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吸气式高超声速飞行器在飞行过程中受到大气紊流等外部干扰的作用时,飞行姿态很可能会出现大迎角情况。针对大迎角飞行时飞行器可能出现的气动问题,对一种典型吸气式高超声速飞行器的流场进行了数值模拟。以雷诺平均Navier-Stokes(RANS)方程为控制方程,采用标准k-ε湍流模型求解,得到其流场特征和气动特性。重点针对大迎角情况,分别对整机气动特性、进气道性能和全动尾翼气动性能进行了分析,并结合流场特征作出解释。结果表明,机身和发动机之间存在气动/推进耦合现象。大迎角下飞行器的气动参数表现出非线性特性,升阻比减小,整机纵向表现为静不稳定,且不稳定性随迎角增大而增大;进气道性能在大迎角下降低,从而导致发动机推力下降,不利于发动机的正常工作,但却适当降低了整机的纵向静不稳定度;全动尾翼操纵效率降低从而使得配平难度增大。
Aspiration hypersonic vehicles are subject to external disturbances such as atmospheric turbulence during flight, the flight attitude is likely to show a high angle of attack situation. In view of the possible aerodynamic problems of the aircraft at high angle of attack, the flow field of a typical aspirated hypersonic vehicle is numerically simulated. Using the Reynolds-averaged Navier-Stokes (RANS) equation as the governing equation, the standard k-ε turbulence model was used to solve the flow field characteristics and aerodynamic characteristics. Focusing on the situation of high angle of attack, the aerodynamic characteristics of intact air intakes, the performance of air intakes and the aerodynamic performance of full-tail are analyzed separately, and the characteristics of flow field are explained. The results show that there is aerodynamic / propulsive coupling between the fuselage and the engine. The aerodynamic parameters of the aircraft at high angle of attack showed nonlinear characteristics, the ratio of lift to drag was decreased, the longitudinal performance of the whole machine was static instability, and the instability increased with the angle of attack. The performance of the inlet at high angle of attack Lower down, resulting in decreased engine thrust is not conducive to the normal operation of the engine, but it is appropriate to reduce the machine’s longitudinal static instability; full-tail empennage manipulation efficiency is reduced so that the difficulty of increasing the trim.