A CASE STUDY REGARDING THE IN-CYLINDER AIR MOTION CHARACTERISTICS IN A MOTORED GASOLINE ENGINE: CFD VS. PIV

Autor/autori: George Trică, Iorga-Simăn Victor, Adrian Clencia, Stéphane Guilainc Amélie Danlos, Rodica Niculescu


Abstract: Fuel economy is a prime objective in order to meet regulatory and customer demands. Given this context, engine manufacturers are forced to introduce complex systems such as variable valve actuation (VVA). One of the simplest form of a VVA system is what is usually called as variable valve timing (VVT). What’s important in these particular cases is in what way the internal aerodynamics and gas exchange phenomena interacts. To study internal aerodynamics, 2 methods are used: an experimental one, employing PIV (particle image velocimetry) technique (for instance) and a numerical one, employing 3D CFD simulation. In the present study, the internal aerodynamics of a motored VVT gasoline engine is examined by using the 2 methods presented above. The purpose is to see the correlation degree between the experimental results obtained on a transparent single cylinder engine through PIV technique and the ones obtained from a three dimensional CFD (computational fluid dynamics) simulation through RANS (Reynolds-Averaged Navier Stokes) approach. The paper describes the methodology used to perform the CFD simulation, the experimentation and the PIV - CFD comparison; it also discusses about the limitation of the CFD simulation and about the difficulties of such a study.

Keywords: internal aerodynamics, tumble, CFD, PIV.

 

DOWNLOAD PDF