Abstract:
Centrifugal force has been used to create a large variety of pumps with pressure differentials which vary from inches of water (blowers) to more than 10 000 atmospheres (compressors). The centrifugal pumping pressure depends upon centripetal acceleration which is directly proportional to the square of the tangential velocity and inversely proportional to the rotational radius. Since the velocity dependence is quadratic, vibratory excitation will also lead to steady fluid flows. Experimental measurements of a vibrocentrifugal pump which is driven by a ``clamped-free'' bar undergoing resonant flexural vibration will be reported. Fluid flow is restricted to a flexible tube attached or internal to the oscillating bar. This process is extremely attractive for the self-pumping of heat transport liquids through the heat exchangers in a torsionally resonant toroidal thermoacoustic refrigerator. In that application, a single motor can be used to provide both the resonant excitation of the acoustic standing wave within the thermoacoustic refrigerator and eliminate the requirement for two separate motors to pump the hot and cold heat transport fluids. [Work supported by the Office of Naval Research.]