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Considering from the second law of thermodynamics, the equation for entropy generation rate near a single-plate, representative of the stack inside thermoacoustic refrigerators was derived in this paper. It indicates that entropy generation is produced due to heat transfer in the x-y direction of finite temperature gradients and fluid friction irreversibility. Analysis of global entropy generation rate versus the position of the stack, 2x/λ and the volume porosity, ϕ were carried out. The results demonstrated that the optimal position of the stack was within 0.8 <2x/λ <0.83, and the optimal volume porosity was 0.7. [ABSTRACT FROM AUTHOR]

Based on linear thermoacoustic theory, an open-air traveling-wave thermoacoustic generator with 1 bar air has been designed and built up. The dimensions of regenerator and resonator influence on the resonant frequency, driver ratio, acoustic power and temperature difference are simulated and optimized to acquire the perfect performance, respectively. According to above simulated results, the acoustic pressures at the open end and 0.5 m far away from the open end of the resonator versus the heating power are investigated experimentally. The improved maximum acoustic pressures are up to 133 dB and 101 dB ref 20 μPa, respectively. [ABSTRACT FROM AUTHOR]

To research the influence of ground parameters on the dynamic responses of anchored bedding rock slope, a dynamic numerical simulation model of bedding rock slope with bolts was established using FLAC3D. The alteration of dynamic response with displacements and accelerations at monitoring points along the slope surface was set as analysis basis. The effects on dynamic responses of slope with different ground parameters, such as waves, frequencies and amplitudes were analyzed. It demonstrated great help for the dynamic stability analysis and slope design when it is supported with anchor under earthquake. [ABSTRACT FROM AUTHOR]