CFD simulation of core annular flow through sudden contraction and expansion

In the present work, a computational fluid dynamic simulation has been performed to investigate core annular flow through sudden contraction and expansion. Core annular flow of lubricating oil and water has been simulated using VOF technique and a satisfactory match between simulated data and experimental results has been obtained. A detailed study has been performed to generate the profiles of velocity, pressure and volume fraction over a wide range of oil and water velocities for an abrupt expansion and contraction. Asymmetric nature of velocity across the radial plane is observed for both the cases. The fouling characteristic of lubricating oil at sudden expansion is also analyzed. The model predicts that fouling can be minimized by increasing the water intake or the pipe diameter.