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

Keywords:

Turbulent flow , duct flow , Generalized lattice Boltzmann equation , Large eddy simulation , Shear improved smagorinsky model , CUDA