APPLICATION OF A MODIFIED QUICK SCHEME TO DEPTH-AVERAGED k-ε TURBULENCE MODEL BASED ON UNSTRUCTURED GRIDS

【摘要】 The modified QUICK scheme on unstructured grid was used to improve the advection flux approximation, and th depth-averaged k ? ε turbulence model with the scheme based on FVM by SIMPLE series algorithm was established and applied to spur-dike flow computation. In this model, the over-relaxed approach was adopted to estimate the diffusion flux in view of it advantages in reducing errors and sustaining numerical stability usually encountered in non-orthogonal meshes. Two spur-dike case with different defection angles (90oand 135o) were analyzed to validate the model. Computed results show that the predicted velocities and recirculation lengths are in good agreement with the observed data. Moreover, the computations on structured and unstructured grids were compared in terms of the approximately equivalent grid numbers. It can be concluded that the precision with unstructured grids is higher than that with structured grids in spite that the CPU time required is slightly more with unstructured grid Thus, it is significant to apply the method to numerical simulation of practical hydraulic engineering.更多还原

【Abstract】 The modified QUICK scheme on unstructured grid was used to improve the advection flux approximation, and th depth-averaged k ? ε turbulence model with the scheme based on FVM by SIMPLE series algorithm was established and applied to spur-dike flow computation. In this model, the over-relaxed approach was adopted to estimate the diffusion flux in view of it advantages in reducing errors and sustaining numerical stability usually encountered in non-orthogonal meshes. Two spur-dike case with different defection angles (90oand 135o) were analyzed to validate the model. Computed results show that the predicted velocities and recirculation lengths are in good agreement with the observed data. Moreover, the computations on structured and unstructured grids were compared in terms of the approximately equivalent grid numbers. It can be concluded that the precision with unstructured grids is higher than that with structured grids in spite that the CPU time required is slightly more with unstructured grid Thus, it is significant to apply the method to numerical simulation of practical hydraulic engineering.更多还原