Lattice Boltzmann Computation of Steady Cross-Flow Across a Rectangular Obstacle with Different Aspect Ratio: Effect of Blockage Ratio

This work presents a two dimensional lattice Boltzmann analysis of steady and cross-flow of New tonian fluid across a built-in rectangular cylinder. In particular, the effects of the blockage ratio and aspect ratio of rectangular cylinder (width/height) on the momentum characteristics have been explored for range of flow governing parameters such as, blockage ratio (β = 1/8, 1/12, 1/16), aspect ratio of rectangular cylinder (1 ≤ a_r ≤ 6) at constant Reynolds number of Re = 40 corresponding to the laminar range. The physical insight of system is gained by evaluation of stream-function, vorticity and pressure coefficient variation, etc. Further, the engineering gross parameter, such as drag coefficient is determined for possible use in engineering design purpose. It is observed that the increase in blockage ratio drag coefficient values decreases and drag values show proportional variation with aspect ratio. Finally, a closure relationship is developed between drag coefficient, blockage ratio and aspect ratio of rectangular cylinder for possible use in engineering/scientific practices