This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Computational Study of Heat Transfer to the Walls of a DI Diesel Engine
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 11, 2005 by SAE International in United States
Annotation ability available
In this paper the heat transfer of the hot gases to the cylinder walls of DI Diesel engines is analyzed using Computational Fluid Dynamics (CFD) and compared to the predictions obtained with a zero-dimensional thermodynamic model based on a variant of the Woschni equation. The final objective is to improve the simple model by modifying the original equations to better take into account the influence of important parameters, such as swirl, on the heat transfer.
CFD calculations of the compression and expansion strokes have been made for two real DI Diesel engine geometries, a small one with a displacement of 0.4 l. and a heavy duty one of 2.0 l., and for different working points.
The total heat transfer rate to the cylinder surfaces is highly dependent on the mean flow behavior and turbulence levels. Hence, starting from initial conditions at Inlet Valve Closing (IVC), various parametric studies have been performed to take into account the influence on the heat transfer of the level of swirl on the one hand, of engine speed on another, and of modifying the clearance height on another.
Solutions obtained with both the CFD simulation and the diagnosis model are compared. They show that there are some important differences due to the assumptions made in the thermodynamic model concerning these parameters. Interesting conclusions are drawn from the more accurate CFD results and a simple modification of the terms included in the Woschni-like equation of the thermodynamic model is proposed to better take into account the significant influence of the swirl on the heat transfer.
CitationPayri, F., Margot, X., Gil, A., and Martin, J., "Computational Study of Heat Transfer to the Walls of a DI Diesel Engine," SAE Technical Paper 2005-01-0210, 2005, https://doi.org/10.4271/2005-01-0210.
- Higgins B. Siebers D. Aradi A. “Diesel-Spray ignition and premixed-burn behavior” SAE Paper 2000-01-0940 2000
- Kobori S. Kamimoto T. Aradi A. “A study of ignition delay of diesel fuel sprays” Int. J. Engine Research 1 o 1 29 39 2000
- Flynn P. F. Durret R. P. Hunter G. L. zur Loye A. O. Akinyemi O. C. Dec J. E. WestBrook Ch. K. “Diesel combustion: An integrated view combining laser diagnostics, chemical kinetics and empirical validation” SAE Paper 1999-01-0509 1999
- Benajes J. Molina S. Riesco J. M. Novella R. “Enhancement of the pre-mixed combustion in HD Diesel engines by adjusting injection conditions ” Thermo- and Fluid Dynamic Processes in Diesel Engines Congress 2004 511 525 2004
- Hampson G. J. Reitz R. D. “Two-color imaging of in-cylinder soot concentration and temperature in a heavy-duty DI Diesel engine with comparison to multidimensional modeling for single and split injections” SAE Paper 980524 1998
- Woschni G. “A universally applicable equation for the instantaneous heat transfer coefficient in the internal combustion engine” SAE 670931 1967
- Woschni G. “Die Berechnung der Wandverluste und der thermischen Belastung der Bauteile von Dieselmotoren” 491 499 1970
- Lapuerta M. Armas O. Molina S. “Study of the compression cycle of a reciprocating engine through the polytropic coefficient” Applied thermal engineering 23 2003 313 323 2003
- Tinaut F. “Contribución al estudio del proceso de combustión en motores de encendido por compresión de inyección directa” Universidad Politécnica de Valencia 1986
- Armas O. “Diagnóstico experimental del proceso de combustión en motores Diesel de inyección directa ” Universidad Politécnica de Valencia 1998
- Versteeg H. K Malalasekera W. “An introduction to Computational Fluid Dynamics. The Finite Volume Method” LongMan Scientific & Technical 1995
- Fluent 6 user's guide Fluent Incorporated 2001
- Patankar V. S. “Numerical heat transfer and fluid flow” Hemisphere Publishing Corp. Washington 1980
- Issa, R. I. “Solution of the implicit discretised fluid flow equations by operator-splitting” J. Comp. Phys 62 40 65 1986
- Gil A. “Caracterización del flujo de aire en el cilindro de motores Diesel DI mediante cálculo tridimensional” Universidad Politécnica de Valencia 2003
- Pastor J. V. Margot X. Gil A. Donayre J. C. “A methodology to estimate the swirl number at TDC in DI Diesel engines: through the combination of CFD and steady flow rig results” SAE paper 2004-01-1876 2004
- Tippelmann G. “A new method of investigation of swirl ports” SAE Paper 770405 1977
- Margot X. Gil A. Pastor J. M. Donayre C. “Cálculo tridimensional del flujo en el cilindro de un motor Diesel de inyección directa con conductos de admisión de torbellino variable” XV Congreso de Ingeniería Mecánica Cádiz 2002
- Payri F. Benajes J. Margot X. Gil A. “CFD modelling of the in-cylinder flow in direct injection Diesel engines” Computers & Fluids 33 995 1021 2004