The aerodynamic aspects of indirect thrust measurement by the impulse method have been studied both experimentally and numerically. The underlying basic aerodynamic principle is outlined, the phenomena in subsonic, supersonic and arc-heated jets are explored, and factors affecting the accuracy of the method are studied and discussed. Results show that the impulse method is reliable for indirect thrust measurement if certain basic requirements are met, and a simple guideline for its proper application is given.
Cheng-Kang WuHai-Xing WangXian MengXi ChenWen-Xia Pan
Aeroheating prediction is a challenging and critical problem for the design and optimization of hypersonic vehicles.One challenge is that the solution of the Navier-Stokes equations strongly depends on the computational mesh.In this letter,the effect of mesh resolution on heat flux prediction is studied.It is found that mesh-independent solutions can be obtained using fine mesh,whose accuracy is confirmed by results from kinetic particle simulation.It is analyzed that mesh-induced numerical error comes mainly from the flux calculation in the boundary layer whereas the temperature gradient on the surface can be evaluated using a wall function.Numerical schemes having strong capability of boundary layer capture are therefore recommended for hypersonic heating prediction.
Quanhua Sun,~(a) Huiyu Zhu,Gang Wang,and Jing Fan Key Laboratory of High Temperature Gas Dynamics,Institute of Mechanics,Chinese Academy of Sciences, Beijing 100190,China