预旋对迷宫密封内流动传热特性影响的研究  

A Study of the Influence of Inlet Pre-swirl on Flow and Heat Transfer Characteristics of a Labyrinth Seal

作　　者：晏鑫[1] 李军[1] 丰镇平[1] 

机构地区：[1]西安交通大学叶轮机械研究所,陕西西安710049

出　　处：《热能动力工程》2008年第1期7-10,共4页Journal of Engineering for Thermal Energy and Power

基　　金：国家重点基础研究计划(973)基金资助项目(2007CB707705);国家自然科学基金资助项目(50506023);新世纪优秀人才支持计划基金资助项目(NCET-07-0669)

摘　　要：采用三维周期性模型对发散型光滑面迷宫密封内传热及流动特性进行了研究,得出了两种流量下有无进口预旋时密封的间隙热系数随周向马赫数的变化关系,并与实验值、经验公式、二维轴对称模型得到的结果进行了比较,结果表明:该模型能较好地模拟有进口预旋时迷宫密封内的传热特性。在相同的流量和进口预旋比条件下,间隙热系数随转速的增加而增大;在相同流量和转速下,施加进口预旋能明显降低密封内总温升、减小间隙热系数,但不会影响子午面上的速度场;在相同转速和预旋比条件下,随着流量的增大,间隙热系数减小,子午面上速度增大,但流场结构不会发生变化。By adopting a three-dimensional periodical model,a study was conducted of the flow and heat transfer characteristics of a labyrinth seal with a transpiration-type smooth surface.As a result,obtained was the variation relationship of the windage-heat coefficient of the labyrinth seal with circumferential mach numbers under two different flow rates with and without an inlet pre-swirl.The relationship in question was compared with that obtained from experimental values,empirical formulae and two-dimensional axially-symmetric models.It has been found that the above model can simulate relatively well the heat transfer characteristics of the labyrinth seal incorporating an inlet pre-swirl.Under a same flow rate and same inlet pre-swirl ratio,the windage heat coefficient will increase with an increase of rotating speed.At a same flow rate and rotating speed,the imposition of an inlet pre-swirl can significantly lower the total temperature rise in the labyrinth seal and reduce the windage heat coefficient,but will not influence the velocity field on a meridian plane.Under the condition of a same rotating speed and inlet pre-swirl ratio,an increase of the flow rate will lead to a decrease of the windage heat coefficient and an increase of the velocity on a meridian plane.The structure of the flow field,however,will not change.

关 键 词：迷宫密封 进口预旋 间隙热系数 数值模拟 

分 类 号：TK124[动力工程及工程热物理—工程热物理]