不同轮缘密封结构封严特性研究

Study on Sealing Characteristics of Different Rim Seal

主流的高温燃气在压力差的作用下通过涡轮动静叶之间的轮缘间隙入侵盘腔内部,造成涡轮盘过热。本文利用数值模拟计算方法,以1.5级涡轮为研究对象,研究了涡轮轴向轮缘密封、径向轮缘密封以及圆柱孔状径向轮缘密封结构的封严特性,分析了圆柱孔轴向位置和直径尺寸对轮缘燃气入侵和封严特性的影响。结果表明:数值计算得到的结果与实验值吻合良好,验证了所用数值方法的可靠性;径向轮缘密封相对于轴向轮缘密封在小冷气量工况时具有更好的封严性能,但在大冷气量工况下情况相反;当圆孔直径较大时,圆柱孔状径向轮缘密封可以改善传统径向轮缘密封在大冷气量工况下的封严性能,提高封严效率。

Under the action of the pressure difference,the mainstream high-temperature ingestion invades the interior of the disk cavity through the rim gap between the turbine rotor and stator.In this paper,taking 1.5-stage turbine as the research object,the sealing characteristics of turbine axial rim seal,radial rim seal and cylindrical hole radial rim seal are studied numerically.The influence of axial position and diameter of the cylindrical hole on mainstream ingestion and sealing performance are analyzed.The results show that the numerical calculation results are in good agreement with the experimental values,which verifies the reliability of the numerical method used.The radial rim seal has better sealing performance than the axial rim seal under small sealing flow conditions.However,the situation is reversed under large sealing flow conditions.When the diameter of the circular hole is large,the cylindrical hole radial rim seal can improve the sealing performance of the traditional radial rim seal under large sealing flow conditions,and improve the sealing effectiveness.