Gas Flow into Rotary Valve Intake and Exhaust Mechanism in Internal Combustion Engine

Transcription

1 World Academy of Science, Engineering and Tecnology International Journal of Mecanical, Aerospace, Industrial, Mecatronic and Manufacturing Engineering Vol:7, No:4, 13 Gas Flow into Rotary Valve Intake and Exaust Mecanism in Internal Combustion Engine R. Usubamatov, Z. A. Rasid International Science Index, Mecanical and Mecatronics Engineering Vol:7, No:4, 13 waset.org/publication/ Abstract Simple design of a rotary valve system is capable of controlling intake and exaust gases, wic will eliminate te need of known complex mecanisms. Te cost of material and production, maintenance, and noise level of te system can be furter reduced. Te new mecanism enables te elimination of te overlapping of valves work tat reduces gas leakage. Tis paper examines teoretically te gas flow troug te oles of a rotary valve design in a small engine. Preliminary results sow tat te new gas flow as many positive differences tan a conventional poppet-valve system. New dependencies on te gas speed enable te finding of better solutions for te geometry of a rotary valve system tat will result in a iger efficiency of an internalcombustion engine of te automotive industry. T Keywords Gas arrangement, internal combustion engine. I. INTRODUCTION HE conventional gas intake and exaust mecanism tat is based on te camsaft poppet valve system comprises of many moving parts and as many deficiencies like ig production costs, ig component wear, noisy operation and lower performance efficiency [1], []. Apart from tese deficiencies wic are due to camsaft design peculiarities, tere is te ig gas flow rate into oles of te valves and overlap period wen te exaust and intake valves are bot open at te same time [3], [4]. Tis situation creates a number of flow effects tat reduce te part load performance, reduces te volumetric efficiency resulting in unstable combustion, and reduces te engine efficiency [5] [7]. Tis is te reason tat tere are many publications dedicated to modeling of te internal-combustion engine intake-exaust system [8]-[1]. To replace te just mentioned components are te rotary valves, wic rotate in teir ousings tat are fitted to te cylinder-ead. Te rotary valves systems of te internal combustion engines are not new. Tere are companies tat produce rotary valves eads [11], but tere are not so muc publications and results of investigation one, but tere are not so muc publications and results of investigation one [1]. Rotary valves run directly by te cranksaft via te cain mecanism. Eac rotary valve incorporates a ole or window wic controls te opening and closing of te intake or exaust passage during its rotational motion. Te opening and closing effects from te rotational motion of te buses are timed precisely as to work in conjunction wit te gas flow requirements of an internal-combustion engine. At tis point, simple sketc of te new system and some preliminary studies on te fluid dynamics of te flow ave been carried out (Fig. 1). Oter studies like an exaust gas motion, temperature and pressure R. Usubamatov is wit te University Malaysia Perlis, Malaysia, (pone: ; fax: ryspek@unimap.edu.my). Z. A. Rasid is wit te University Malaysia Perlis, Malaysia, (fax: ; zulkifli_rasid@unimap.edu.my). of combustion gas are very important and need for te Computational Fluid Dynamics metods [13]. Real results of work in suc a mecanism will ave some differences due to mentioned assumptions. Te scope of tis paper is a presentation of principle of te new design work and availability of use for engines. Te objective of tis new design of a gas intake and exaust valve arrangement in an internal-combustion engine is to decrease and eliminate all work deficiencies in te existing mecanisms [14]. Tis new design provides a gas intake and exaust system tat is more long-lasting and reliable, tecnologically simpler to produce, igly stable ermetically, less wearing of surface elements, less gas leakage ence a more complete combustion is possible resulting in less environmental pollution. Tis new design does not require