Study of turbulence in a motored four-stroke internal combustion engine
- Carnegie-Mellon University, Pittsburgh, Pa.
- Technion - Israel Institute of Technology, Haifa, Israel
A theoretical-experimental study of a motored, reciprocating, four-stroke, internal combustion (IC) engine is presented. The experimental data were obtained by means of an LDV system, in a transparent cylinder using smoke as seeding material. The theoretical program solves the Navier-Stokes equations in cylindrical coordinates and two additional (k/epsilon) equations for turbulence. The theoretical-experimental results show that in the intake stroke a high-speed jet strikes the valve, is radially deflected along the cylinder head, and forms a recirculation zone with almost constant axial velocity behind the valve. Production of turbulence occurs at the shear layers of the incoming jet. In the compression and power strokes, the piston drives the flow and the velocity, and turbulent kinetic energy profiles become uniform. During the exhaust stroke, a high-speed outgoing jet is formed. Local generation of turbulence occurs at the shear layers of this jet and above the valve. Comparison between theory and experiment shows satisfactory agreement for the four strokes. The major reasons of disagreement are due to the lack of knowledge of the boundary conditions at the intake port which are the main input parameters to the theoretical model.
- OSTI ID:
- 5621643
- Journal Information:
- AIAA J.; (United States), Journal Name: AIAA J.; (United States) Vol. 19; ISSN AIAJA
- Country of Publication:
- United States
- Language:
- English
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