A Comparative Analysis of In-Cylinder Flow, Heat Transfer and Turbulence Characteristics in Different Type Combustion Chamber

Öz

Recently some studies have been carried out on combustion chamber design for diesel and gasoline engines; however, they routinely used piston bowl model approach, which may neglect interactions with cylinder head design. Fluid motion within the cylinder of internal combustion engines has a significantly influence on the combustion process and engine efficiency. The aim of this study two different geometries of the combustion chamber of internal combustion engine were compared in terms of in cylinder flow and heat transfer during the intake process. For this, complete calculations of the intake stroke were performed under realistic operating conditions and heat transfer, velocity and turbulence flow fields obtained in each combustion chamber investigation detail. They were solved with finite volume method and ANSYS-Fluent 12.0 commercial code. The findings include using k-ε turbulence model and dynamic mesh generation model for different crank angle. The result of studies show that flow structure and turbulence intensity are affected on combustion chamber geometries. Also, the pent-roof type combustion chamber configuration was found to generate turbulence intensity more efficiently than the conventional type combustion chamber.

Anahtar Kelimeler

• Turbulence Intensity,Combustion Chamber,Dynamic mesh model,CFD

Kaynakça

1. Gold M. R., Arcoumanis C., Whitelaw J. H., “Mixture preparation strategies in an optical four valve port-injected gasoline engine”, Int. J. Engine Research, 1, 41-56, 2000.
2. Song J., Yao C., Liu Y., Jiang Z., Investigation on flow field in simplified piston bowls for DI diesel engine, Eng. Appl. Comp. Fluid Mech., 2, 354-365, 2008.
3. Varol Y., Oztop H. F., Firat M., Koca A., CFD modeling of heat transfer and fluid flow inside a pent-roof type combustion chamber using dynamic model, Int. Comm. Heat Mass Trans., 37, 1366-1375, 2010.
4. Jemni M. A., Kantchev G., Abid M. S., Influence of intake manifold design on in-cylinder flow and engine performances in a bus diesel engine converted to LPG gas fuelled, using CFD analyses and experimental investigations, Energy, 36, 2701-2715, 2011.
5. Keskinen J.P., Vuorinen V., Kaario O., Larmi M., Large eddy simulation of a piston–cylinder assembly: The sensitivity of the in-cylinder flow field for residual intake and in-cylinder velocity structures, Computers and Fluids 122, 123–135, 2015.
6. Fajardo C., Sick V., Flow field assessment in a fired spray-guided spark-ignition direct injection engine based on UV particle image velocimetry with sub crank angle resolution, Proc. Comb. Institute, 31, 3023-3031, 2007.
7. Kang K. Y., Reitz R. D., The effect of intake valve alignment on swirl generation in a DI diesel engine, Exp. Ther.Fluid Sci., 20, 94-103, 1999.
8. Egerman J., Koebcke W., Ipp W., Leipertz A., Investigation of the mixture formation inside a gasoline direct injection engine by means of linear raman spectroscopy, Proc. Comb. Institute, 28, 1145-1152, 2000.

9. Wu C., Deng K., Wang Z., The effect of combustion chamber shape on cylinder flow and lean combustion process in a large bore spark-ignition CNG engine, Journal of the Energy Institute, 89, 240-247, 2016.
10. Müller S. H. R., Böhm B., Gleibner M., Grzeszik R., Arndt S., Dreizler A., Flow field measurements in an optical accessible, direct injection spray-guided internal combustion engine using high-speed PIV, Exp. Fluids, 48, 281-290, 2010.
11. Stanfield P., Wigley G., Justham T., Catto J., Pitcher G., PIV analysis of in-cylinder flow structures over range of realistic engine speeds, Exp. Fluids, 43, 135-146, 2007.
12. Kang K. Y., Baek J. H., Turbulence characteristics of tumble flow in a four-valve engine, Exp. Ther. Fluid Sci., 18, 231-243,1998.
13. Basha S. A., Gopal K. R., In-cylinder fluid flow, turbulence and spray models-A review, Ren. Sust. Energy Reviews, 13, 1620-1627, 2009.
14. Payri F., Benajes J., Margot X., Gil A., CFD modeling of the in-cylinder flow in direct-injection diesel engine, Computer & Fluids, 33, 995-1021, 2004.
15. Johan Z., Moraes A. C. M., Buell J. C., Ferencz R. M., In cylinder cold flow simulation using a finite element method, Comp. Methods Appl. Mech. Eng., 190, 3069-3080, 2001.
16. Banaeizadeh A., Afshari A., Schock H., Jaberi F., Large-eddy simulations of turbulent flows in internal combustion engines, Int. J. Heat Mass Trans., 60, 781–796, 2013.
17. Bilgin A., Numerical Simulation of the cold flow in an axisymmetric non-compressing engine-like geometry, Int. J. Energy Res., 23, 899-908, 1999.
18. Mohammadi A., Yaghoubi M., Estimation of instantaneous local heat transfer coefficient in spark-ignition engines, Int. J. Thermal Sci., 49, 1309-1317, 2010.
19. Launder B.E., Spalding D.B., Lectures in Mathematical Models of Turbulence, Academic Press, London, 1972.
20. Heywood J. B. , Internal Combustion Engine Fundamentals, McGraw-Hill, 1998.
21. ANSYS-Fluent 12.0, User Guide, 2009.
22. Patankar S. V., Numerical heat transfer and fluid flow, Hemisphere, New York, 1980.
23. M. Firat, Modeling of fluid flow and heat transfer in new generation combustion chambers, MSc Thesis, Firat University, Inst. Science Graduate School Natural Applied Sciences, 2010.