旋转盘腔预旋角度的敏感性分析

采用单向FSI(fluid structure interaction)数值方法,研究转静系旋转盘腔进气预旋角度的变化对冷却效果的影响,并依据旋转盘腔冷却问题的工程评价体系对冷却效果进行评价.结果表明:当进气和旋转雷诺数均不变时,旋流比是进气预旋角度的单值函数.旋流比的改变能够使流动结构发生变化,影响盘面换热效果和转盘温度分布,导致与温度梯度相关的热应力也发生变化.随着旋流比的增加,旋转盘腔的流阻损失增大,迎风面平均换热效果呈现先减弱后增强的趋势,转盘整体应力水平上升,以及在盘心处的最大等效应力值增大.进气预旋角度的变化能够从部件承受能力和实际使用载荷两方面对涡轮盘的失效概率产生影响,因此,在涡轮盘腔设计阶段,需考虑预旋角度对涡轮盘安全性的影响. 

Sensibility analysis of inlet pre-swirl angle in the rotating cavity

Unidirectional FSI (fluid structure interaction) numerical method was applied to investigate the influence of the inlet pre-swirl angle on the cooling effect of the rotating cavity.And the cooling effect was evaluated by an engineering evaluation system,which includes resistance evaluation,heat transfer evaluation and stress distribution evaluation for the safety of the turbine disk.The results show that,the swirl ratio is a monotropic function of the inlet pre-swirl angle,while the inlet Reynolds number and the rotational Reynolds number are constant.The swirl ratio has a great influence on the fluid structure in the rotating cavity,which determines the heat transfer and temperature distribution of the rotating disk.Furthermore,the thermal stress of the rotating disk related to the temperature gradient could be affected.With the rise of the swirl ratio,the frictional windage of the rotating cavity increases,the heat transfer of the windward of the disk presents up-down tendency,the stress level and maximum value enlarge.Therefore,the change of the pre-swirl angle has an effect on the failure probability of the turbine disk from two aspects:material affordability and working stress.