论文标题
控制表面偏转引起的超音速流不稳定
Supersonic flow unsteadiness induced by control surface deflections
论文作者
论文摘要
超音速流中的控制表面部署具有许多应用，包括流量控制，混合和身体强度调节。控制表面偏转的程度引入了不同的流动不稳定。产生的流体动力学会严重影响下游流动特征和流体结构相互作用。 In order to understand the gas dynamics, an axisymmetric cylindrical body with a sharp-tip cone at zero angles of attack ($α=0^\circ$) is examined in a free stream Mach number of $M_\infty=2.0$ and Reynolds number of $Re_{D}=2.16 \times 10^6$ ($D=50$ mm).在基体周围考虑了四个静态控制表面偏转角（$θ=π/3，π/6，π/3，π/2 $，rad）。这些案例通过采用二维独立涡流模拟（DES）策略的商业流量求解器进行计算研究。再循环气泡长度，阻力系数的变化，壁静压统计，模型和周围环境上的声载荷，$ x-t $轨迹和$ x-f $频谱分析，模型上压力波动的相关系数以及模态分析，以了解流动不稳定。在$θ= [π/36] $时，控制表面后面的壁静压波动是最小且周期性的，仅声音载荷约为50 dB。在$θ= [π/2] $，一种暴力的周期性波动在控制表面周围各处爆发，导致较高的声音负载约为150 dB（比以前高3倍）。对于$θ= [π/6] $和$ [π/3] $，高频波动沿着重新连接的剪切层连续脱落，从而在控制表面唤醒中引起宽阔的光谱。
Control surface deployment in a supersonic flow has many applications, including flow control, mixing, and body-force regulation. The extent of control surface deflections introduces varying flow unsteadiness. The resulting fluid dynamics influence the downstream flow characteristics and fluid-structure interactions severely. In order to understand the gas dynamics, an axisymmetric cylindrical body with a sharp-tip cone at zero angles of attack ($α=0^\circ$) is examined in a free stream Mach number of $M_\infty=2.0$ and Reynolds number of $Re_{D}=2.16 \times 10^6$ ($D=50$ mm). Four static control surface deflection angles ($θ= π/36,π/6,π/3,π/2$, rad) are considered around the base body. The cases are computationally investigated through a commercial flow solver adopting a two-dimensional detached eddy simulation (DES) strategy. Recirculation bubble length, drag coefficient's variation, wall-static pressure statistics, acoustic loading on the model and the surroundings, $x-t$ trajectory and $x-f$ spectral analysis, pressure fluctuation's correlation coefficient on the model, and modal analysis are obtained to understand the flow unsteadiness. At $θ= [π/36]$, the wall-static pressure fluctuations behind the control surface are minimal and periodic, with a mere acoustic load of about 50 dB. At $θ= [π/2]$, a violent periodic fluctuation erupted everywhere around the control surface, leading to a higher acoustic load of about 150 dB (3 times higher than the previous). For $θ= [π/6]$ and $[π/3]$, high-frequency fluctuations with small and large-scale structures continuously shed along the reattaching shear layer, thereby causing a broadened spectra in the control surface wake.
