Flow induced Energy Losses in the Exhaust Port of an Internal Combustion Engine

Authors: Wang, Y. W., Semlitsch, B., Mihaescu, M, Fuchs, L.F.
Document Type: Article
Pubstate: Published
Journal: J. Fluids Eng.
Volume: 137(1)   011105-1/9.
Year: 2014


A numerical study of the flow in the exhaust port geometry of a Scania heavy-duty Diesel engine is performed using the Large Eddy Simulation (LES) and the Unsteady Reynolds Averaged Navier-Stokes (URANS) simulation approach. The calculations are performed at fixed valve positions and stationary boundary conditions to be able to compare to experimentally measured pressure loss data. Even global parameters, as e.g. the total pressure losses, are predicted better by LES than with URANS. The complex three-dimensional flow structures generated in the flow field are qualitatively assessed through visualization and analyzed by statistical means. The major source of kinetic energy losses occurs in the proximity of the valve. Flow separation occurs immediately downstream of the valve seat. Strong helical flow structures are observed in the exhaust manifold, which are caused due to the displaced exhaust ports with respect to the exit pipe.