摘要
为评估孔型密封在液体透平机械动静间隙的封严效果,明确液体工质下孔型密封设计中关键几何参数孔深、孔径选取准则,采用基于动网格技术的网格自动生成方法和基于三维定常雷诺时均Navier-Stokes(RANS)方程的孔型密封泄漏流动数值计算方法,研究了液体工质下孔型几何参数孔深、孔径对孔型密封泄漏特性和转子耗功的影响规律。计算分析了2种转速(2000,6000 r/min)、5种孔径(3,6,9,12,16 mm)下孔深在0.5~15 mm范围连续变化时,液体孔型密封的泄漏量、转子耗功以及孔腔流场结构,并与实验结果进行了对比。结果表明:所采用的数值方法能够准确预测液体孔型密封泄漏量;液体孔型密封泄漏量随转速增大而线性减小;深径比(孔深与孔径之比)对孔腔内涡系结构具有显著影响,是影响液体孔型密封泄漏量的关键参数;随孔深径比增加,液体孔型密封泄漏量先减小后增大;存在最佳孔深径比范围0.5~0.6,此时液体孔型密封泄漏量最小;不同孔径下,液体孔型密封转子耗功随孔深径比的增加而急剧减小。
To evaluate the sealing performance of the hole-pattern seals in liquid turbomachines and provide a comprehensive selection criterion of the critical geometry parameters(hole depth and hole diameter)for the design of liquid hole-pattern seals,the mesh auto-generation method and numerical solution method for the prediction of the steady leakage flow in the hole-pattern seals were proposed and validated using the 3D steady Reynolds-averaged Navier-Stokes(RANS)equations.The influences of the hole depth and hole diameter on the seal leakage characteristics and rotor power loss were numerically investigated for a hole-pattern seal of water fluid.The leakage flow rate,rotor drag torque,and flow fields in the hole cavities were calculated and analyzed for liquid hole-pattern seals with various hole depths(H=0.5-15 mm)and five hole diameters(D=3,6,9,12,16 mm)at two rotational speeds(n=2000,6000 r/min).Numerical results show that the present numerical methods possess better accuracy for the prediction of leakage flow rate of the liquid hole-pattern seal.The leakage flow rate of the liquid hole-pattern seal decreases linearly with the rotational speed.From a view of seal leakage performance,the ratio of hole depth to hole diameter(A R),which significantly influences the structure of the vortex system in the hole cavity,is the most critical design parameter for liquid hole-pattern seals.With the increase of A R,the leakage flow rate firstly decreases and then increases.There is an optimum region for A R(0.5-0.6),where the liquid hole-pattern seal possesses the best sealing performance with minimum leakage.For the liquid hole-pattern seals with different hole diameters,the rotor power loss obviously decreases with the increase of A R.
作者
方志
李志刚
李军
FANG Zhi;LI Zhigang;LI Jun(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Collaborative Innovation Center of Advanced Aero-Engine,Beijing 100191,China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2020年第9期81-88,共8页
Journal of Xi'an Jiaotong University
基金
国家重点研发计划资助项目(2017YFB0601804)
国家自然科学基金资助项目(51776152)。
关键词
流体孔型密封
孔深
孔径
泄漏特性
转子耗功
liquid hole-pattern seal
hole depth
hole diameter
leakage characteristics
rotor power loss