ig-level of maintenance and ceaper as compared to te former design. Tis new intake and exaust system is ceaper and can be introduced to all kinds and types of internal-combustion engine designs suc as in cars, tracks, lorries, motorcycles, sips, boats, tractors, etc [15]. II. BRIEF DESCRIPTION OF THE WORK OF ROTARY VALVE MECHANISM Fig. 1 sows a sketc of an idealized model of a rotary valve system in te internal-combustion engine. Te rotary valve assembly includes te intake and exaust ousing block. Te intake and exaust bus rotates freely like sliding bearings witin te ousing block. Te intake and exaust bus comprises one intake-exaust ole in te combustion camber. A passage of intake-exaust oles is separated and located around te circumference of te intake-exaust bus, wic are aligned wit te gas passage at different angles of rotation according to te angular crank positions of te cranksaft. Te motion of te piston is kinematical matced wit te rotary motions of te intake-exaust bus. At te beginning of te gas intake process, te two side of te bus intake ole is aligned and connected wit te intake ole of te carburetor and wit te front intake-exaust port of te combustion camber. Fuel gas begins to run troug te passage and into te cylinder. Wen te engine piston reaces te lowest point, te two sides of te bus intake ole passes, i.e., te intake ole of te carburetor and te front intake-exaust port, and te cylindrical surface of te bus closed te carburetor ole and front ousing port. According to te engine cycle, after te combustion stage, te engine piston in te cylinder puses te combusted gases from te front exaust bus ole troug te outlet ole and into te atmospere. Wen te engine piston reaces te igest level, te rotating front bus exaust ole passes te front ousing port and te cylindrical surface of te intakeexaust bus closes te front ousing port. International Scolarly and Scientific Researc & Innovation 7(4) scolar.waset.org/1999.8/999757

2 World Academy of Science, Engineering and Tecnology International Journal of Mecanical, Aerospace, Industrial, Mecatronic and Manufacturing Engineering Vol:7, No:4, 13 radius, α is an angular location of te crank-saft (Fig. 1). Te actual mass flow rate and isentropic mass flow rate troug a valve are given by te s [13] Q C d Q is Q is ρ v A v is (1) International Science Index, Mecanical and Mecatronics Engineering Vol:7, No:4, 13 waset.org/publication/ Fig. 1 Gas intake and exaust in rotating valve Gas leakage and sealing problems are a few of te areas tat may need a careful attention. In fact, tere are a few oter areas tat need a careful attention suc as eat transfer and gas flow caracteristics and beavior of tis new intake and exaust system. However, at tis stage, te focus is more into te kinematics and workability of te system. Te problems suc as sealing and eat transfer will be dealt wit at te later stage of tis researc. Tere may be modifications to te design of te system in order to eliminate te problems tat may arise. III. ANALYTICAL APPROACH In tis preliminary analytical study of te new system, air viscosity and pressure are assumed to remain constant (incompressible flow) trougout te system. Tis approac is normal for preliminary considerations as tat mentioned in muc researc focuses []. Tis paper considers flow rate as incompressible flow for simplicity of analysis. In future researc, te gas flow rate will be presented by a metod of Computational Fluid Mecanics were all variable parameters suc as viscosity, pressure and temperature will be analyzed. It is known tat te most significant airflow restriction in an internal-combustion engine is te flow troug te intake and exaust valves. Te minimum cross-sectional area in te intake-exaust system is at te rotary valve. Te modeling of te gas flow troug te valve and defining te boundary conditions of te gas flow can assist in te successful application of te new valve design. Intake-exaust valve rotations can be presented as a function of te cranksaft rotation of te internal-combustion engine. Te interdependence between te angular motion of te rotary valve and angular motion of te