论文标题
从不均匀流动的转子发出的声音
Sound from rotors in non-uniform flow
论文作者
论文摘要
进行了分析，以评估在不均匀电位流中旋转源的声场。除了限制低流量马赫数外，该方法是精确且一般的。具有源位置的辐射特性的变化通过表示为傅立叶级数，以源角度为单位，从而导致通过该系列的求和评估的不对称变化的声场。该方法用于开发一个精确的解决方案，用于在横流中在气缸附近运行的转子的模型问题，样品计算证明了与完整数值评估相比，该技术的准确性。计算显示，由于流量不均匀为0.15，声场中大于一个分贝的变化，这是螺旋桨飞机起飞时的典型速度。
An analysis is presented for the evaluation of the acoustic field of a rotating source in a non-uniform potential flow. Other than the restriction to low flow Mach numbers, the method is exact and general. The variation in radiation properties with source position is handled by representation as a Fourier series in source angle, giving rise to an asymmetrically varying acoustic field evaluated by summation of the series. The method is used to develop an exact solution for the model problem of a rotor operating near a cylinder in cross-flow and sample calculations demonstrate the accuracy of the technique when compared to full numerical evaluation. The calculations show changes of greater than one decibel in the acoustic field due to flow non-uniformity at a flow Mach number of 0.15, a typical speed for propeller aircraft at take-off.
