To aim at design requirements of high lift-to-drag ratio as well as high volumetric efficiency of next generation hypersonic airplanes,a body-wing-blending configuration with double flanking air inlets layout is prese...To aim at design requirements of high lift-to-drag ratio as well as high volumetric efficiency of next generation hypersonic airplanes,a body-wing-blending configuration with double flanking air inlets layout is presented.Moreover,a novel forebody design methodology which by rotating and assembling two waverider-based surfaces is firstly introduced in this paper.Some typical configurations are designed and their aerodynamic performances are evaluated by computational fluid dynamics.The results for forebodies analysis show that large volumetric efficiency,high lift-to-drag ratio,and uniformly distributed flowfield at the inlet cross section can be assured simultaneously.Furthermore,results of numerical simulation of four integrated configurations with various leading edge shapes,including three power-law curves and a cosine curve clearly show the advantage of high lift-to-drag ratio.Besides,the high pressure generated by the side wall of the airframe can be partly captured by the reasonably designed wings in the condition of small flight attack angle.Then the order of lift-to-drag ratio of four configurations at 0 degree flight attack angle is completely different from the condition of 4-degree flight attack angle.This result demonstrates that the curve shape of the leading edge is very important for the lift-to-drag ratio of the aircraft,and it should be further optimized under the cruising attack angle in future work.展开更多
The optimization of 2D expansion lines and key parameters of three-dimensional configurations was carried out under simulated conditions of Mach 6.5 and a flight altitude of 25 km for an integrated configuration of th...The optimization of 2D expansion lines and key parameters of three-dimensional configurations was carried out under simulated conditions of Mach 6.5 and a flight altitude of 25 km for an integrated configuration of the afterbody/nozzle of a hypersonic vehicle.First,the cubic B-spline method was applied to parameterize the expansion lines of the upper expansion ramp.The optimization procedure was established based on computational fluid dynamics and the sequential quadratic programming method.The local mesh reconstruction technique was applied to improve computational efficiency.A three-dimensional integrated configuration afterbody/nozzle was designed based on the two-dimensional optimized expansion lines.The influence rules incorporated certain key design parameters affecting the lift and thrust performance of the configuration,such as the ratio of the lengths of the lower expansion ramp to the afterbody (l/L),the dip angle of the lower expansion ramp ω,and the ratio of exit height to the length of afterbody (H/L).Under these conditions,we found that the integrated configuration has optimal performance when l/L=1/6,H/L=0.35 and =10°.We also showed that the presence of a side-board promotes lift and thrust performance,and effectively prevents the leakage of high pressure gas.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 90916013)the guidance and help from Academician Li Tian and peer reviewers are gratefully acknowledged
文摘To aim at design requirements of high lift-to-drag ratio as well as high volumetric efficiency of next generation hypersonic airplanes,a body-wing-blending configuration with double flanking air inlets layout is presented.Moreover,a novel forebody design methodology which by rotating and assembling two waverider-based surfaces is firstly introduced in this paper.Some typical configurations are designed and their aerodynamic performances are evaluated by computational fluid dynamics.The results for forebodies analysis show that large volumetric efficiency,high lift-to-drag ratio,and uniformly distributed flowfield at the inlet cross section can be assured simultaneously.Furthermore,results of numerical simulation of four integrated configurations with various leading edge shapes,including three power-law curves and a cosine curve clearly show the advantage of high lift-to-drag ratio.Besides,the high pressure generated by the side wall of the airframe can be partly captured by the reasonably designed wings in the condition of small flight attack angle.Then the order of lift-to-drag ratio of four configurations at 0 degree flight attack angle is completely different from the condition of 4-degree flight attack angle.This result demonstrates that the curve shape of the leading edge is very important for the lift-to-drag ratio of the aircraft,and it should be further optimized under the cruising attack angle in future work.
基金supported by the National Natural Science Foundation of China (90916013)
文摘The optimization of 2D expansion lines and key parameters of three-dimensional configurations was carried out under simulated conditions of Mach 6.5 and a flight altitude of 25 km for an integrated configuration of the afterbody/nozzle of a hypersonic vehicle.First,the cubic B-spline method was applied to parameterize the expansion lines of the upper expansion ramp.The optimization procedure was established based on computational fluid dynamics and the sequential quadratic programming method.The local mesh reconstruction technique was applied to improve computational efficiency.A three-dimensional integrated configuration afterbody/nozzle was designed based on the two-dimensional optimized expansion lines.The influence rules incorporated certain key design parameters affecting the lift and thrust performance of the configuration,such as the ratio of the lengths of the lower expansion ramp to the afterbody (l/L),the dip angle of the lower expansion ramp ω,and the ratio of exit height to the length of afterbody (H/L).Under these conditions,we found that the integrated configuration has optimal performance when l/L=1/6,H/L=0.35 and =10°.We also showed that the presence of a side-board promotes lift and thrust performance,and effectively prevents the leakage of high pressure gas.
