非对称安装布局下大型高超声速风洞引射增强型二次喉道数值优化

增强二次喉道扩压能力，降低接力引射器的引射流量是提高大型高超声速风洞运行经济性的重要技术措施。引射增压型二次喉道通过在二次喉道侧壁引射低总压介质增强其扩压能力，是一种非常有潜力的实用方案。本文通过数值模拟研究了其在长模型大攻角等非对称安装布局条件下的运行流场，并进一步优化了压力、介质类型等引射条件。结果表明，优化方案在高超声速风洞复杂运行条件下仍能保持较高的二次喉道扩压能力，较大幅度降低接力引射器的引射流量，具有可行性和实用性。

Numerical Optimization on Ejection-Supercharged Second Throat of Large Scale Hypersonic Wind Tunnel under Asymmetric Model Installation

In order to reduce the operation costs of large-scale supersonic wind tunnels, the authors of this article designed an adjustable secondary throat diffuser based on ejection of low total pressure air, and numerically verified its effectiveness under normal operating conditions. However, the practical wind tunnel operating conditions are more complicated, especially under the long model and high angle of attack installation conditions, the flow field may be severely distorted. In order to verify the effectiveness and practicability of the scheme under actual complex operating conditions, this paper further simulated the ejection diffusion flow field of the asymmetric installation of 3D model conditions, and optimized the ejection conditions including pressure and medium type. It is concluded that: (1) Under the conditions of the asymmetric installation of model, the test section of the supersonic wind tunnel has a relatively large flow separation zone and a distorted supersonic flow field, but the designed ejection-supercharged secondary throat diffuser scheme can still be started normally and worked in a positive state in pressure recovery augmentation. Under the same flow rate and total pressure, the scheme promotes the pressure recovery capacity of the diffuser section by 2.4 folds; (2) By appropriately increasing the total pressure of ejection while keeping the mass flow rate unchanged, the supersonic distortion flow field in the secondary throat diffuser can be actively corrected, and the pressure recovery capacity of the diffuser section can be further improved by 2.8 folds, and meanwhile, in case of higher cooling degrees, it can save 50%-60% of the ejector flow rate of the rear relay ejectors; (3) Under the same total pressure and geometry configuration conditions, replacing the working fluid of air with water vapor of 300 degree, it can not only maintain a high pressure recovery capacity of the diffuser section but also save nearly 80% of the ejection flow rate of the rear relay ejector with remove of water from primary flow by condensation, providing better practicability.