一种亚音螺旋桨声场中间面快速算法

 发展了一种改进的亚音螺旋桨声场中间面快速算法。通过引入薄翼假设,在时域里求解ＦｆｏｗｃｓＷｉｌｌｉａｍｓ＆Ｈａｗｋｉｎｇｓ（ＦＷ－Ｈ）方程,对处于自由空间中的亚音螺旋桨声场进行预测。数值计算结果表明,与目前广泛运用的全表面公式（ＳＦＳＭ）、旧中间面公式（ＯＭＳＭ））相比,新发展的快速近似算法（ＮＭＳＭ）所需计算时间和计算机内存约为ＳＦＳＭ方法的５０％,ＯＭＳＭ方法的５０～６０％。若与跨音消失球法（ＴＣＳＭ）相比,所需ＣＰＵ时间只有ＴＣＳＭ法的１０～１３％；而且计算结果也在工程精度允许范围内。在螺旋桨工程设计初期以及所需精度不太高的场合,该法不失为一种可靠的快速算法。

A NEW IMPROVED MEAN SURFACE METHOD FOR SUBSONIC PROPWLLER NOISE PREDICTION

A new improved mean surface method(NMSM)for propeller noise prediction is presented,based on solving the Ffowcs Williams &; Hawking(FW-H)equation in time domain. Numerical calculations show that the NMSM needs only 50% of CPU time and memo-ry of subsonic full surface method(SFSM),50～60% of CPU time and memory of old mean sur-face method(OMSM)and 10～13% of CPU time of transonic collapse sphere method(TCSM),while the calculation accuracy can be assured.Thus,the NMSM could be a good alternative method for subsonic propeller noise prediction,especially in preliminary aeroacoustics design of a new propeller.