The most recent approach to the ICEs industrial design is increasingly adopting the combined use of numerical and experimental techniques. In particular the 1D design of intake and exhaust systems requires a strong interaction between models and experiments, specifically as far as the poppet valves discharge coefficients are concerned. Usually, discharge coefficients values obtained at a single, constant test pressure level are used. In this paper an experimental and numerical analysis is presented, to perform a first evaluation of the influence of the dependence of high performance engine modeling on discharge coefficient test pressure. To this aim, experimental flow bench tests were performed on a Ducati Corse 4 valves racing engine, at different test pressure levels. A research 1D unsteady code, is used in order to verify the sensibility of the predicted engine performance on the discharge coefficient test pressure: simulations on a simplified engine geometry are performed by supplying to the code discharge coefficient values as function either of the valve lift only, or of both lift and pressure.
Dependence of High Performance Engine Modeling on Discharge Coefficient
GRIMALDI, Carlo Nazareno;POSTRIOTI, Lucio;
2001
Abstract
The most recent approach to the ICEs industrial design is increasingly adopting the combined use of numerical and experimental techniques. In particular the 1D design of intake and exhaust systems requires a strong interaction between models and experiments, specifically as far as the poppet valves discharge coefficients are concerned. Usually, discharge coefficients values obtained at a single, constant test pressure level are used. In this paper an experimental and numerical analysis is presented, to perform a first evaluation of the influence of the dependence of high performance engine modeling on discharge coefficient test pressure. To this aim, experimental flow bench tests were performed on a Ducati Corse 4 valves racing engine, at different test pressure levels. A research 1D unsteady code, is used in order to verify the sensibility of the predicted engine performance on the discharge coefficient test pressure: simulations on a simplified engine geometry are performed by supplying to the code discharge coefficient values as function either of the valve lift only, or of both lift and pressure.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
