Accuracy of large eddy simulation for turbulent flow by the finite element method
This paper investigates the computational accuracy and CPU (central processing unit) time of large eddy simulation (LES) for turbulent flows performed by the finite element method. The investigations are accomplished by simulating a fully developed turbulent channel flow, which was analysed by Kim et al. using the direct numerical simulation (DNS) technique. When the advection term is discretized in gradient form, the turbulence decays and disappears with the passage of time. In using a multipass algorithm to solve the velocity field, the numerical result obtained by discretizing the advection term in divergent form agrees very well with that of the DNS. The multipass algorithm with the number of iterations k = 2 and 3 predict almost the same results. Thus, the algorithm with k = 2, allowing calculation with less CPU time, is successfully applicable to LES.