In the present investigation, the effect of piston and valve motion on the flow field and the discharge coefficient predictions is analyzed numerically for hot engine-like conditions. Therefore, three simulation strategies are compared, i.e. fixed valve and fixed piston, fixed valve and moving piston, and moving valve and moving piston. The flow field resulting for each of the different approaches is briefly described and analyzed. The flow variables governing the performance of the exhaust port design are sampled over the exhaust cycle and compared. Thereby, the investigation elucidates the consequences of applying a fixed valve lift, ‘‘cold’’ laboratory conditions, and a constant inflow boundary condition
for evaluating the discharge coefficient as compared to a real engine case scenario. One has to note that fixed valve lifts and cold flow conditions are characteristic to the flow bench experiments typically carried out in industry.