Influence of Thermal Non-equilibrium on Nozzle Flow Condition of High Enthalpy Shock Tunnel HIEST
Influence of Thermal Non-equilibrium on Nozzle Flow Condition of High Enthalpy Shock Tunnel HIEST
复制标题
热非平衡对高焓激波风洞HIEST喷嘴流动条件的影响
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
H. Tanno
中科院分区：
文献类型：
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作者：
Masahiro Takahashi;M. Kodera;K. Itoh;T. Komuro;Kazuo Sato;H. Tanno
采用热化学非平衡模型对自由活塞驱动激波风洞HIEST喷管流场进行了轴对称RANS数值模拟。将喷管出口静压和皮托管压力分布与实验结果进行了比较，考察了热不平衡对喷管流动的影响，验证了CFD程序的正确性。作为热非平衡模型，Park的两个温度模型和四个温度模型，其中分别考虑了N2，O2和NO的振动电子激发能守恒，被应用到程序中。结果表明，HIEST喷管流场以空气为试验气体时接近热平衡，以氮气为试验气体时接近热不平衡。计算流体动力学与实验结果之间的良好协议，得到的总焓条件为3.81兆焦耳/千克与空气和7.99兆焦耳/千克与氮气。然而，在10.0和19.0 MJ/kg空气条件下，皮托管压力分布出现了一些差异。采用4T模型的计算流体动力学未模拟3.81 MJ/kg条件下的空气喷嘴流。结果表明，4T模型低估了振动弛豫速率。
Axisymmetric RANS simulations using thermal and chemical non-equilibrium models are applied to a nozzle flow of a free-piston driven shock tunnel HIEST. The static pressure and Pitot pressure profiles at the nozzle exit are compared with the experimental results to examine influence of thermal non-equilibrium on the nozzle flow and validate the CFD code. As the thermal non-equilibrium model, the two-temperature model of Park and a fourtemperature model, for which the conservation of the vibrational-electronic excitation energy for N2, O2 and NO is taken into account individually, are applied to the code. The results show that the HIEST nozzle flow is close to thermal equilibrium with air as the test gas and thermal non-equilibrium with nitrogen. Good agreement between the CFD and the experimental results is obtained at the total enthalpy conditions of 3.81 MJ/kg with air and 7.99 MJ/kg with nitrogen. However, some discrepancy in the Pitot pressure profiles appears at the 10.0 and 19.0 MJ/kg conditions with air. The CFD with the 4T model does not simulate the air nozzle flow at the 3.81 MJ/kg condition. The results indicate that the 4T model underestimates the vibrational relaxation rate.