Combustion effects on the preflame flow field in a spark-ignited engine
Measurements of motored and conditionally-sampled fired (preflame) turbulence intensities and mean velocities have been taken in a research engine for two engine configurations. During one set of measurements, a grid was installed in the combustion chamber to attempt to control the fluid motion at the time of ignition. The engine speed for this set of experiments was 300 RPM. The other set of data were taken at the more typical engine speed of 1200 RPM with identical valve and cylinder geometry and without the grid. From motoring studies with different grid geometries, it was shown that the resulting flow was not a strong function of grid configuration. For the grid used in the firing studies, the motion was characterized by zero mean motion and homogeneous turbulence at the time of ignition. Fired pressure tests revealed that the grids had a significant effect on the combustion cyclic variation. Without a grid the COV (standard deviation in peak pressure divided by the mean peak pressure) measured 0.022, while with a grid was as low as 0.0075. The conditionally-sampled fired measurements demonstrated the effects of combustion on the preflame flow field.
- Research Organization:
- Michigan Univ., Ann Arbor (USA)
- OSTI ID:
- 5429693
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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