Helmholtz Resonance of Pitot Pressure Measurements in Impulsive Hypersonic Test Facilities
Helmholtz Resonance of Pitot Pressure Measurements in Impulsive Hypersonic Test Facilities
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脉冲高超声速试验设备中皮托压力测量的亥姆霍兹共振
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
C. Jacobs
中科院分区：
文献类型：
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作者：
M. McGilvray;P. Jacobs;R. Morgan;R. Gollan;C. Jacobs
在脉冲装置中的皮托管压力实验测量通常具有与之相关的大尺度谐波波动。一个相结合的实验和数值方法是用来调查，如果亥姆霍兹共振是从保护颗粒的影响，而不是干扰存在于自由流的压力传感器的密封创建。为了通过实验验证这一点，使用液压油来改变腔中的声速。通过对皮托管的数值计算表明，定常和预期瞬态入流均会引起周期相似的亥姆霍兹共振。然而，5%的等温水平的自由流噪声需要匹配的实验波动水平。此外，粘性效应被证明是显着的，在初始瞬态响应的压力测量。一种新的皮托管设计成功地进行了测试，并表明能够减少波动的幅度和周期。
Experimental pitot pressure measurements in impulse facilities have typically had large scale harmonic fluctuations associated with them. A combined experimental and numerical approach is used to investigate if a Helmholtz resonance is created from the shrouding that protects the pressure sensor from particle impact, rather than disturbances being present in the free stream. To verify this experimentally, hydraulic oil was used to change the sound speed in the cavity. Numerical calculations of the pitot probe were used to show that both the steady and the expected transient inflow cause a Helmholtz resonance of similar period. However, a 5% isothermal level of free stream noise was required to match the experimental fluctuation levels. Also, viscous eects were shown to be significant during the initial transient response of the pressure measurement. A new pitot probe design was successfully tested and shown to be able to reduce the magnitude and period of the fluctuations.