Experimental study of a radial mode thermoacoustic prime mover

The purpose of this research is to branch out from thermoacoustics in the p lane wave geometry to study radial wave thermoacoustic engines. The radial wave prime mover is described. Experimental results for the temperature dif ference at which oscillations begin are compared with theoretical predictio ns. Predictive models often assume a uniform pore size and temperature cont inuity between the stack and heat exchangers; however, stacks of nonuniform pore size and temperature discontinuities between the stack and heat excha ngers are common imperfections in experimental devices. The radial engine r esults are explained using a theoretical model which takes into account the se prevalent construction flaws. Theory and experiment are shown to be in a greement after the complications are included. Spectral measurements show t hat an additional feature of the radial geometry is the anharmonicity of th e resonant modes which significantly reduces nonlinear harmonic generation. (C) 1999 Acoustical Society of America. [S0001-4966(99)05603-9].