Experimental investigation of interactions between turbulent cylinder wake and spherical shock wave
Experimental investigation of interactions between turbulent cylinder wake and spherical shock wave
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DOI：
10.1063/1.5128267
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发表时间：
2020-01
影响因子：
4.6
通讯作者：
Kentaka Aruga;K. Inokuma;Tomoaki Watanabe;K. Nagata;Y. Sakai
中科院分区：
文献类型：
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作者：
Kentaka Aruga;K. Inokuma;Tomoaki Watanabe;K. Nagata;Y. Sakai
通过风洞实验研究了球形冲击波和湍流圆柱尾流之间的相互作用。冲击波在尾流外部产生并在湍流尾流中传播。瞬时流向速度是在尾流中心线上测量的，而冲击波的峰值超压是在冲击波穿过尾流后在尾流外部测量的。针对圆柱尾流的各种条件进行了实验，以研究均方根（rms）速度波动和冲击波传播的湍流区域长度的影响。与激波传播方向相反的速度脉动与峰值超压脉动正相关。冲击波在尾流中传播后，平均峰值超压下降。速度和峰值超压之间的这些关系可以通过冲击表面变形来解释，其中对于相对于冲击传播方向具有凹形和凸形形状的冲击表面，峰值超压分别增大和减小。速度与峰值超压波动和均方根峰值超压波动之间的相关系数随着均方根速度波动而增大。一旦冲击波传播通过足够长的湍流区域，均方根峰值超压波动就与冲击射线上的湍流长度无关。尽管尾流中速度波动的概率密度函数 (PDF) 呈负偏斜，但峰值超压脉动的概率密度函数 (PDF) 接近高斯形状。通过风洞实验研究了球形冲击波与湍流圆柱尾流之间的相互作用。冲击波在尾流外部产生并在湍流尾流中传播。瞬时流向速度是在尾流中心线上测量的，而冲击波的峰值超压是在冲击波穿过尾流后在尾流外部测量的。针对圆柱尾流的各种条件进行了实验，以研究均方根（rms）速度波动和冲击波传播的湍流区域长度的影响。与激波传播方向相反的速度脉动与峰值超压脉动正相关。冲击波在尾流中传播后，平均峰值超压下降。速度和峰值超压之间的这些关系可以通过冲击表面变形来解释，其中峰值超压分别增加和减少......
Interactions between a spherical shock wave and a turbulent cylinder wake are studied with wind tunnel experiments. The shock wave is generated outside the wake and propagates across the turbulent wake. Instantaneous streamwise velocity is measured on the wake centerline while peak overpressure of the shock wave is measured outside the wake after the shock wave has passed across the wake. The experiments are performed for various conditions of the cylinder wake to investigate the influences of the root-mean-squared (rms) velocity fluctuation and of the length of the turbulent region through which the shock wave propagates. The velocity fluctuation opposite to the shock propagation direction is positively correlated with the peak-overpressure fluctuation. The mean peak overpressure decreases after the shock wave propagates in the wake. These relations between velocity and peak overpressure are explained by the shock-surface deformation, where the peak overpressure is increased and decreased, respectively, for the shock surfaces with concave and convex shapes in relation to the shock propagation direction. The correlation coefficients between the velocity and peak-overpressure fluctuations and the rms peak-overpressure fluctuation increase with the rms velocity fluctuation. The rms peak-overpressure fluctuation becomes independent of the turbulent length on the shock ray once the shock wave has propagated through a sufficiently long turbulent region. The peak-overpressure fluctuation has a probability density function (PDF) close to a Gaussian shape even though the PDF of velocity fluctuations in the wake is negatively skewed.Interactions between a spherical shock wave and a turbulent cylinder wake are studied with wind tunnel experiments. The shock wave is generated outside the wake and propagates across the turbulent wake. Instantaneous streamwise velocity is measured on the wake centerline while peak overpressure of the shock wave is measured outside the wake after the shock wave has passed across the wake. The experiments are performed for various conditions of the cylinder wake to investigate the influences of the root-mean-squared (rms) velocity fluctuation and of the length of the turbulent region through which the shock wave propagates. The velocity fluctuation opposite to the shock propagation direction is positively correlated with the peak-overpressure fluctuation. The mean peak overpressure decreases after the shock wave propagates in the wake. These relations between velocity and peak overpressure are explained by the shock-surface deformation, where the peak overpressure is increased and decreased, respectively, ...