二维可压缩流动抽吸流量模型及验证

根据超声速与亚声速流动的特征,依据Prandtl-Meyer膨胀波理论,根据背压与来流静压确定膨胀波后的马赫数,获得了质量抽吸流率,并导出了壅塞发生的条件,建立了二维超声速抽吸模型;根据冲量定理,假定气体从主流区域到抽吸腔流态的变化是由于压差的冲量作用,建立了亚声速抽吸模型,并且进一步阐述了亚声速抽吸壅塞发生的机制。计算流体力学验证表明亚声速抽吸冲量模型的偏差较大,因此通过数值拟合模型来描述亚声速抽吸流动。该研究为三维抽吸研究提供了参考。

Model and validation of two-dimensional compressible bleed flow

According to the characteristics of supersonic and subsonic flow, the Mach number after expansion waves is determined by the back pressure and static pressure based on Prandtl-Meyer theory, and bleed mass flow rate is obtained. Further the conditions for the occurrence of choking were derived, so a two-dimensional supersonic bleed model is established. According to the impulse theorem, it is assumed that the state change of gas from the main flow to the bleed chamber is due to the impulse of the differential pressure, based on this assumption, a subsonic bleed model is established and the mechanism of subsonic bleed chocking is revealed. CFD verifications show that the subsonic bleed impulse model has a big departure, so subsonic bleed flow is described by a numerical fitting model. This study provides a reference for three-dimensional bleed research.