Recently, fluidic thrust vectoring control is popular for micro space launcher propulsion systems due to its several advantages, such as fast dynamic responsiveness, better control effectiveness, and no moving mechanical equipment. Counter-flow thrust vectoring control is an especially effective technique by utilizing less suction flow to control the mainstream deflection flexibly. In the current work, theoretical and numerical analyses are performed together to elaborate on the performance of the three-dimensional rectangular counter-flow thrust vectoring control system. A new propulsion nozzle of Mach 2.5 is devised by method of characteristics. To testify the feasibility and accuracy of the present research methodology, numerical results were validated against experimental data from the open literature. The computational result using the standard k-epsilon turbulence model reveals a good match with experimentally measured static pressure values along the centerline of the upper suction collar. The influence of several key parameters on vectoring performance is investigated herein, including the mainstream temperature, collar radius, horizontal collar length, and gap height. Critical parameters have been quantitatively analyzed, such as static pressure distribution along the centerline of the upper suction collar, pitching angle, suction mass flow ratio, and thrust coefficient. Furthermore, the flow-field features are qualitatively expounded based on the static pressure contour, streamline, iso-turbulent kinetic energy contour, and iso-Mach number contour. Some important conclusions are offered for further studies. The mainstream temperature mainly affects different dynamic characteristics of the mixing shear layer, including the convective Mach number of the shear layer, density ratio, and flow velocity ratio. The collar radius influences the pressure gradient near the suction collar surface significantly. The pitching angle increases rapidly with the increasing collar radius. As the horizontal collar length increases, the systematic deflection angle initially increases then decreases. The highest pitching angle is obtained for L/H = 3.53. With regard to the gap height, a larger gap height can achieve a higher pitching angle.

中文翻译：

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三维矩形逆流推力矢量控制的数值参数研究

近年来，流体推力矢量控制由于其动态响应速度快、控制效果更好以及无需移动机械设备等优点，在微型航天发射器推进系统中广受欢迎。逆流推力矢量控制是一种特别有效的技术，它利用较少的吸入流量来灵活控制主流偏转。在目前的工作中，理论和数值分析相结合，详细阐述了三维矩形逆流推力矢量控制系统的性能。根据特性方法设计了一种新的 2.5 马赫推进喷嘴。为了证明本研究方法的可行性和准确性，数值结果与来自公开文献的实验数据进行了验证。使用标准 k-epsilon 湍流模型的计算结果显示与实验测量的沿上吸入环中心线的静压值良好匹配。本文研究了几个关键参数对矢量性能的影响，包括主流温度、轴环半径、水平轴环长度和间隙高度。定量分析了沿上吸入环中心线的静压分布、俯仰角、吸入质量流量比和推力系数等关键参数。并根据静压等值线、流线、等湍动能等值线、等马赫数等值线对流场特征进行定性阐述。为进一步研究提供了一些重要结论。主流温度主要影响混合剪切层不同的动力学特性，包括剪切层的对流马赫数、密度比和流速比。轴环半径显着影响吸入轴环表面附近的压力梯度。俯仰角随着轴环半径的增加而迅速增加。随着水平轴环长度的增加，系统偏转角最初增加然后减小。L/H = 3.53 时获得最高俯仰角。关于间隙高度，较大的间隙高度可以实现更高的俯仰角。轴环半径显着影响吸入轴环表面附近的压力梯度。俯仰角随着轴环半径的增加而迅速增加。随着水平轴环长度的增加，系统偏转角最初增加然后减小。L/H = 3.53 时获得最高俯仰角。关于间隙高度，较大的间隙高度可以实现更高的俯仰角。轴环半径显着影响吸入轴环表面附近的压力梯度。俯仰角随着轴环半径的增加而迅速增加。随着水平轴环长度的增加，系统偏转角最初增加然后减小。L/H = 3.53 时获得最高俯仰角。关于间隙高度，较大的间隙高度可以实现更高的俯仰角。