cranksaft are presented by te following. Te angular velocity of te cranksaft as te expression ω c πn, (n rev/min), and te tangential velocity of te end of crank is v R ω c, ten te linear velocity of a piston is presented by v p Rω c sinα, were R is te crank-saft were C d is a valve discarge flow coefficient (ratio of an effective flow area A to a representative area A max ), v is is te reference isentropic velocity, A and ρ v are te cross sectional area and fluid density at te valve, respectively. Te gas flow rate into te cylinder as te following expression Q c (πd /4)v p, were D is te diameter of te bore; v p v t sinα; v t R*ω c πrn is te tangential velocity of te end of te cranksaft; R is te cranksaft radius; n is te number of revolutions of a cranksaft. Te gas flow rate into te ole of te valve as te following expression Q v A v, were A is te area of te opening of te valve ole. A is calculated from Fig. 1. Te continuity principle of flow rate gives te formula Av c Av v because te gas flow rate into te cylinder, and into te ole of te valve is te same. Ten after substitutions and transformation, te gas speed into te ole of te valve as te following expression πd πd V R(πn)sinα Rπnsinα () 4A A According to te kinematical ratio of te valve and cranksaft rotations, te angular speed ω v of te valve rotation is twice less tan tat of te angular speed ω c of a crank rotation. Subsequently, ω v (1/) ω c or β(t) α(t)/ or β α/, were β is te angular coordinate of te rotating valve (Fig. 1). Equation (1) is for an isentropic flow from an upstream reservoir to a minimum valve troat area, A f. In te idealized model of a rotary valve sown in Fig. 1, tere is an evident possibility of a variable minimum area, A f Te variable opening of te rectangular area for te intake valve ole (Fig. 1) is presented in te geometrical form by te following expression a *( d / )*πβ adαπ A ac (3) 36 7 were a is te lengt of te valve ole and d is te diameter of te rotary valve, d βπ d απ c is te widt of te variable slit between te rotary valve and te inlet port of te cylinder. Te maximum area, A max can be expressed by te following after te substitution of α 9 into (3) adπ A max ab 8 Equation (1) assumes an isentropic flow from te upstream reservoir to a minimum troat valve area, A. In te idealized model of te rotary valve sown, te variable area of te valve is canged from te minimum, A to (4) International Scolarly and Scientific Researc & Innovation 7(4) scolar.waset.org/1999.8/999757

3 International Science Index, Mecanical and Mecatronics Engineering Vol:7, No:4, 13 waset.org/publication/ World Academy of Science, Engineering and Tecnology International Journal of Mecanical, Aerospace, Industrial, Mecatronic and Manufacturing Engineering Vol:7, No:4, 13 maximum, A max ab tat is equal to te area of te cylinder port size (Fig. 1). A discarge flow coefficient is expressed by te C d A A adαπ α max 7 ( adπ / 8 ) 9 Te discarge flow coefficient, C d for te rotary valve varies according to te angle, β of rotation of te valve or angle, α of rotation of te cranksaft. Te flow coefficient increases monotonically from zero and furter increases wit te turn of te valve since te effective area troug te valve increases wit te turn, wile te representative area ab is constant. Te maximum value of C d 1. wen α 9. Te cange of te discarge flow coefficient C d is illustrated in Fig.. Fig. Discarge flow coefficient vs. turn of rotary valve It is known tat te discarge flow coefficient, C d is not a strong function of te turn of te valve wen te gas passes te small area of te valve slit and results for te valves work []. At tis condition, te coefficient, C d sould be defined experimentally and calculated by Reynolds number because te inlet gas jet is attaced to bot te rotary valve and te inlet port, and tereby affected by viscous sear. Wen te inlet area is sufficiently large, te flow coefficient is independent of te Reynolds number. Te rotary valve design provides also for te sape of te intake ole. From a constructive point of view, it is preferable to design a rectangular valve ole and from tecnological point of