Department of Mechanical Engineering, Brigham Young University, Provo, Utah 84602, USA.
Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602, USA.
JASA Express Lett. 2023 Jul 1;3(7). doi: 10.1121/10.0019866.
Classical jet noise theory indicates that radiated sound power is proportional to the jet velocity raised to the eighth and third powers for subsonic and supersonic jets, respectively. To connect full-scale measurements with classical jet noise theory, this letter presents sound power and acoustic efficiency values for an installed GE-F404 engine. When subsonic, the change in sound power follows the eighth-power law, and the sound power change approximately follows the third-power law at supersonic conditions, with an acoustic efficiency of ∼0.5-0.6%. However, the OAPWL increase from subsonic to supersonic jet velocities is greater than would be predicted.
经典喷流噪声理论表明，辐射声功率与亚声速和超声速射流的喷流速度的 8 次方和 3 次方成正比。为了将全尺寸测量与经典喷流噪声理论联系起来，本函件给出了安装的 GE-F404 发动机的声功率和声学效率值。在亚声速时，声功率的变化遵循 8 次幂定律，而在超声速条件下，声功率的变化大致遵循 3 次幂定律，声学效率约为 0.5-0.6%。然而，从亚声速到超声速射流速度的 OAPWL 增加量大于预测值。
