Numerical simulation of the multiphase flow phenomena in the crankcase of an internal combustion engine

Abstract

The flow processes in the crankcase of an internal combustion engine are essential for many sub areas of a combustion engine. Piston cooling, oil transport through the main and conrod bearings or the tribology of the piston assembly are some of them and take place in the crankcase. The oil supply of the liner plays an important role for the friction losses of an engine. Additionally oil aerosols are emerging in the crankcase. The sizes of the droplets are crucial for the oil separator dimensioning. Due to blow-by a part of the crankcase gas flows back to the intake manifold (via the oil separator) and the containing oil in the flow is responsible for additional emissions of the engine.

This study introduces a simulation method for the calculation of the multiphase flow phenomena in the crankcase of a four-cylinder diesel engine. All relevant effects have been identified and modeled numerically. The detailed geometry of the crankcase volume and all moving parts of the piston assembly have been considered in the model. To calculate the multiphase flow in the crankcase a discrete particle method has been chosen, where the gas flow is described continuously and the oil flow is modeled with the discrete droplet method. With this method the oil flow and the interaction with the gas flow can be calculated. The computational fluid dynamics results enable new insights into the crankcase flow of an internal combustion engine and therefore statements about the oil distribution in the crankcase can be made. That leads to further knowledge of the transport processes in the crankcase.

Keywords

Crankcase flow multiphase flow computational fluid dynamics oil transport diesel engine

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References

Cunningham

Kee

. CFD prediction of crankcase flow regimes in a crankcase scavenged two-stroke engine. SAE Technical Paper 970361, 1997.

Deighan

Zuhdi

. Crankcase flow modeling for a racing motorcycle engine. SAE Technical Paper 2007-01-0266, 2007.

Ranganathan

. Engine crankcase Pumping flow model. SAE Technical Paper 99-01-0215, 1999.

Edelbauer

. Numerical simulation of the lubricating oil and air flows in the crankcase of an internal combustion engine. PhD Thesis, Technische Universität Graz, Graz, Austria, 2007.

Friedrich

Künsberg-Sarre

et al . Influence of the crankcase flow on the friction torque using the example of the BMW boxer engine. ATZ/MTZ. In: Virtual powertrain creation, Unterschleissheim/München, 30 November 2010-1 December 2010, pp. 1–18. Berlin: Springer.

Johnson

. Experimental analysis of crankcase oil aerosol generation and control. PhD Thesis, Loughborough University, UK, 2012.

Ferziger

Perić

. Computational methods for fluid dynamics. Berlin: Springer, 2002.

Durbin

. Near-wall turbulence closure modelling without damping functions. Theor Comp Fluid Dyn 1991; 3: 1–13. doi:10.1007/BF00271513.

Popovac

Hanjalic

. Compound wall treatment for RANS computation of complex turbulent flows and heat transfer. Flow Turbul Combust 2007; 78: 177–202.

10.

Faeth

. Recent advances in modeling particle transport properties and dispersion in turbulent flows. In: JSME thermal engineering joint conference proceedings, 1983; 2: 517–534.

11.

Gosman

Johns

. Computer analysis of fuel-air mixing in direct-injection engines. SAE Technical Paper 800091, 1980.

12.

Ishii

Hibiki

. Thermo-fluid dynamics of two-phase flow. New York: Springer, 2011.

13.

Nordin

. Complex chemistry modeling of diesel spray combustion. PhD Thesis, Chalmers University of Technology, Sweden, 2001.

14.

Thirouard

. Characterization and modeling of the fundamental aspects of oil transport in the piston ring pack of internal combustion engines. PhD Thesis, MIT, USA, 2001.

15.

Sauter

Trautmann

. Messung und Abscheidung von Ölnebelaerosolen aus der Kurbelgehäuseentlüftung. In: MTZ Motorentechnische Zeitung, 2000; 61: 874. doi:10.1007/BF03255052

16.

Agarwal

Varghese

. Numerical investigations of piston cooling using oil jet in heavy duty diesel engines. Int J Eng Res 2006; 7: 411–421.

17.

Creaven

Fleck

et al . Laser Doppler velocimetry measurements of flow within the cylinder of a motored two-stroke cycle engine - comparison with some computational fluid dynamics predictions. Int J Eng Res 2003; 4: 103–128.

18.

Friedrich

Künsberg-Sarre

et al . Crankcase flow of a 4 cylinder in-line ICE. In: AVL AST user conference, 2011; 1–14. Graz. 28 June 2010 – 30 June 2010.