论文部分内容阅读
针对高超声速二元进气道钝化唇缘位置可能出现的第Ⅳ类激波-激波干扰流动中的非定常振荡问题,采用基于有限体积方法结合网格自适应技术的VAS2D程序,数值求解二维可压缩层流Navier-Stokes方程,细致刻画了第Ⅳ类激波-激波干扰非定常流场中的复杂波系结构、壁面压力和热流分布,重点考察了入射激波位置、入射激波强度以及钝头体外形等对第Ⅳ类激波-激波干扰流动特性影响较为敏感的因素及其影响规律。数值模拟结果表明:第Ⅳ类激波-激波干扰流动可能出现非定常振荡,也可能呈现相对稳定的状态,入射激波条件和钝头体外形均可能对第Ⅳ类激波-激波干扰流动非定常性的显现及其振荡特征产生显著影响。采用无量纲的Strouhal数表征流动的非定常性,在文中数值模拟条件下,入射激波强度增大或者钝头体外形变钝,均会使得Strouhal数减小,而壁面热、力载荷有增大的趋势。合理地选择钝头体外形可望减小第Ⅳ类激波-激波干扰出现的比率,有效抑制流动中的非定常振荡现象,降低激波-激波干扰带来的热流和压力脉动峰值。
Aiming at the problem of unsteady oscillation of the fourth type of shock-shock interference flow in the hypersonic dual-inlet lip passivation lip position, the VAS2D program based on finite volume method combined with grid adaptive technique is adopted and the numerical solution Two-dimensional compressible laminar Navier-Stokes equations are used to describe the complex wave structure, wall pressure and heat flux in the quasi- Wave intensity and the shape of the blunt body on the fourth class of shock - shock wave interference characteristics of the more sensitive to the impact of factors and their laws. Numerical simulation results show that the fourth type of shockwave-shock interference flow may appear unsteady oscillation, and may also appear relatively stable state, the incident shock conditions and blunt body shape may be the fourth type of shockwave-shock interference Flow unsteady appearance and its oscillation characteristics have a significant impact. The non-dimensional Strouhal number is used to characterize the unsteady flow. Under the condition of numerical simulation, the Strouhal number decreases with the increase of the incident shock intensity or the dull shape of the blunt body, which leads to the increase of thermal and mechanical loads on the wall. the trend of. Reasonable choice of blunt body shape is expected to reduce the type Ⅳ shock - shock interference ratio appears to effectively inhibit the flow of unsteady oscillations and reduce shock-shock interference caused by heat flow and pressure pulsations peak.