可压缩与不可压缩流体中Rayleigh-Taylor不稳定性的比较

对比研究了可压缩与不可压缩流体的Rayleigh-Taylor不稳定性小扰动阶段的增长速率,其中可压缩流体的状态方程为压力是密度的任意单值函数。研究表明:在相同密度分布条件下,可压缩流体的界面扰动增长速率总是比相应的不可压缩流体的界面增长率大,其相对增长率D随扰动波长的增加而增大,也随两种介质的声速减少而增大,在长波和易压缩流体中,D值可达0.8以上。因此,在某些条件下,流体可压缩性对R-T不稳定性的影响是不能忽略的。

Comparison between Rayleigh-Taylor Instabilities of Compressible and Incompressible Fluid(In Chinese)

Comparison between Rayleigh-Taylor instability growth rates of compressible and incompressible fluid is made, with the state equation of compressible fluid in an arbitrary function form of density and pressure. It is shown that with the same density distribution, interface perturbation growth rate of compressible fluid is always greater than the counter one. The relative growth rate D increases with perturbation wavelength, and decreases with velocity of sound of upper and lower fluid. The value of D can exceed 0. 8 at long wave and more compressible fluid, so compressibility of fluid shouldn't be neglected at some conditions.