This paper presents numerical and experimental investigation of flux augmentation in hybrid spring-ultrafiltration membrane system. The numerical simulation is based on the Eulerian multiphase model. Momentum exchange coefficient was used to account for interaction between the liquid-solid phases. The helical spring insert was modeled as filaments with defined pitch. The experimental facility consists of a two-pass spring-membrane system subjected to iso-transmembrane pressure and inlet velocity. The wall velocity, shear stress and turbulence kinetic energy (TKE) were greatly enhanced and varied intensely by the spring insert. These fluctuations and resulting scouring forces deterred particle deposition on the membrane surface, while the generation of eddy currents after each filament effectively increased local mixing and suppressed development of concentration polarization layer. The simulation results revealed that the volume fraction (VF) distribution was non-uniform between two filaments. Flux was improved by 25%; and the spring diameter can be up to 30% of membrane internal diameter without incurring penalty in pressure drop. Furthermore, observation from a membrane autopsy revealed non-uniformity in buildup of fouling; the fouling pattern mimicked the helical spring contour. Analysis of the membrane surface showed that approximately 60% of the surface was un-fouled. This experimental evidence is consistent with numerical results. (C) 2011 Elsevier B.V. All rights reserved.