APPLICATION OF TWO VERSIONS OF A RNG BASED k-ε MODEL TO NUMERICAL SIMULATIONS OF TURBULENT IMPINGING JET FLOW

摘要

Two independent versions of the RNG based k-ε turbulence model in conjunction with the law of the wall have been applied to the numerical simulation of an axisym-metric turbulent impinging jet flow field. The two model predictions are compared with those of the standard k-ε model and with the experimental data measured by LDV (Laser Doppler Velocimetry). It shows that the original version of the RNG k-ε model with the choice of C_(ε1) = 1. 063 can not yield good results, among them the predicted turbulent kinetic energy profiles in the vicinity of the stagnation region are even worse than those predicted by the standard k-ε. model. However, the new version of RNG k-ε model behaves well. This is mainly due to the corrections to the constants C_(ε1) and C_(ε2) along with a modification of the production term to account for non-equilibrium strain rates in the flow.