The present study attempts to capture flow instability, and possibly turbulence, induced by a typical piston bowl geometry by simulating the flow dynamics using the KIVA-3 code. Both two- and three-dimensional simulations were performed using relatively fine grid resolution in a piston-bowl assembly with various wedge angles in the circumferential direction. These simulations were performed using a maximum time step of 0.15 μs over a compression and expansion stroke repeated twice. The motored engine speed was taken as 600 and 1500 RPM. The differences in solutions using a subgrid scale (SGS) model are elucidated. Simulations with no turbulence model seem to capture a high frequency of the instabilities with significant amplitudes. The r.m.s. values of the fluctuations have been calculated at selected points inside the cylinder. The influence of various numerical parameters on these quantities has been illustrated. The results are encouraging regarding prediction of incylinder turbulence for IC-Engines. Currently, work is under way to validate the computed flow instabilities and understand the underlying physical mechanisms.
|Original language||English (US)|
|Number of pages||6|
|Journal||American Society of Mechanical Engineers, Internal Combustion Engine Division (Publication) ICE|
|State||Published - Dec 1 1998|
ASJC Scopus subject areas