直通篦齿封严结构压损规律和临界特性的研究

采用数值分析和实验相结合的方法,研究了直通篦齿封严结构齿间压力分布规律和临界特性.结果表明:采用重整化群k-ω湍流模型,计算与实验吻合较好;篦齿前后腔压比达到临界压比时,最后一级篦齿齿尖处流动达到堵塞状态,进一步增加压比,临界截面向来流方向移动,且实际流通面积增加,进而泄漏量增加;沿流动方向各齿造成的压力损失相同,齿间压力线性下降,齿间压力与进口总压比值曲线斜率的大小与进口总压有关. 

Numerical and experimental investigation of pressure loss and critical sealing characteristics of straight-through labyrinth seals

Numerical and experimental investigation of pressure loss and critical sealing characteristics of straight-through labyrinth seal has been made.The results show that the RNG k-ε turbulence model is suited to predict the flow of labyrinth seal.The flow of the last tooth is choked when the pressure ratio between the upstream and downstream of the labyrinth seal reaches a critical value.With the increase of the pressure ratio the critical cross moves towards the upstream of the last tooth and the true flow cross area is increased simultaneously,which leads to increase of the leakage.When the total pressure is fixed,the pressure distributed between the teeth decreases linearly along the flow direction and the slope of the curve of the ratio of the pressure between the teeth to the total pressure is related to the total pressure.