发表机构
Universitat Politècnica de Catalunya–BarcelonaTech (UPC); European Space Agency (ESA), European Space Research and Technology Centre (ESTEC)（加泰罗尼亚理工大学; 欧洲空间局（ESA）欧洲空间研究与技术中心（ESTEC））
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究采用直接模拟蒙特卡罗方法，考察稀薄高超声速流过40°倾斜平板时，气体-表面散射定律通过分子碰撞对入射分子群体的反馈效应，评估Maxwell与CLL散射模型，发现群体反馈与力的投影决定散射响应在宏观量中的增强、掩盖或反转。
AI 中文摘要
通过分子间碰撞，气体-表面散射定律能够重塑其所作用的入射分子群体。我们使用直接模拟蒙特卡罗方法，在跨越0.023≤Kn∞≤8.439的四个基准条件下，对40°倾斜平板后的高超声速流动进行了这一反馈的检验。通过固定入射的矩参考以及在同一记录的非反应性入射群体上评估替代核，对Maxwell和Cercignani-Lampis-Lord（CLL）散射进行了评估。在Kn∞=0.023时，Maxwell剪切和热传递偏离漫反射-镜面端点插值达其漫反射参考值的40%。在尾迹区域，由降低的切向CLL适应引起的群体变化推翻了剪切和 translational 热传递的固定入射减少。在两个最高条件下，CLL动量响应变得几乎逐分量，产生在阻力-升力平面中几乎正交的位移。然而，跨壁面定律的常见入射所需的总能量约束在Kn∞=8.439时保留了漫反射热传递系数的3.1%的缺陷。因此，选定响应关系的恢复并不确立常见入射或自由分子流。冷束对称性使得升力在法向和切向CLL适应系数交换下不变，但阻力并非如此。这为模拟的不对称情况提供了一个限制性解释：在Kn∞=8.439时，它们产生几乎相等的升力，而其中一个产生66%更多的阻力。因此，群体反馈和力的投影决定了条件散射响应在宏观可观测量中被增强、掩盖还是反转。
英文摘要
Through intermolecular collisions, a gas-surface scattering law can reshape the incident molecular population on which it acts. We examine this feedback using direct simulation Monte Carlo for hypersonic flow past a $40^\circ$ inclined flat plate at four benchmark conditions spanning $0.023\leq Kn_\infty\leq8.439$. Maxwell and Cercignani-Lampis-Lord (CLL) scattering are assessed through fixed-incidence moment references and evaluation of alternative kernels on the same recorded non-reactive incident populations. At $Kn_\infty=0.023$, Maxwell shear and heat transfer depart from diffuse-specular endpoint interpolation by up to $40\%$ of their diffuse-reference values. In the trailing patch, the population change induced by reduced tangential CLL accommodation overturns the fixed-incidence reductions in both shear and translational heat transfer. At the two highest conditions, the CLL momentum responses become nearly componentwise, producing nearly orthogonal displacements in the drag-lift plane. Nevertheless, a total-energy constraint required by common incidence across wall laws retains a defect of $3.1\%$ of the diffuse heat-transfer coefficient at $Kn_\infty=8.439$. Recovery of selected response relations therefore does not establish common incidence or a free-molecular flow. A cold-beam symmetry makes lift invariant under exchange of the normal and tangential CLL accommodation coefficients, but not drag. This provides a limiting explanation for the simulated asymmetric cases: at $Kn_\infty=8.439$, they yield nearly equal lift while one produces $66\%$ more drag. Population feedback and force projection thus determine whether the conditional scattering response is reinforced, obscured or reversed in the macroscopic observables.
Comments48 pages, 14 figures, 11 tables. Data, code and movies: https://doi.org/10.5281/zenodo.21360802
