旋流和风阻温升下压气机级间篦齿封严空气网络计算模型

Network model for calculation of labyrinth seal in compressor stator well with swirl flow and windage heating

以压气机级间篦齿封严结构为研究对象,将封严系统简化为典型元件组成的空气网络,建立相应的元件流动特性计算模型。篦齿封严泄漏特性计算模型中没有考虑旋流和风阻温升影响的问题。特别采用一维流基本方程组进行描述旋转盘腔内的旋流,转子壁面摩阻应用经验关系式计算,方程组采用龙格-库塔法求解。旋转盘腔一维工程计算获得其旋流速度和风阻温升分布。根据旋流速度的大小,采用面积修正法对篦齿封严的泄漏特性计算方法进行了修正,并通过考虑流体物性随沿程温度变化来考虑风阻温升的影响。考虑旋流与温升的泄漏流量计算结果与数值计算结果最大相差1.4%,而不考虑旋流及风阻温升时最小偏差为9.9%,最大偏差为20.1%。一维工程计算结果与实验结果进行了对比,两者吻合良好,相对偏差不超过7%。计算中采用实测的篦齿间隙,该间隙通过在旋转篦齿实验中测量转子的转动变形与受热膨胀,以及机匣的热变形而获得。

The labyrinth seal in a compressor stator well was simplified to one-dimensional network model consisting of typical elements.Then the computational models for these elements were built.The present model for the leakage calculation of labyrinth seal didnt consider swirl flow and windage heating impacts.One-dimensional basic equations were used to describe the swirl flow in rotating disc cavity.And empirical correlations were used to calculate the rotor wall friction.Runge-Kutta method was employed to solve these equations about circumferential velocity and windage heating of the rotating flow.An area correction method with swirl flow was adopted,and windage heating made the change of airflow properties.The relative deviation of leakage flow rate result of one-dimensional network and CFD was less than 1.4% with swirl flow and windage heating.Without swirl flow and windage heating,the relative deviation was more than 9.9% and less than 20.1%.Compared with the experimental results,the one-dimensional network calculation results agreedwell with each other,the relative deviation was no more than 7%.one-dimensional network calculation took the practical working tip clearance of the labyrinth seal.In rotating labyrinth seal experiment,the practical clearance was obtained by measuring the radial displacement of rotor caused by rotation and thermal deformation as well as the radial displacement of casing caused by thermal deformation.