STF动态插入件对管内紊流强化换热的研究

ENHANCING TURBULENT HEAT TRANSFER IN TUBE BY THE STF INSERT

利用STF元件(后掠梯形一旗形插入件)的自激振荡组件系统特性和有限翼展机翼特性进行了管内紊流强化换热的研究。实验表明:STF元件具有比RF元件(矩形旗形插入件)更显著的强化换热净效益,BSTF元件(双边后掠梯形一旗形插入件)的阻力损失与RF元件相差不大,换热系数增加却比RF元件高出近一倍。实验和分析都表明,后掠角β对换热系数和阻力损失的增加产生较大影响。在后掠角β=75.9°～77.3。范围内,STF元件可获得最大强化换热净效益。

STF (Sweptback Trapezoid Flag) type dynamic insert in the characters of self excitation oscillation and finite span wing is used to enhance the turbulent heat transfer. Experiments indicate that the net benefit of heat transfer by STF insert is more obvious than that by RF(Rectangule Flag)type insert; by using BSTF (Bificial STF) insert, the pipe resistance loss is near to that by RF insert, but the increase of heat transfer coefficient is twice as large as that by RF insert. The sweptback angle β considerably affects heat transfer coefficient and resistance loss, and best net benefit of heat transfer can be obtained under the condition that the β equals 75.9°～77.3°.