Influence of viscosity on aerodynamic sound emission in free space
Influence of viscosity on aerodynamic sound emission in free space
复制标题
粘度对自由空间气动声发射的影响
DOI：
10.1016/0022-460x(84)90674-6
复制
发表时间：
1984
影响因子：
4.7
通讯作者：
T. Kambe
中科院分区：
文献类型：
--
作者：
T. Kambe
考虑到自由空间中声源粘性对声发射的影响，重新建立了气动声理论。这是基于莱特希尔方程的Ffowcs威廉姆斯形式。源流被假定为由一个局部涡量场确定，其特征在于低马赫数和高雷诺数。结果表明，粘性涡运动所产生的声压由一个四极子和两种双极子组成。将源流中的雷诺应力分解为各向同性和非各向同性两部分。非各向同性的部分导致四极波由莫林推导，而各向同性的部分是有关的一个类似的波辐射时，总动能的变化。另一个行波与动能的粘性耗散产生的熵有关。所有这三种成分都受到粘度的影响。
The theory of aerodynamic sound is reformulated with account taken of the influence of viscosity in the source flow on the sound emission in free space. This is based on the Ffowcs Williams form of the Lighthill equation. The source flow is assumed to be determined by a localized vorticity field and characterized by low Mach numbers and high Reynolds numbers. It is found that the acoustic pressure emitted by the viscous vortex motion is composed of a quadrupole and two kinds of monopole. The Reynolds stress in the source flow is decomposed into isotropic and non-isotropic parts. The non-isotropic part leads to the quadrupole wave derived by Möhring, while the isotropic part is related to one of the monopole-like waves radiated when the total kinetic energy changes. The other monopole wave is associated with entropy production by viscous dissipation of the kinetic energy. All three components are influenced by viscosity.