In the present study, the effect of expansion corner on suddenly expanded flow process has been studied. Experimental investigations have been carried out on a convergent-divergent (C-D) nozzle and isolator duct, where the expansion of the channel is formed through the presence of a 1, 2 and 3 expansion corners (EC) respectively. Flow from nozzle exit of the nozzle of Mach, M = 2.0 was suddenly expanded into the axi-symmetric duct having a cross sectional area of 4.84 times the nozzle exit area. The wall static pressure along the length of the duct and the Pitot pressure at the exit plane of the duct were measured for all the configurations. Computational fluid dynamics (CFD) technique was employed for visualizing the shock-train in the expanded duct. The isolator with one expansion corner was found to be more efficient in achieving a high static pressure rise. The experimental and numerical wall static pressure distribution values were compared for isolators with EC = 2 and found to be in good agreement with each other with a maximum absolute percentage deviation of 11%.

中文翻译：

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膨胀角对隔振器性能影响的实验和数值研究

在本研究中，已经研究了膨胀角对突然膨胀流动过程的影响。已经对收敛-发散（CD）喷嘴和隔离器导管进行了实验研究，其中通道的膨胀分别通过存在1、2和3个膨胀角（EC）形成。来自Mach喷嘴的喷嘴出口的流量M = 2.0突然膨胀到横截面面积为喷嘴出口面积的4.84倍的轴对称管道中。对于所有配置，都测量了沿导管长度的壁静压力和导管出口平面的皮托管压力。计算流体动力学（CFD）技术用于可视化膨胀管道中的冲击波。发现具有一个膨胀角的隔离器在实现高静压升高方面更为有效。对EC = 2的隔离器的实验和壁静压分布数值进行了比较，发现彼此之间具有很好的一致性，最大绝对百分比偏差为11％。