view, it is preferable to ave circular parts for te opposite sides of te rectangular ole. For te rectangular form of te intake port, te ratio of te widt, b to lengt, a is k b/a. Te optimal ratio, k sould be defined based on te calculation of optimal termodynamics regimes of te rotary valve work. Te rotary valve performance requires determining te effect of valve on an engine volumetric efficiency. Te volumetric efficiency at limiting case in wic te flow is always coked as te equation [5] (α ic α io ) ev.58, πz were α ic and α io are te angles at wic te intake valve closes and opens respectively, Z is te inlet Mac index (in average Z.6, γ 1.4 is te specific eat ratio). For te poppet valve system, te ratio (α ic α io )/π 1.3, due to reasons of te valves work overlapping. For te new rotary (5) valve system, tis ratio is equal to 1., and tus te volumetric efficiency will ave te following expression e v.58/z.97. After substituting te expressions of te variable area of te valve ole (3), te angular velocity, and te valve turn coordinate as a function of te cranksaft angle into (), te variable gas speed into te ole of te valve of an engine cylinder will ave te v 7 πd 36 πd Rnsinα Rπn sinα (6) adαπ adα Analysis of (6) sows tere is a maximum gas speed into te valve ole tat defined by te first derivative of (6) wit variable α gives dv, dα 36 πd 36 πd Rnsinα( ad) Rncosα( adα) After transformation and simplifications, te angle α of te valve rotation tat gives te maximum gas speed as te α tanα (7) Equation (7) is a transcendental equation were roots cannot be found analytically. Solutions of a transcendental equation can be found by using grapical metods. Te leftand side of te equation is expressed as a linear function wile te rigt-and side is a trigonometric function. Grapical solving of tis equation gives te result of te angle of te crank rotation, wic te maximum gas speed into te ole of te rotary valve will occur to be α 5 (Fig. 3). Fig. 3 Te angle of te crank rotation gives maximum gas speed into te valve ole After substitution, te equation of te maximum gas speed into te valve ole will ave te 36 πd Rnsin5 ad *5 19.7D Rn ad v max Te diagram of te gas speed into te ole area A of te rotary valve versus te angle α of a crank-saft is sown in Fig. 4. Tis diagram is based on (6) wen n 3rev/min (8) International Scolarly and Scientific Researc & Innovation 7(4) scolar.waset.org/1999.8/999757

4 World Academy of Science, Engineering and Tecnology International Journal of Mecanical, Aerospace, Industrial, Mecatronic and Manufacturing Engineering Vol:7, No:4, 13 dv, dα 36 πd Rn [(1/ )sinα {( α / ) + γ}cosα] ad After transformation and simplifications, te angle α of te valve rotation tat gives te maximum gas speed as te International Science Index, Mecanical and Mecatronics Engineering Vol:7, No:4, 13 waset.org/publication/ Fig. 4 Te gas speed into te valve ole versus te angle of te cranksaft rotation Valve ole area A is te dotted line for te ole sizes Tis diagram sows tat te maximum gas speed into te ole of valve occurs at te beginning of te ole opening of valve and at te end of te ole closing of valve. Te difference between maximum and minimum gas speed into te ole of te valve is around 35%. Te diagram sows tat result of te ig gas speed for te ig speed of te cranksaft rotation is far from te situation of te gas coking into te valve ole. Te rotary valve gives te lowest gas flow speed wen te piston is at a ig speed of motion. Te maximum gas speed into te ole of te rotary valve is also many times less tan te maximum gas speed into te ole of te poppet valve design. Te obtained results prove tat te new rotary valve system is acceptable and can perform proper work in internal-combustion engines at different regimes, including at te ig level of piston speeds. Te work of a known poppet valve system in internalcombustion engines sows tat a valve opening and closing time in relation to te cranksaft rotation is not perfect. Tere is quite a substantial amount of early opening of intake valve (-3 o ) and late opening of intake valve (4 o - 6 o ). Exaust valve opens early (4 o -6 o ) tat leads te ig pressure gases do not use for engine work. Te early opening of exaust valve also cut sort te working stroke of te engine. Some amount of te gas expansion pressure ΔP 15% in te working stroke is wasted by te early opening of te exaust valve. Intake valve closes late (4 o - 6 o ) leads to pusing fuel gases to carburetor []. Te early opening and closing of te valves certainly would reduce te efficiency and fuel economy of te engine. To avoid te ig gas speed penomena into te intake and exaust ole, it is possible to ave some early opening and late closing of tis ole by increasing te area of te ole into te ousing of te rotary valve. However suc trick as some positive and negative circumstances. Early opening of te ole for gas intake process can reduce te pick of te gas ig speed into te cannel of te rotary valve. For tis case (6) of te variable gas speed into te ole of te valve of an engine cylinder will ave te (β α/), 18 πd Rnsinα 18 πd Rnsinα v (9) ad( β + γ ) ad[( α / ) + γ ] were γ is te angle of earlier opening of te rotary valve. Equation (9) gives a maximum gas speed into te valve ole tat defined by te first derivative wit variable α gives α tanα - γ (1) Equation (1) is also a transcendental equation, were te solution is found by grapical metods. Grapical solving of tis equation gives te result of te angle of te crank rotation, wic te maximum gas speed into te ole of te rotary valve will occur (Fig. 5). Fig. 5 Te angle of te crank rotation gives maximum gas speed into te valve ole wit its earlier opening As mentioned earlier te maximum gas speed into te ole of te valve will occur at α 5. At tis moment, te rotary valve turned on β.5. If arrange early opening of te ole for gas flow process at tis angle, ten te gas speed into te valve ole versus te angle of te cranksaft rotation will ave te diagram tat presented on Fig. 6. Tis diagram is based on (9) wen n 3 rev/min. Fig. 6 Te gas speed into te valve ole wit early opening of te ole for gas flow (te rotary valve turned on β.5 ) vs. te angle of te cranksaft rotation Valve ole area A is te dotted line for te ole sizes Te maximum gas speed is calculated by (9), wen α 34 (defined grapically) and γ.5. Te variation of te maximum and minimum gas speed into te ole of te valve International Scolarly and Scientific Researc & Innovation 7(4) scolar.waset.org/1999.8/999757

5 International Science Index, Mecanical and Mecatronics Engineering Vol:7, No:4, 13 waset.org/publication/ World Academy of Science, Engineering and Tecnology International Journal of Mecanical, Aerospace, Industrial, Mecatronic and Manufacturing Engineering Vol:7, No:4, 13 is around %, and te pick of te gas speed does not ave te sarp form like in Fig. 6. Earlier opening and later closing of te ole of te rotary valve is accompanying wit te gas leakage. Te process of exaust of te burned fuel gives penetration of some volume of burned gas into te intake ole of te rotary valve and mix wit fres fuel gas. Te volume of te burned fuel wit te fres gas sould be small and does not influence on te wole content of te fres fuel gas tat intake to te cylinder. During gas exaust processes te piston is coming up to top level of te location and pusing out te burned fuel. At te location of te piston tat close to its top level, te remaining volume of burned fuel can be calculated by te W (πd /4) R(1 - cosα) (11) were all parameters presented in Fig. 1 After transformation of (11) te angular location of te crank saft α for earlier opening of te exaust ole will ave te 4W α arccos 1 (1) πd R Te minimum volume W of te burned fuel tat can be mixed wit fres gas fuel is calculated on a basis of te limit of its quality. Tere is some percentage limit of burned gases into te fres fuel gas tat does not reduce its quality. For te gas intake manifold, it is possible to decrease te gas speed until its minimum one. To avoid te ig speed gas into entry part of te intake cannel of te rotary valve tat connects te carburetor or injection manifold, it is recommended to make te widt e of te ole of te manifold wider ten widt of te intake cannel of te rotary valve (Fig. 1). Te