摘要
对于高马赫数飞行器,其绕流场温度会急剧升高引发高温化学非平衡效应,进而影响边界层转捩过程。针对这一问题,一般需在基本流计算和稳定性分析中引入反映复杂物理化学过程的计算模型,但这制约了计算效率,且不同模型可能会得到不同的稳定性分析结果。为了进一步研究一些工程常用模型对计算的影响,本文发展了化学非平衡流动的线性稳定性分析方法,考察了化学非平衡效应对高焓钝楔边界层稳定性的影响途径,分析了不同热力学、输运系数和化学反应等物理化学模型造成的稳定性分析结果差异。研究表明:化学非平衡效应主要通过改变基本流影响模态N值,转捩预测时可以仅在基本流求解中考虑化学非平衡效应以提高计算效率;物理化学模型对第二模态的影响较小,对于由第二模态主导的转捩过程,预测结果对化学非平衡流动中物理化学模型的选取不敏感,但在第三模态对N值贡献较大时,模型选取对转捩预测结果的影响则无法忽略。
Boundary layer transition has a significant impact in the design of flight vehicles.At high Mach numbers,the temperature in the boundary layer rises rapidly,leading to a series of high-temperature effects,which affect the boundary layer transition process.Some physicochemical models are often introduced to reflect these effects in the numerical simulations,which greatly increases the computational cost.In the meantime,different models may give different results in the flow stability analysis.Currently,relevant research in this field is not sufficient,and the effects of typical physicochemical models have not been considered.In the present study,the linear stability theory(LST)for chemical non-equilibrium flow was developed,and the influence of chemical non-equilibrium effects on the flow stability of blunt wedge boundary layers was investigated.The differences in the boundary layer stability calculation results caused by physicochemical models such as the thermal models,the transport models,and the chemical models were analyzed.The results show that the chemical non-equilibrium effects mainly affect the N factors by changing the basic flow,thus,they can be considered merely in the basic flow calculation in order to improve the computational efficiency.The transition prediction result is insensitive to the selection of physicochemical models for second-mode dominant transition in the chemical non-equilibrium flow.However,when the contribution of the third mode to the N values is large,the influence of physicochemical model on the transition prediction cannot be ignored.
作者
李晨辉
万兵兵
涂国华
胡伟波
陈坚强
蒋崇文
LI Chenhui;WAN Bingbing;TU Guohua;HU Weibo;CHEN Jianqiang;JIANG Chongwen(School of Aeronautic Science and Engineering,Beihang University,Beijing 100191,China;State Key Laboratory of Aerodynamics,Mianyang 621000,China)
出处
《空气动力学学报》
CSCD
北大核心
2024年第12期12-24,I0001,共14页
Acta Aerodynamica Sinica
基金
国家自然科学基金(92052301,12002353,12202473)。
关键词
高焓边界层
流动稳定性
转捩预测
物理化学模型
化学非平衡效应
数值模拟
high-enthalpy boundary layer
flow stability
transition prediction
physicochemical models
chemical non-equilibrium effects
numerical simulation
