超声速进气道/风扇/外涵隔离段一体化稳态流动特性

Steady Flow Characteristics of Supersonic Inlet/Fan/Bypass Isolator Integration

摘要:

针对旋转爆震/涡扇组合发动机外涵隔离段与上下游部件(进气道/风扇/外涵隔离段)的匹配难题,利用分裂激盘模型对风扇进行简化,采用仿真方法开展马赫数为 3状态下进气道/风扇/外涵隔离段一体化定常流动特性与工作特性的研究。研究发现,进气道/风扇/外涵隔离段一体化流场节流过程中,进气道下游/风扇上游区域结尾激波串不断前移,结构形态呈现斜激波串形式,且结尾激波串外罩侧分离区尺度扩大,中心体侧的分离区则逐渐缩小直至基本消失；隔离段内流动始终保持亚声速状态,且马赫数逐渐降低。风扇的存在使进气道内分离区发生迁移和扩张,削弱了结尾激波的压升效应,同时导致低总压堆积在小半径区,而高总压区压力幅值下降,表现出不连续的特征。

Abstract:

Facing the difficulties in matching the bypass isolator with upstream and downstream components in the rotat-ing detonation/turbofan combined engine (inlet, fan, bypass isolator), the actuator disk model is used to simplify a fan model. Then the method of numerical simulation is used to carry out the study on steady flow characteristics and working characteristics of inlet/fan/ bypass isolator integration. It is found that during the throttling process of the integrated flow field of inlet/fan/ bypass isolator, in the zone downstream of the intake/upstream of the fan, the terminal shock wave con-stantly shifts forward, and its structure takes the form of oblique shock wave. Besides, the scale of separation zone on the cowl side expands, while on the center body side, the separation zone gradually shrinks until it basically disappears. Flow remains subsonic throughout the isolator and Mach number gradually decreases. The fan causes the separation zone of in-let to migrate and expand, weakening the pressure-rise effect of terminal shock wave, and leading to the accumulation of low-total-pressure in the small-radius zone and a decrease in the pressure amplitude in high-total-pressure zone, which ex-hibits a discontinuous character.