Turbulent flow simulation in a square duct using generalized lattice Boltzmann equation

Turbulent flow simulation in a square duct using generalized lattice Boltzmann equation

In the present work we exhibit flow structure of Turbulent flow in a straight square duct driven by a pressure gradient. We implement generalized lattice Boltzmann equation (GLBE) using multiple relaxation times with forcing term in this case. The implementation of LBM is on a GPU (Graphic Processing Unit) platform using CUDA (Compute Unified Device Architecture). In this work we accurately using a CUDA code of a lattice Boltzmann solver for simulating turbulent duct flow. We present the combination of LBM and CUDA for computation of turbulent duct flow for which large eddy simulation (LES) was employed as a turbulence model and compare our results with the results of direct numerical simulation (DNS). The sub grid scale (SGS) turbulence effects were simulated through a shear-improved Smagorinsky model (SISM), which is capable of predicting turbulent near wall region accurately without any wall function. Computations were done for fully developed turbulent duct flow at Re 300   , based on duct width and average friction velocity. It was concluded that using GPUs decrease the cost and the time of computation which help us to solve many practical problems. The defect of nowadays GPUs is that they are single precision.