火星进入器壁面脉动压力环境数值模拟

为研究跨超声速阶段来流马赫数、来流攻角及配平翼展开角的变化对进入器壁面脉动压力环境的影响规律，本文采用脱体涡方法对火星进入器模型开展非定常数值模拟，获取壁面不同位置处的脉动压力信息。研究表明：在跨超声速阶段，进入器壁面脉动压力环境随马赫数的增加而趋于减缓。配平翼迎风面分离区受脱体激波影响明显，当来流马赫数较小时，可压缩效应较弱，分离区涡流运动剧烈，诱导的脉动压力环境较强；随着来流马赫数的增加，脱体激波对分离区抑制作用增强，分离区运动受到限制，诱导的脉动压力环境趋于平缓。此外，随着来流攻角增加，配平翼迎风面上再附点的位置向翼根方向转移，从而使翼根处的脉动压力环境趋于恶劣。当配平翼展开180°时，分离区再附点位置基本固定，配平翼迎风面脉动压力环境得到一定程度的减缓。功率谱分析表明，在配平翼迎风面上诱导的脉动压力能量主要集中在中低频区域。

Numerical Simulation of Fluctuating Pressure Environment of Mars Entry Capsule

Three-dimensional unsteady numerical simulations are performed to investigate the fluctuating pressure environment around a Mars entry capsule with different inflow Mach numbers, different inflow angles of attack and trim-flap of different unfolded angles. Based on the detached-eddy simulation method, the fluctuating pressure characteristics at different wall locations are obtained and analyzed. When the inflow Mach number increases from transonic to supersonic regime, the wall fluctuating pressure environment tends to be alleviated. The detached shock in front of the capsule base greatly affects the movements of the separation zone formed at the windward side of the trim-flap. When the transonic flow passes the capsule, the separation zone oscillates intensely, leading to a severe fluctuating pressure environment around the trim-flap. When the inflow Mach number increases, the movement of the separation at the trim-flap is partially inhabited, alleviating the pressure fluctuations. Moreover, when the flow angle of attack increases, the pressure fluctuations on the windward side of the trim-flap move to the flap-root. When the trim-flap unfolded at 180 degrees, the range of the separation zone and the location of the reattachment point are generally fixed, decreasing the local fluctuation intensity, and the spectrum of the fluctuating energy is concentrated at the moderate frequency.