涡轮叶栅尾缘喷气与主流掺混及干扰效应的机理研究

The effect of ejection from the symmetry slot of trailing edge for a turbine blade is investigated theoretically and experimentally . By means of numerical simulation codes, which is improved from a three-dimensional Navier-Stokes numerical program. A simple procedure to model the air ejection at trailing edge of the blade is presented, which is coupled correctly and effectively with the numerical solution of the main flow field. Some calculations with different ejection flow rate are performed by this program. The calculations show good agreement with test results and can be accepted by the engineering, especially for the total pressure loss, Mach number and outlet flow angle prediction. The effect of trailing edge ejection on the downstream flow field is discussed by means of wake shape, secondary flow structure and total pressure contour, etc. The main purpose of this research is to develop a useful numerical technique for understanding the complex mechanism of the trailing edge ejection and mixing process with the cascade main flow. Achvements obtained from this research is very useful to improve the present cooling technique for turbines of different type.

采用先进的测试手段和可视化技术捕捉喷射气流扩散掺混过程及其对主流场干扰效应，用实验和理论分析建立尾缘射流／主流掺混干扰模型并研究不同条件下冷气喷射对涡轮叶栅气动性能的影响。通过与实验比检验冷气喷射模型适用性及射流干扰效应，为从理论和实验上揭示射流与主流掺混和干扰的复杂过程机理提供科学依据。