中文摘要：

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Navic-Stokcs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Stouhal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Srouhal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。

英文摘要：

Numerical simulations were carried out for the unsteady flow behavior of the hypersonic type IV shock-shock interactions acting on a blunt leading edge that represented the cowl of a tw o-dim ensional hypersonic inlet.T he com plex wave structures and surface heat flux/pressure created by the unsteady type IV shock-shock interactions w ere effectively captured by solving the lam inar com pressible N avier-Stokes equations via a tw o-dim ensional axisym m etric V ectorized A daptive Solver(V A S2D).T he V A S2D solver is based on an explicit finite volum e m ethod w ith an adaptive m esh technique and it has second order accuracy in both tim e and space.T he present sim ulations focus on the effects of the location and strength of the im pinging shock to g eth erw ith the geometry of the blunt bodyon the unsteady characteristics of interactions.T he results show that the flow can be either steady or unsteady depending on both the variations of the im pinging shock conditions and the blunt body geom etries.The unsteady characteristics of flowfield structure and surface p ressure/h eat flux are also sensitive tothe im pinging shock conditions.Sm all changes in the location or strength of the im pinging shockcan result in large changes in the unsteady behaviors of the flow and the surface pressure/heat flu x.T he Strouhal num ber was used to characterize the unsteady oscillation behavior U nder the conditions in the current w o rk,w ith the increases of the im pinging shock strength and the bluntness of the leading edge,the Strouhal num ber that is m ainly dependent on the standoff distance of the bow shock decreases,whereas the surface pressure/heat flux increase.Furthermore,properly choosing the geometry of the blunt body may greatly reduce the probability of the happening of the type IV shock-shock interactions,suppress the shock oscillation in the flow,and effectively reduce the peak value of the fluctuating surface heat flux and pressure loads distance of the bow shock decreases,whereas the surface pressure/heat