Abstract Gundale V.A. 1, Joshi G.R.

### All-Micromachined Joule-Thomson Cold Stage

All-Micromachined Joule-Thomson Cold Stage P.P.P.M. Lerou, G.C.F. Venhorst, T.T. Veenstra, H.V. Jansen, J.F. Burger, H.J. Holland, H.J.M. ter Brake, and H. Rogalla University of Twente The Netherlands

### INTERNATIONAL JOURNAL OF RESEARCH IN AERONAUTICAL AND MECHANICAL ENGINEERING

ISSN (ONLINE): 2321-3051 INTERNATIONAL JOURNAL OF RESEARCH IN AERONAUTICAL AND MECHANICAL ENGINEERING Study of forced convection heat transfer With DAQ & ANSYS First Authors Moopanar karthikeyan 1, Raote

### Optimization of electronic devices placement on printed circuit board

Optimization of electronic devices placement on printed circuit board Abstract by M. Felczak, T.Wajman and B. Więcek Technical University of Łódź, Wólczańska 211/215, 90-924 Łódź, Poland Power densities