几何参数对带射流收缩型通道换热特性影响的液晶瞬态实验

Experiment of the effects of geometrical parameters on internalheat transfer in an impinging contraction channel with liquid crystal transient technique

采用窄带热色液晶全表面瞬态测温技术,对将涡轮发动机进气道支板的冲击腔进行放大和简化后所得的收缩型通道内表面开展冲击换热实验研究,具体考察了射流孔孔径、冲击距以及通道高度变化对努塞尔数分布及大小的影响.实验结果表明:孔径和通道高度的增大、冲击距的减小均使通道内部换热得以加强,但在侧壁和前缘的努塞尔数分布变化及平均努塞尔数增幅不尽相同;并且通道内部换热受孔径影响最大,受通道高度的影响最小.

An impinging heat transfer experiment in a contraction channel,obtained by simplifying and magnifying the strut in the inlet of a gas turbine engine,was carried out by adopting narrow-band thermochromic liquid crystal（TLC） transient measurement technique.The effects of the diameter of impingement hole,impingent distance and the height of the channel on Nusselt number distribution and quantities were studied.The results show that the heat transfer in the channel was enhanced with the increasing diameter of the impingent holes and the height of the channel,or the decreasing impingent distance.Meanwhile the distribution change of Nusselt number and the increase of mean Nusselt number on the sidewall and the leading edge are different.In addition,the primary dominating factor for the heat transfer in the channel is the diameter of the impinging holes,and the slightest factor is the height of the channel.