变来流马赫数条件下组合动力可调进气道流动特性初步研究

Preliminary Research on Turbine-Based Combined-Cycle Inlet Flow Characteristics at Variable Inflow Mach Number Conditions

采用动网格及非定常数值仿真方法,对组合动力进气道在变来流马赫数及变几何调节过程开展了数值模拟研究。数值仿真结果表明,随着来流马赫数的增加,进气道外压正激波从第二级压缩面向下游移动至贴近唇口位置,直至与喉道内结尾激波融合,处于内外混合压缩与结尾激波共同作用模式。在变几何调节过程中存在一定程度的压力波动现象,相比较而言,较高马赫数下,结尾激波更容易出现沿流道的前后振荡现象;进气道变马赫数、变几何调节过程中,进气道流量系数逐渐从0.53增大到0.93,总压恢复系数从0.95降低至0.43,静压比从3倍增大至58倍,在变几何调节过程中存在捕获流量波动现象,整体上与预期变化一致;在变马赫数模态转换过程中,进气道模态转换通过平动的方式实现流道切换,涡轮通道流量线性降低,冲压通道流量线性增大,且无明显激波振荡现象。

The aerodynamic characteristic of TBCC inlet at variable inflow Mach number and geometry inlet scheme is investigated based on dynamic mesh and unsteady numerical simulation methods.The results indicated that as inflow Mach number increased,terminal shock wave moved from second ramp to leading edge of cowl and then to throat section.The inflow is compressed by external and internal shock waves.The terminal shock is unsteady during the variable geometry and shock oscillation was obvious at high Mach number.As inflow Mach number increased,the variable geometry inlet capture mass flow ratio increased form 0.53 to 0.93,total pressure recovery decreased from 0.95 to 0.43,static pressure ratio increased from 3 to 58.Unsteady characteristics of flow ratio during variable geometry was consistent with the expected.Inlet mode transition was undertook at variable inflow Mach number through translation scheme.During this process,mass flow ratio of turbine flowpath decreased and ramjet flowpath increased linearly.Meanwhile,there is no obvious terminal shock oscillation.