Yasui Kyuichi, Izu Noriya
National Institute of Advanced Industrial Science and Technology (AIST), 2266-98 Anagahora, Shimoshidami, Moriyama-ku, Nagoya 463-8560, Japan.
J Acoust Soc Am. 2017 Jun;141(6):4398. doi: 10.1121/1.4985385.
Acoustic oscillations of a fluid (a mixture of gas and vapor) parcel in a wet stack of a thermoacoustic engine are numerically simulated with a Lagrangian approach taking into account Rott equations and the effect of non-equilibrium evaporation and condensation of water vapor at the stack surface. In a traveling-wave engine, the volume oscillation amplitude of a fluid parcel always increases by evaporation and condensation. As a result, pV work done by a fluid parcel is enhanced, which means enhancement of acoustic energy in a thermoacoustic engine. On the other hand, in a standing-wave engine, the volume oscillation amplitude sometimes decreases by evaporation and condensation, and pV work is suppressed. Presence of a tiny traveling-wave component, however, results in the enhancement of pV work by evaporation and condensation.
采用拉格朗日方法，考虑罗特方程以及热声发动机湿堆栈中水蒸气非平衡蒸发和冷凝的影响，对热声发动机湿堆栈中流体（气体和蒸汽的混合物）微团的声振荡进行了数值模拟。在行波发动机中，流体微团的体积振荡幅度总是通过蒸发和冷凝而增大。结果，流体微团所做的pV功得到增强，这意味着热声发动机中的声能增强。另一方面，在驻波发动机中，体积振荡幅度有时会因蒸发和冷凝而减小，pV功受到抑制。然而，存在微小的行波分量会导致蒸发和冷凝增强pV功。
