Anisotropic turbulent model based on V2f model for natural and mixed convection in enclosed spaces

Abstract

In previous work (Zhang et al. 2007) several Reynolds-averaged Navier–Stokes turbulent models were evaluated by the classic natural convection experiment. It was demonstrated that the V2f turbulent model shows the best overall performance compared to other models in terms of accuracy of temperature, velocity, and turbulent kinetic energy. However, all compared turbulent models cannot simulate the pseudo-laminar phenomenon in the center zone of the classic natural convection experiment. Moreover, the V2f model needs to solve four equations, and the transport equation for the wall normal stress () and the elliptic equation for the relaxation function (f) make the model numerically unstable. Based on the idea of the V2f model, an anisotropic model (BV2fAM) was developed. In the BV2fAM model, as the turbulent kinetic intensity normal to streamlines was adopted and computed by local turbulent kinetic energy and local flow characteristic variable instead of the transport equation. The validity of the developed BV2fAM model was confirmed by two benchmark cases (classic natural convection in a tall cavity and mixed convection in a square cavity). It can be seen that the developed BV2fAM model can yield better simulated results of temperature, velocity, and turbulent kinetic energy than other compared models. Moreover, it can simulate the pseudo-laminar phenomenon in the center zone of the classic natural convection experiment.