Compliant Surfaces under Shear: Elastohydrodynamic Lift Force

Lift force in bubbly suspensions

Closure relations are presented for the lift coe.cient for ordered arrays of 2-D and 3-D bubbles at various bubble volume fractions. These were determined via lattice Boltzmann simulations of bubble rise in periodic boxes, where the bubbles were also subjected to shear. The single-bubble lift coe.cient, determined by low-shear computational experiments, varies in a systematic manner with the as...

A surface force apparatus for nanorheology under large shear strain

A surface force apparatus for nanorheology under large shear strain

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Surface force apparatus for nanorheology under large shear strain.

We describe a surface force apparatus designed to probe the rheology of a nanoconfined medium under large shear amplitudes (up to 500 microm). The instrument can be operated in closed loop, controlling either the applied normal load or the thickness of the medium during shear experiments. Feedback control allows us to greatly extend the range of confinement/shear strain attainable with the surf...

Dynamic Measurement of Valve Lift Force

The paper describes tests carried out on disc valves in which the valve seat was withdrawn from the valve wh).le a pressure difference existed across the valve. Simultaneous measurements were made of the force on the valve, the pressure in the plenum chamber and the displacement of the seat from the valve. Force measurements are compared with values of force measured during continuous flow cond...