Effect of Air Bubbles Injection on Drag Reduction in Taylor-Couette Flows

The phenomenon of skin friction drag reduction were investigated numerically in this work. In this case, Taylor-Couette flow between two concentric cylinders is considered where the inner cylinder rotates and the outer one is fixed. The effect of microbubbles injection compared to no air injection in the flow. Eulerian- Lagrangian for two phase flow approach was employed. Finite volume method was used to discrete the governing equations. For the discretization of momentum and turbulence equations, second order upwind scheme was used. The effect of Reynolds number and bubbles injection have been investigated on the skin friction coefficient reduction. The variation of Taylor vortices wavelength with Reynolds number has been studied. The results have been shown that when the Reynolds number increase up to 10000, skin friction coefficient decrease in both with and without air injection. On the other hand, when the bubbles injected into the flow, skin friction coefficient decreases when Reynolds numbers increase. When Reynolds number increase and bubbles injected, the Taylor vortices wavelength increase. Moreover, this numerical method validates with available experimental data and results show good accordance with them.

کلیدواژه ها:

Skin friction reduction ، Taylor-Couette flow ، Eulerian-Lagrangian ، Tayor vortices