Subjective loudness of "minimized" sonic boom waveforms.
Subjective loudness of "minimized" sonic boom waveforms.
复制标题
“最小化”音爆波形的主观响度。
DOI：
10.1121/1.382127
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发表时间：
1978
期刊：
影响因子：
--
通讯作者：
H. Ribner
中科院分区：
文献类型：
--
作者：
A. Niedźwiecki;H. Ribner
对于超长超音速飞机来说，“中场”音爆特征在地面上可能还没有完全演变成N波。因此，在当前的最小化弹臂技术中，飞机的形状可以被定制以优化这种中场波形，以降低主观响度。本研究测试了Darden引用的一系列“平顶”波形：除了一个波形外，其他波形的前激波高度（deltapSH）都小于峰值振幅（deltapMAX）。对于相同主观响度，“平顶”与N波（峰值超压δ N），“平顶”特征的峰值幅度明显高于N波；因此，对于相等的峰值振幅，“平顶”信号更安静。deltapSH + 0.11deltapMAX = deltapN；等效性显示了前激波振幅（deltapSH）如何支配响度。所有这些都与约翰逊和罗宾逊的预测方法相一致。
For very long supersonic aircraft the "midfield" sonic boom signature may not have evolved fully into an N wave at ground level. Thus in current boom minimization techniques the shape of the aircraft may be tailored to optimize this midfield wave form for reduced subjective loudness. The present investigation tests a family of "flat-top" waveforms cited by Darden: all but one have a front shock height (deltapSH) less than the peak amplitude (deltapMAX). For equal subjective loudness, "flat top" vs N wave (peak overpressure deltapN), the peak amplitude of the "flat top" signature was found to be substantially higher than that of the N wave; thus for equal peak amplitude the "flat-top" signature was quieter. The results for equal loudness were well fitted by an emperical law deltapSH + 0.11deltapMAX = deltapN; the equivalence shows how the front shock amplitude (deltapSH) dominates the loudness. All this was found compatible with predictions by the method of Johnson and Robinson.