RESUMO
The best working gases for thermoacoustic refrigeration have high ratios of specific heats and low Prandtl numbers. These properties can be optimized by the use of a mixture of light and heavy noble gases. In this paper it is shown that light noble gas-heavy polyatomic gas mixtures can result in useful working gases. In addition, it is demonstrated that the onset temperature of a heat driven prime mover can be minimized with a gas with large Prandtl number and small ratio of specific heats. The gas properties must be optimized for the particular application of thermoacoustics; it cannot be assumed that high specific heat ratio and low Prandtl number are always desirable.
Assuntos
Acústica , Gases , Condutividade Térmica , Engenharia , Modelos TeóricosRESUMO
A kinetic model is proposed to account for the translational heating of the atmosphere in the vicinity of an ir laser beam. The theory required to link the kinetic model to the temperature rise is developed assuming a still atmosphere. The kinetic model and theoretical method are applied to 10-6-micro CO(2) laser radiation propagation.