We investigate supersonic flow over rectangular cavities of 3 different length-to-depth ratio (L/D ) – 3, 4.5, and 6. Half of the length of the cavities will be covered additional lids of D/d = 6, in which D/d is the ratio of cavity depth to lid thickness. The lids were installed to either leading edge (FP), trailing edge (BP), or both edges (CP) of the cavities, resulting in 12 variety of cavity configurations. Validation study was performed beforehand to ensure the reliability of Scaled Adaptive Simulation (SAS) turbulence model for supersonic cavity flow simulation in 2-dimensional (2D) domain. Subsequently, pressure fluctuation on cavity floor was obtained through numerical simulation on each cavity model and its frequency response was analysed. The use of partial cover was found to shorten the length of shear layer, which in turn caused mode switching in dominant cavity tones and various changes in mean pressure distribution. Furthermore, certain flowfield characteristics of partially covered cavities were also identified, depending on partial cover configuration and cavity length. These characteristics are also similar to those previously observed in subsonic partially covered cavity flow.
展开▼
机译：我们研究了3种不同的长深比（ L / D）– 3、4.5和6的矩形腔上的超音速流动。腔的一半长度将被覆盖另外的 D / d ＝ 6，其中D / d是空腔深度与盖厚度之比。将盖子安装到型腔的前缘（FP），后缘（BP）或两个边缘（CP），产生12种不同的型腔配置。事先进行了验证研究，以确保二维（2D）域中超声速腔流模拟的比例自适应模拟（SAS）湍流模型的可靠性。随后，通过对每个腔体模型的数值模拟来获得腔体底部的压力波动，并对其频率响应进行分析。发现使用部分覆盖物缩短了剪切层的长度，这又导致了主导空腔音调的模式转换以及平均压力分布的各种变化。此外，还根据部分覆盖物的构型和腔体长度确定了部分覆盖的腔体的某些流场特性。这些特征也类似于先前在亚音速部分覆盖腔流中观察到的特征。
展开▼
