Flow structures and losses in the exhaust port of an internal combustion engine
2014 (English)In: ASME 2013 International Mechanical Engineering Congress & Exposition: Fluids Engineering Systems and Technologies, ASME Press, 2014Conference paper (Refereed)
A numerical study of the flow in the exhaust port geometry of a Scania heavy-duty Diesel engine is carried out mainly by using the Large Eddy Simulation (LES) approach. Unsteady Reynolds Averaged Navier-Stokes (URANS) simulation results are included for comparison purposes. The calculations are performed with fixed valve and stationary boundary conditions for which experimental data are available. The simulations include a verification study of the solver using different grid resolutions and different valve lift states. The calculated numerical data are compared to existent measured pressure loss data. The results show that even global parameters like total pressure losses are predicted better by LES than by URANS. The complex three-dimensional flow structures generated in the flow field are qualitatively assessed through visualization and analyzed by statistical means. The near valve region is a major source of losses. Due to the presence of the valve, an annular, jet-like flow structure is formed where the high-velocity flow follows the valve stem into the port. Flow separation occurs immediately downstream of the valve seat on the walls of the port and also on the surface of the valve body. Strong longitudinal, non-stationary secondary flow structures (i.e. in the plane normal to the main flow direction) are observed in the exhaust manifold. Such structures can degrade the efficiency of a possible turbine of a turbocharger located downstream on the exhaust manifold.
Place, publisher, year, edition, pages
ASME Press, 2014.
Exhaust port manifold, exit valve port, loses, flow structures, LES, ICE
Research subject SRA - Energy
IdentifiersURN: urn:nbn:se:kth:diva-124135DOI: 10.1115/IMECE2013-64610ISI: 000359959700045ScopusID: 2-s2.0-84903486900ISBN: 978-079185631-4OAI: oai:DiVA.org:kth-124135DiVA: diva2:633191
ASME 2013 International Mechanical Engineering Congress and Exposition, IMECE 2013; San Diego, CA; United States; 15 November 2013 through 21 November 2013
QC 201307192013-06-262013-06-262015-09-18Bibliographically approved