quarter of te widt of te intake ole of te valve can be presented as te initial slit f between te intake manifold and te cannel of te rotary valve. Tis slit can be expressed by te angle of te rotation of te valve by te 36 * a / 4 9a β (13) πd πd Fig. 7 demonstrates te diagram of te gas speed into te manifold ole wit early opening of te valve ole for gas flow wen te rotary valve turned on te quarter of te ole (β 11.5 ). Tis diagram is based on (9) wen n 3rev/min. Fig. 7 Te gas speed into te manifold ole wit early opening of te valve ole for gas flow (te rotary valve is turned on, β 11.5 ) vs. te angle of te cranksaft rotation Valve ole area A is te dotted line for te ole sizes Te gas speed into te manifold ole of te rotary valve is increasing wit its rotation and reaces te maximum wit opening of te full area of te ole (Fig. 7). Te gas speed troug te ole of te rotary valve can be canged by varying te area of tis ole. It is possible to increase te area of te ole by increasing te lengt a, and te diameter, d of te rotary valve (b d/8), (6). Te optimal size of te ole of te rotary valve can be calculated on a basis of gas dynamics and oter parameters of a running internalcombustion engine. IV. A WORKING EXAMPLE It is given: D 7mm diameter of a bore, R 35mm a crank-saft radius, d 5mm diameter of a rotary valve, a 4mm lengt of te ole of rotary valve, b mm widt of te ole of rotary valve, n 3 rev/min rotary speed of te cranksaft. (v Rπn.35**π*3/6 11. m/s). In tese preliminary studies and calculations at tis stage, engine speed is taken to be at 3 rev/min. Tis speed is taken as average working speed for small engines. However, in later stage of researc, a variable of engine speed will be taken into consideration. Te maximum value of te gas speed into te valve ole is defined by substituting te given tecnical data into (8) 19.7D Rn 19.7 *.7 *.35 * (3 / 6) v 84.4m / s ad.4 *.5 Te obtained result proofs tat te new rotary valve system is acceptable and can perform proper work for internal-combustion engines at different regimes, including at ig piston speed levels. Te inlet area of te valve ole can be cecked based on te maximum gas speed witout te coked flow rate for wic te engine is designed []. Te maximum gas speed troug te inlet valve sould be less tan te sonic velocity at a condition were te intake flow is not coked. For te given tecnical data, te maximum gas speed, v 84.4 m/s is more tan four times less tan te sonic velocity, v s 33 m/s. Tis means te gas flow is not coked. Equation (8) can be used to give various possibilities of te area for an intake valve ole and can be used in calculations to obtain appropriate solutions. Te variable size of te area of te rotary valve ole can be cecked International Scolarly and Scientific Researc & Innovation 7(4) scolar.waset.org/1999.8/999757

6 International Science Index, Mecanical and Mecatronics Engineering Vol:7, No:4, 13 waset.org/publication/ World Academy of Science, Engineering and Tecnology International Journal of Mecanical, Aerospace, Industrial, Mecatronic and Manufacturing Engineering Vol:7, No:4, 13 based on te gas coking wen it is at te maximum speed (8) by te [5]. A 1.3D v sinα/v s were v s is te sonic velocity in te ot gas, v πrn. Te minimum area of te valve ole is calculated to be A 1.3*.7 * π*.35*(3/6)*sin5 / *1-5 m 18.5 mm. Te real size of te valve ole area (3) is απ 5 * π A f ad 7 7 4*5* mm Te real size of te ole area at te critical gas speed is more tan te minimum size of te ole area, A f A or > Tis means tere is no gas coking in te valve ole at maximum gas speed. Te volume of te burned gas wen te piston locates at te top position and in case of earlier opening of te intake ole tat reduces te gas speed is calculated by (1) wit α 5 W (πd /4)R(1 - cosα) (π7 /4)*35(1-cos5 ) 513 mm 3 Te piston puses out tis volume of te burned gas troug te two oles. One leads to te intake cannel, second to te exaust cannel. Te area of te variable valve ole of te exaust cannel is twice more tan te area of te variable valve ole of te intake cannel. It means tat only 1/3 of te burned gas volume W will go to te intake cannel