通过内燃机进气道流体的时间分辨实验测量和数值模拟研究
Modern spark-ignited internal combustion engines have intake ports designed to introducehigh levels of so-called “tumble” charge motion. Correspondingly high shear rates can lead to highfluctuations and turbulence within the combustion chamber. A suitable test case to characterize theintake flow is a steady-state flow bench. Although routinely used in the engine development processto determine the global discharge coefficients, only a few detailed numerical and experimentalstudies use this test case to analyze the flow in the vicinity of the valve with high spatial andtemporal resolution. In this paper, we combined highly resolved two-dimensional, two-componentParticle Image Velocimetry (PIV) measurements and numerical simulations using a Detached-EddySimulation (DES) model to characterize engine-relevant flow features on a flow bench. The spatialresolution of numerical simulations on two different grids is assessed and compared to that of thePIV measurement. The results of simulations and experiment are then compared in terms of theirmean and fluctuation velocity fields and the jet orientation. A detailed study of the area around thevalve seats investigates the validity of wall functions in this region. Finally, we examine structuresinduced by vortex-shedding at the valve stem and if they are transported into the combustion chamber.