Effect of Counter-Rotating Cylinder with Surface Roughness on Stagnation and Separation Point – A Computational Approach

This paper is devoted to a two-dimensional numerical study of the influence of surface roughness on the cross-flow around a Counter-Rotating Cylinder. The surface roughness consists of irregular notches periodically distributed on the cylinder surface. The roughness was varied using different notch patterns and heights. The roughness patterns were tested on the cylinder. It was investigated approximately using two-dimensional block with average height and different shapes periodically distributed on a smooth cylinder. The influence of the roughness on the drag coefficient, stagnation point pattern and location of separation point was studied numerically over the range of Reynolds numbers 2.0 x 103 < Re < 4.2 x 104 at rotating speed 400 rpm. In the Counter-Rotating Cylinder with roughness, no as well as different observed on drag coefficient prediction compared with previously published. However, the stagnation point and separation point on roughness cylinder is quite difference between a smooth cylinder.