Transient numerical simulation of hemispherical cone with combined opposing jet in hypersonic flow

摘要

A novel combined opposing (CBO) jet is proposed in this study, which consists of a circle opposing (CO) jet and an annulus opposing (AO) jet. Three CBO jets with the internal diameters of AO jet D = 12, 16 and 20 mm in a free stream Mach number 10 at an altitude of 60 km are investigated by transient numerical method. The flow feature and the effects of heat reduction and drag reduction with CBO jet are explored in four pressure ratios (PR0.005, PR0.01, PR0.02 and PR0.05). In addition, the results are compared with those of conventional opposing (CVO) jet with single CO jet and the same effective jet area. The results show that the jet state of CBO jet is not only affected by PR but also affected by the interaction between the CO jet and AO jet. And the effects of heat reduction and drag reduction with CBO jet are better than that with CVO jet. Moreover, the position of AO jet in CBO jet can affect the aerodynamic heating and drag. The thermal protection effect of CBO jet with D = 20 mm is the best among three CBO jets. The heat reduction of CBO jet with D = 20 mm is 7.9%, 5.8% and 52.5% more than that of CVO jet in PRO.005, PR0.01 and PR0.02, respectively. And the drag reduction is 13.5% and 1.7% higher than that of CVO jet in the PR0.005 and PR0.01, respectively.