Hypervelocity imperfect gas nozzle design with shared wave-elimination contour

Abstract

A hypervelocity imperfect gas nozzle with a shared wave-elimination contour is designed by the residual correction method, allowing the test Mach number to be varied by changing the throat contours. Owing to imperfect gas effects, the nozzle designed by the classical method of characteristics with boundary layer correction does not produce a uniform flow field, resulting in significant deviation from the target Mach number. In this work, the computational fluid dynamics solver is used as an independent module without being coupled to the optimization code, reducing the design complexity. Designers can choose the appropriate solver according to the specified physical characteristics to consider imperfect gas effects. The Mach 15 hypervelocity nozzle designed by the residual correction method better eliminates the Mach waves and achieves a much higher flow uniformity than the nozzle designed by the classical method. On this basis, the dependence domain of the shared wave-elimination contour and the influence domain of the transonic solution are solved by the method of characteristics, and a replaceable throat contour is rigorously designed from aerodynamics theory. Quantitative evaluations show that the nozzles with a shared wave-elimination contour have the same level of flow uniformity, achieving high flow quality at Mach 13–15. The evaluation results validate the design's feasibility, supporting the future construction of hypervelocity tunnels.

Comparative Analysis of Supersonic Flow in Atmospheric and Low Pressure in the Region of Shock Waves Creation for Electron Microscopy

“…The chamber accommodates investigations under classical atmospheric conditions as well as in the low-pressure region at the boundary of continuum mechanics and the slip flow region ( Figure 2 ) [ 24 ]. The chamber is comprised of two chambers separated by a replaceable component, which can be used to separate the chambers with different aperture and nozzle variants according to the type of research currently planned [ 25 ]. In the paper, a variant is analyzed where the chambers are separated by the aperture with a diameter of 1.6 mm and a subsequent nozzle with dimensions that are further determined in the paper according to the theory for the calculated cross-section.…”