numerical study of the effect of surface roughness and bubble injection on skin friction in taylor-couette flow

in this research, the effect of surface roughness and bubble injection on skin friction and hydrodynamic drag force has been numerically considered. this research is based on taylor-couette flow. considered flow includes two concentric cylinders which internal cylinder is movable and external is immovable. the effective equations on the flow includes: equations of momentum, continuous, turbulent and bubble distribution. these equations are based on finite volume numerical method and have been solved by second order upwind discrete method. for modeling of two-phase flow used euler-lagrange method. in all of observed views, turbulent flow and taylor vortex has been revealed between spaces of two cylinders. air flow has been injected into the flow as the second phase. selected reynolds range is 104 to 2 × 105 . for validation of the results an experimental study has been used. results showed that friction coefficient will be decreased by reynolds increasing and also, drag force will be decreased by roughness decreasing.