In the present work, we studied the squeeze flow behavior of a model soft-jammed material - an Electrorheological (ER) fluid - when it is squeezed between two parallel plates of same roughness under the variation of electric field strength and plate velocity. More precisely, we investigated the effect of electric field-induced jamming towards the friction coefficient (at the interface of plate-surface and the bulk material) using squeeze flow approach in an Electrorheological (ER) fluid in terms of normal force as a function of gap variation. Firstly, the normal force exerted by the fluid on the top plate under the controlled gap conditions was monitored at constant velocity for various combinations of electric-field strength. During the experiment we observed that when squeezing starts, normal force starts to increase, and the force level becomes higher with increase in electric-field intensity. Then, we predicted the experimentally captured force-gap flow curves using the squeeze flow analysis of Herschel-Bulkley model, which also explained self-similarity in squeeze flow behaviour of ER fluids with respect to electric field variation, demonstrating gap-electric field superposition. Furthermore, the model has also rendered an estimate of friction coefficients at the top and the bottom plates as a function of electric field strength. Squeeze flow experiments have been carried out at three different velocities. We observed that friction coefficient increases with increase in magnitude of electric field strength at a fixed plate velocity and remains unaffected by velocity variation. This observation indicates the crucial role of extent of jamming on friction characteristics at interface in squeeze flow behavior.
