Design And Analysis Of Hypersonic Inlet With Integrated Bump/Forebody

In this paper,the mechanism of supersonic Bump is introduced to the hypersonic inlet to improve the performance of inlet.However,adding the Bump to the hypersonic inlet directly will cause serious flow loss,so the method of Bump/forebody integration is applied in the hypersonic inlet.First,the method of hypersonic inlet Bump/forebody integration is consists of two parts,the flow field in osculating plane and osculating planes distribution along transverse direction.The flow field in osculation plane can be divided into two parts,the shock-dependent area and the main compression area.The main compression area is composed of a cluster of Mach waves.Each Mach wave is designed by method of charateristics,bisection method is used to adjust the static pressure of the wall to control the amount of compression.The flow fields in osculating plane with different compression amount are set along transverse direction,thus a slim and integrated Bump is formed on the forebody.Secondly,the performances of the hypersonic inlet with integrated Bump/forebody are studied by numerical simulation and wind tunnel tests.Numerical results show that the Bump/forebody integration does not change the aerodynamic performance of the inlet basically at design Mach number;the modified inlet has almost the same drag performance as the original inlet,and even slightly better;but the modified inlet achieves the obvious diversion of the low-speed flow.Besides,the integrated Bump/forebody is also beneficial to the starting.In the study of the starting performance,it is found that the Bump/forebody integration makes the self-starting performance better,ability of maintaining the starting stronger,the hysteresis loop smaller.These features have greatly improved starting performance.During the starting process,the shape of separation zone is rebuilt by the modified forebody surface which makes the spillage much easier.Then,the experiments of the self-starting angle of attack and self-unstarting angle of attack are done.It is show that the results obtained by wind tunnel test are almost the same with the numerical results,which indicates that the numerical simulation method adopted in this paper is reliable.Finally,inlets with different Bump surface and Bump height are studied based on the method of the hypersonic inlet with integrated Bump/forebody respectively.In the study of Bump surface along transverse direction,it is show that Bump surface changes the starting performance greatly.In the Bump height study,it is found that increasing the height is beneficial to the starting.By analyze the shape of the separation zone,it is found that with the Bump height increases,the separation zone transition from arch-shape to wave-shape.Besides,the open separation zone and the closed separation zone are defined according to the characteristics of the separation zone.It is found that when closed separation zone is formed,inlet starts at a Mach number higher than the design point,which should be avoid in inlet design.