A new Low-Reynolds-Number one-equation model of turbulence

In this study, we propose a new Low-Reynolds-Number (LRN) one-equation mode l, which is derived from an LRN two-equation (k-epsilon) model. The derivat ion of the transport equation, in principle, is based on the assumption tha t the turbulent structure parameter remains constant. However, the relation for the turbulent structure parameter a(1) (=\-<(uv)over bar>\/k) is modif ied to account for near-wall turbulence. As a result, the present one-equat ion model contains a term which takes the near-wall limiting behavior expli citly into account. Thus, the present model provides the correct wall-limit ing behavior of turbulence in the vicinity of the wall and can be applied t o the analysis of heat transfer. The validity of the present model is teste d in channel flows, boundary layer flows with and without pressure gradient , plane wall jet, and flow with separation and reattachment. The calculated results showed good agreement with the direct numerical simulation (DNS) a nd experimental data.