A Comparison Between CFD Predictions and Measurements of Inlet Port Discharge Coefficient and Flow Characteristics

Predictions of the volume flow rate through an inlet port were produced by four different commercially available CFD programs suitable for use in a steady flow simulation. These predictions were compared with experimental measurements of an inlet port's discharge coefficients.

The experiment performed was a typical steady state flow bench test for an inlet port. Volume flow rates were measured at five different valve lifts. The largest valve lift tested (12.24mm) was the maximum value of lift under actual operation. The smallest valve lift was typical of early valve opening. The tests were performed at two different pressure differences across the inlet port and valve at each of the five different valve lifts.

All predictions were made using an RNG k-ε turbulence model. Standard wall functions were used to predict wall friction effects and the energy equation was included to account for compressibility effects. Also, a mesh sensitivity study and a study of the effect of different turbulence models was carried out.

Ultimately, five different users using four different CFD programs produced predictions of the volume flow rates that were within 11% of the experimentally determined values.