更泛空域、更宽速域的跨流域飞行器已成为当前研究的热点之一，乘波体因其高升阻比和简单外形受到了广泛关注和研究。目前对于高空稀薄条件下乘波体外形气动特性的研究还很少，由于流场包含从连续到稀薄多个流域，其气动特性预测面临严峻挑战。本文针对法国MARHy稀薄风洞测试的乘波体模型，采用直接模拟Monte Carlo (Direct Simulation Monte Carlo, DSMC)方法、传统的Navier-Stokes (NS)方程和基于DSMC数据改进的NS模型(DSMC data-improved Navier-Stokes，DiNS)进行模拟分析，通过与实验气动力测试结果对比评估了不同计算方法的计算精度，分析了近连续流条件下乘波体外形的气动力特点，研究了流场局部稀薄气体效应以及对气动力的影响，并进一步分析了马赫数和攻角的影响。结果表明：对于马赫数20、努森数0.01的乘波体实验工况，传统NS结合滑移边界预测的阻力与实验测量结果的相对误差高达39.19%，DiNS模型通过修正线性本构关系可将与实验的相对误差降低至3.95%；该乘波体外形摩阻占总阻比例达到97.14%，边界层中存在显著的剪切非平衡效应导致线性本构关系失效，使得NS预测的摩阻过高。此外，攻角的增加会使得升力系数显著增加，升阻比显著提高，同时稀薄气体效应更加显著；随着马赫数增加，该乘波体升力系数因偏离设计工况大幅度减小，升阻比显著下降。

Hypersonic vehicles in large airspace and wide speed range have become one of the current research hotspots, and waveriders have attracted significant attention due to their high lift-to-drag ratio and relatively simple shape. However, there is little research on the aerodynamic characteristics of waveriders under high-altitude rarefied conditions. Since the flow field encompasses multiple regimes ranging from continuum to rarefied, the accurate prediction of their aerodynamic characteristics remains a considerable challenge. This paper focuses on the rarefaction effect on aerodynamic characteristics of a waverider model, which is tested in the MARHy rarefied wind tunnel in France. Numerical simulations are performed using Direct Simulation Monte Carlo (DSMC) method, conventional Navier Stokes (NS) equations, and DSMC data improved Navier Stokes (DiNS) model. By comparing with experiment data, the computational accuracy of the different methods is evaluated. The aerodynamic characteristics of the waverider in the near-continuum regime are analyzed, with particular emphasis on the local rarefaction effects within the flow field and their influence on aerodynamic performance. Furthermore, the effects of Mach number and angle of attack are systematically investigated. The results show that under the experimental conditions of Mach 20 and Knudsen 0.01, the error in drag predicted by the conventional NS with slip boundary conditions reaches as high as 39.19% compared to experiment data. The DiNS model can reduce this relative error to 3.95% by correcting the linear constitutive relationship; For this waverider, skin friction contributes approximately 97.14% of the total drag. A pronounced shear nonequilibrium effect exists within the boundary layer, which invalidates the linear constitutive relations and causes the conventional NS equations to overpredict the skin friction. In addition, an increase in angle of attack leads to a significant increase in lift coefficient, a significant improvement in lift to drag ratio, and a more pronounced rarefaction effect; As the Mach number increases, the lift coefficient decreases significantly due to deviation from the design conditions, and the lift to drag ratio decreases significantly.