of te valve. During te gas intake process, piston goes to dawn and 1/3 of te burned gas volume W from te exaust ole will go to te cylinder. Te total volume of te burned gases tat locate into te intake and exaust cannels and involved into filling of te cylinder will be /3 of te volume W. Te volume of te cylinder of te engine filled by te fres gas fuel is presented by te following W c (π7 /4)*35(1-cos18 ) 6939 mm 3 Te percentage of te burned gases into te fres fuel gas is presented by te following δ [(/3)W/(W c W)]*1% [(/3)513/( )]*1%.13% Tis component of te burned gas into te fres fuel gas does not play te role and te earlier opening of te rotary valve ole on te turned angle β.5 can be used for te design of te rotary valve. tat te new system is capable of increasing te efficiency of te gas intake and exaust mecanism performance and sow tat te speed of gas flow in te new system as many differences tan tat of te conventional camsaft-valve system. Te new mecanism enables te elimination of te overlapping of valves work, like early valves opening and late closing, wic leads to less gas leakage. Tese positive attributes of te new design will result in a iger efficiency of internal-combustion engines. ACKNOWLEDGMENT Fundamental Researc Grant Sceme of Ministry of Higer Education, Malaysia, funds tis researc project. REFERENCES [1] Ferguson C.R., Kirkpatrick A.T. (1). Internal Combustion Engine, nd ed. Jon Willey & Sons Inc. Hoboken NJ. [] Pulkrabek, W.W., (4). Engineering Fundamentals of te Internal Combustion Engine ( nd ed.). Pearson Prentice-Hall, New Jersey [3] Karagiorgis S., Collings N., Glover K.and Petridis T. (6). Dynamic Modelling of Combustion and Gas Excange Processes for Controlled Auto-Ignition Engines, Proceedings of te American Control Conference Minneapolis, Minnesota, 5t US Combustion Meeting, USA, pp [4] Harrison M.F., Stanev P.T., (4). Measuring wave dynamics in IC engine intake Systems, Journal of Sound and Vibration, 69, pp [5] Ganesan, V., (3). Internal Combustion Engine ( nd ed.). Tata McGraw-Hill, New Deli. [6] Piscaglia F., Ferrari G., (9). A novel 1D approac for te simulation of unsteady reacting flows in diesel exaust aftertreatment systems, Doi:1.116/j.energy.8.8. [7] Semin, R.A. Bakar, A.R. Ismail, (7). Air flow analysis of four stroke direct injection diesel engines based on air pressure input and L/D Ratio, J. Eng. App. Sci. (11), pp [8] Montenegro, A. Onorati. (9), Modeling of Silencers for I.C. Engine Intake and Exaust Systems by means of an integrated 1DmultiD Approac, SAE Int. J. Engines 1(1), pp [9] Ferrari G., Piscaglia F. (7). Modeling of te Unsteady Reacting Flows in te Diesel Exaust After Treatment Systems, ECOS Conference - Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, Padova (Italy). [1] Onorati, G. Ferrari, G. D'Errico, G. Montenegro, (). Te Prediction of 1D unsteady Flows in te Exaust System of a S.I. Engine Including Cemical Reactions in te Gas and Solid Pase, SAE Int. Congress & Exp. (Detroit, Micigan), paper No [11] Hunter M.C.I. Rotary Valve Engines, Jon Wiley, New York, [1] Cow P. H. P., Watson H. C. and Wallis T. (7). Combustion in a ig-speed rotary valve spark-ignition engine. Proceedings of te Institution of Mecanical Engineers, Part D: Journal of Automobile Engineering, Vol. 1 No. 8 pp [13] Douglas J. F., Gasiorek J.M., Swaffield J.A, and Lynne J.B., (5). Fluid Mecanics, Pearson Prentice Hall, 5 t. Ed. [14] Ismail, A.R., Semin, R.A., Bakar, (7). Valve Flow Discarge Coefficient Investigation for Intake and Exaust Port of Four Stroke Diesel Engines, J.Eng. App. Sci. (1): pp [15] Bauer, H., Jager, T., & Hutter, S.A. (eds.). (4). Gasoline- Engine Management: Gasoline Direct Injection ( nd ed). Robert Bosc GmbH, Suffolk UK. V. CONCLUSION Te rotary valve design of te intake and exaust flow system is capable of controlling te intake and exaust gases and sows better tecnical caracteristics of te cylinderead work. Gas flow in te new system is acceptable and gives good results. Gas fluid dynamic calculations indicate International Scolarly and Scientific Researc & Innovation 7(4) scolar.waset.org/1999.8/999757