Experiments on a General Thermoacoustic Engine. Revision

Abstract : Research on thermoacoustic devices has been carried out during the 36 month period ending 14 July, 1992. In the area of general thermoacoustics: (1) Several different setups were constructed to apply arbitrary sound fields to thermoacoustic structures. (2) Detailed computer modeling of the effect of varying the phase of the acoustic impedance of the sound field has been carried out. (3) A simple equivalent thermodynamic circuit model has been developed and computer tested. (4) These setups were used to measure thermoacoustic properties of various grades of steel wool, filter sand, layered stainless steel, and layered mylar. In the area of acoustic resonators: several rotating wave acoustic resonators were built and tested as means to efficiently apply an arbitrary phased sound field to a thermoacoustic device. Single point excitation of these was achieved. Experiments on an arbitrary phased cryocooler were made