Multidimensional simulation of the air-flow and fuel transport process in the air-assisted injection system of a new,low-emission two-stroke engine

Abstract

The aim of this work is to model the air and fuel flow process in the air-assisted injection system of a new, low emission two-stroke engine with a view to determine the critical features in the system that influence the engine performance. A computational method for multidimensional, compressible, two-phase flow using a Lagrangian-Eulerian approach is developed and used for this analysis. Good agreement is observed between computations and measurements of fuel consumption and pressure recovery in the injection system of the current prototype. The results show a strong dependence of the typical air flow characteristics of the injection system on engine speed. Significant fuelling after inlet port closure, higher fuel transport efficiency at low speeds and a substantial impingement of liquid fuel on the solid walls of the injection system are also evident from the results of the computations. This suggests a delayed transient response and strong speed dependence of the quality of mixture preparation in this system, which explains certain observed trends in the current prototype of the engine.

Keywords

air-assisted injection system two-stroke engine Lagrangian-Eulerian approach fuel transport

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References

Kenny

R. G.

Developments in two-stroke cycle engine exhaust emissions

Proc. Instn. Mech. Engrs, Part D: J. Automobile Engineering, 1992, 26 (2), 93–106.

Saxena

Mathur

H. B.

Radzimirski

Reduction of fresh charge losses by selective exhaust gas recirculation (SEGR) in two-stroke engines. SAE paper 891806, 1989.

Plohberger

Landfahrer

Mikwlic

Development of a fuel injected two-stroke gasoline engine. In International Congress and Exposition, Detroit, Michigan, March 1988, SAE paper 880170.

Vieilledent

Low pressure fuel injection system for two stroke engines. SAE paper 780767, 1978.

Landfahrer

Plohberger

Alten

Mikwlic

A thermodynamic analysis and optimization of two stroke gasoline engines. In International Congress and Exposition, Detroit, Michigan, February 1989, SAE paper 890415.

Narasimhan

M. V.

Raman

Venkataraman

M. K.

Fuel efficient and low emission two stroke gasoline engine. In SERC, Research Highlights, January 2000 (Department of Science and Technology, India).

Bakshi

Ravikrishna

R. V.

Modeling the air-assisted injection system of a new, low-emission two-stroke engine. In International Congress and Exposition, Detroit, Michigan, March 2002, SAE paper 2002–01-0904.

Gosman

A. D.

Johns

J. R.

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

Doormal

J. P.V.

Raithby

G. D.

Enhancements of a SIMPLE method for predicting incompressible fluid flows

Numer. Heat Transfer, 1984, 7, 147–163.

10.

Wilcox

D. C.

Turbulence Modeling for CFD, 1993 (DCW Industries).

11.

Crowe

Sommerfeld

Tsuji

Multiphase Flows with Droplets and Particles, 1998 (CRC Press, Boca Raton, Florida).

12.

Reitz

R. D.

Modeling atomization process in high-pressure vaporizing sprays

Atomisation Spray Technol., 1987, 3, 309–337.

13.

Liu

A. B.

Mather

Reitz

R. D.

Modeling the effect of droplet drag on breakup of fuel sprays. SAE paper 930072, 1993.

14.

White

F. M.

Fluid Mechanics, 1999 (McGraw-Hill, New York).

15.

Heywood

J. B.

Internal Combustion Engine Fundamentals, 1988 (McGraw-Hill, New York).

16.

Ferziger

J. H.

Peric

Computational Methods for Fluid Dynamics, 1997 (Springer, Berlin).

17.

Naber

J. D.

Reitz

R. D.

Modeling of engine spray/wall impingement. SAE paper 880107, 1988, pp. 1–23.