Racing Car Airbox Performance Prediction Using LES Simulation Approach 2008-01-2388
This paper deals with the assessment of the use of LES simulation technique on a real airbox geometry designed for a high-performance engine.
Large Eddy Simulation is a promising technique to yield a CFD tool able to predict flow unsteadiness: in LES modeling only a small part of the energy spectrum is modeled while the large scales of motion (correlated with the energy transport phenomena) are directly resolved. Given this observation, LES model becomes a very attractive tool for the fluid dynamic analysis of components characterized by a strong dynamic flow behavior like an airbox geometry.
The airbox simulations were performed by Fluent v6.3 CFD code and the Wall Adaptive Local Eddy-Viscosity (WALE) sub-grid (sgs) stress model was used. A bounded second order central differencing scheme (BCD) was adopted and a discussion of the kinetic energy conservation attitude of this scheme was performed.
In order to perform a reliable airbox LES simulation, the computational domain was constructed on the basis of a classic experimental test bench flow layout used to test the airbox performance. Results obtained by LES simulations were analyzed in terms of mean evolution and rms fluctuations of both pressure and velocity components.
The numerical results obtained from the LES simulation showed as this simulation approach could be used to clearly understand the dynamic interaction between airbox flow behavior and flow conditions on the inlet trumpet sections and to optimize the airbox layout. It is concluded that, today, LES technique is being a very proficient approach to obtain a high fluid dynamic resolution level on industrial cases.