Improvement of an LRN two-equation turbulence model reflecting multi-time scales

•We study the improvement of linear two-equation turbulence model.•The proposed two-equation turbulence model includes new time-scales.•The predictions of proposed model are evaluated in various complex turbulence fields.•The proposed model predicts good agreement with experimental data.

It is well known that turbulence energy is overpredicted by the linear k  –εε model at the stagnation point. This problem causes inadequate predictions of the flow field. In this paper, to evaluate the performance of a low-Reynolds-number (LRN) type turbulence model for flows on a complex wall shape, we carried out simulations of flows around various wall shapes. Based on this evaluation, we improved the model by introducing a time scale based on the velocity gradient parameter. The proposed model is evaluated in four complex turbulent flows, i.e., forward-facing step, two-dimensional block, two-dimensional hill and three-dimensional block flows. The results, together with the proposed model, are in good agreement with the experimental data.