Measurements with Wire Mesh Stacks in Thermoacoustic Prime Movers

摘要

This thesis documents the first measurements of a thermoacoustic prime moverusing wire mesh screens as the stack material. A thermoacoustic prime mover is a heat engine which converts thermal energy to sound. The stack material is sandwiched between the hot and cold heat exchanger and exchanges heat with the cycling gas elements flowing in the stack. The experimental stacks were constructed by inserting disks cut from wire mesh in a tube. In addition to simplicity, these stacks have two significant advantages. First, the wire is relatively impervious to moderately high temperatures and second, the effective thermal conductance of the structure is one to two orders of magnitude lower than a comparable metal 'parallel plate' structure. Since no linear theoretical thermoacoustic model exist for these wire mesh stacks, the approach taken was simply to measure the performance of several different mesh stacks. Results gathered from two different prime movers indicate acoustic onset temperatures and amplitude performance comparable to the best data for parallel plate stacks. Moreover, measured efficiencies for mesh stacks appear to be substantially higher than for parallel plates.