Flux enhancement at oscillatory membrane equipped with transverse turbulence promoters has been investigated and an analytical model for predicting the time average quasi steady state flux is developed. The model is based on solving the equation of motion using time-invariant eddy viscosity. It was found that the combined effect of oscillatory motion and turbulence promoters can result in substantial flux augmentation due to the efficient removal of the deposited cake by the mixing and scouring effect of the surface between the promoters. Such effect increased with increasing the oscillations frequency, but decreased with its amplitude. The model predictions agreed satisfactorily with the experimental measurements. (C) 2012 Elsevier B.V. All rights reserved.