A comparative study of highly underexpanded nitrogen and hydrogenjets using large eddy simulation
Li XP(李晓鹏) ; Wu K(吴坤) ; Yao W(姚卫) ; Fan XJ(范学军)
Source Publication 20th AIAA International Space Planes and Hypersonic Systems and Technologies Conference, 2015
2015
Conference Name 20th AIAA International Space Planes and Hypersonic Systems and Technologies Conference, 2015
Conference Date July 6, 2015 - July 9, 2015
Conference Place Glasgow, United kingdom
Abstract The three-dimensional large eddy simulations of highly underexpanded hydrogen and nitrogen jets at the same NPR of 5.60 at Re~105are performed. The flow characteristic for both jets are discussed and compared in detail based on the high resolution LES data. It is found that the H2jet mixes more rapidly with the ambient air but has a much smaller mixing area on cross-section planes. The classical near-field structures of highly underexpanded jets are well captured by the current LES modeling, and the shape and size of Mach barrel for both jets are very similar and also agree well with the experimental measurement and the previous studies. However, the flow field and the shock structures after the Mach disk differ greatly. The density values in the annular shear layer for H2jet aremuch lower because of its smaller molecular mass. Meanwhile, the H2jet has a much longer jet core and more shock cells. In addition, the dominant instability mode is helical for the N2jet, but is axisymmetric for the H2jet. There are two discrete peaks of fs=37.086 kHz and f2s=45.695 kHz in the spectrum of the N2jet, which are both single helical modes.The spectrum of the H2jet is characterized by a fundamental screech frequency of fs=47.020 kHz and its high order harmonics. © 2015, AIAA American Institute of Aeronautics and Astronautics. All rights reserved.
Keyword Comparative Studies
Flow Charac
Teristics
High Order Harmonics
High Resolution
Instability Modes
Near
Field Structure
Shock Structure
Under
Expanded Jets
Department LHD超声速燃烧
ISBN 9781624103209
URL 查看原文
Indexed By EI
Language 英语
Document Type 会议论文
Identifier http://dspace.imech.ac.cn/handle/311007/60162
Collection 高温气体动力学国家重点实验室
Recommended Citation GB/T 7714
Li XP,Wu K,Yao W,et al. A comparative study of highly underexpanded nitrogen and hydrogenjets using large eddy simulation[C]20th AIAA International Space Planes and Hypersonic Systems and Technologies Conference, 2015,2015.
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