An axisymmetric numerical simulation approach to the hole-tone feedback problem is developed. It is based on the discrete vortex method and an 'acoustic analogy' representation of flow noise sources. The shear layer of the jet is represented by 'free' discrete vortex rings, and the jet nozzle and the end plate by bound vortex rings. A vortex ring is released from the nozzle at each time step in the simulation. The newly released vortex rings are disturbed by acoustic feedback. The simulated frequencies f follow the criterion L/u_c+L/c_0 = n/f where L is the gap length, u_c is the shear layer convection velocity, C_0 is the speed of sound, and n is a mode number (n = 1/2, 1, 3/2,...). This is in agreement with experimental observations. The numerical model also display mode shifts (jumps in the chosen value of n), as seen in experiments.
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机译：开发了轴对称数值模拟问题的开发了孔色调反馈问题。它基于离散涡流方法和流量噪声源的“声学类比”表示。射流的剪切层由“自由”离散涡旋环，以及喷射喷嘴和端板通过绑定的涡旋环表示。在模拟中的每次步骤中，从喷嘴释放涡旋环。新发布的涡旋戒指受到声反馈的干扰。模拟频率f遵循标准L / U_C + L / C_0 = N / F其中L是间隙长度，U_C是剪切层对流速度，C_0是声速，n是模式号（n = 1 / 2,1,3 / 2，......）。这与实验观察一致。如实验中所见，数值模型也显示模式偏移（跳转N的所选值）。
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