超额定状态下二元超声速进气道的流动特性

为了揭示超额定工作状态下超声速进气道内的复杂流动机理，对一设计马赫数为2.0的二元超声速进气道开展了数值模拟研究，获得了其在不同来流马赫数状态、不同节流状态下的流场结构.结果表明:当进气道工作在额定状态时，随着节流程度的增加，其激波串的核心区由偏向下壁面摆至偏向上壁面；而在超额定状态下，由于依次受到唇罩内侧分离包、唇罩激波等的影响，激波串核心区则由偏向上壁面转而摆至偏向下壁面.在来流马赫数为2.5的节流状态下，其唇罩激波与前体斜激波相交形成了马赫杆等复杂波系结构，而来流马赫数为3.0状态却并未形成此类现象.在上述两种超额定工作状态下，前体斜激波的上透射激波均在高反压条件下演化为正激波形态，而唇罩激波的下透射激波形态也发生了明显的改变. 

Flow characteristics of a rectangular supersonic inlet under over-speed state

To aid in understanding the flow mechanism in supersonic inlet under the over-speed state,a numerical simulation was performed to obtain the flow structure of a rectangular inlet whose design Mach number was 2.0,operating under different inflow Mach numbers and backpressures.Results indicate:for the design case of Mach number 2.0,the core flow of shock train was deflected from the cowl-side surface to the ramp-side surface associated with the backpressure increase.While the inlet operated under the over-speed state,the core flow of shock train was deflected to the ramp-side surface firstly and then to the cowl-side surface due to the effects of the cowl-lip separation bubbles and the cowl shock in turn.For the case of inflow Mach number 2.5,a Mach-stem appeared at the joint point between forebody oblique shock and cowl shock once the backpressure increaseed to a certain value.However,this flow structure didn't appear in the case of inflow Mach number 3.0.Under the above two over-speed states,with the increase of backpressures,the transmit shock of forebody oblique shock was transformed into normal shock,and the transmit shock of cowl shock also changed its shape.