Performance of solar powered thermoacoustic engine at different tilted angles

In this study, the thermodynamic performance of a thermoacoustic engine charged with different working fluids were examined at different tilted angles ranging from -90 degrees to 900 with 450 angular interval. The results suggest that the influence of the tilted angle on the onset temperature of the engine depends on the viscidity of the working gas. The lower the viscidity is, the more obvious the influence is. The difference between the maximum and the minimum onset temperature of the engine charged with nitrogen could be as high as 52 degrees C, but the difference for system charged with helium is only about 1.5 degrees C. The tilted angle has little or no effect on the pressure oscillation amplitude, pressure ratio, resonance frequency and the relation of the temperature versus heat power. They are mainly affected by the properties of the working gas. Furthermore, the interactions of the oscillatory motion and the natural convection of the working gas within the thermoacoustic core were also examined. The properties are of importance for the thermoacoustic engine driven by two-axis solar collector, for the tilted angle of the engine varies with the sun position. (c) 2009 Published by Elsevier Ltd.