中文摘要：

针对常用的锥型喷嘴在入口处能量损失大、寿命短问题,对传统喷嘴入口处的能量损失进行分析,建立喷嘴入口局部能量损失方程,提出一种入口带过渡段的新型喷嘴结构,利用数值模拟实验方法,结合3D-PIV测试技术对新型喷嘴流量系数及出口射流速度场进行测量。结果表明：新型喷嘴能有效降低入口能量损失;对于12.7 cm套管用喷嘴,过渡段倒角为45°、长度为2 mm的新型喷嘴性能最优;与传统喷嘴相比,新型喷嘴入口能量损失降低34%,剖面上下两端压差减少25%,流量系数提高8%,形成的射流轴线速度提高16%。

英文摘要：

In order to solve the problems of large energy loss at the entrance and the short service life of the commonly used cone nozzles,a local energy loss formula at the nozzle entrance was established through the analysis of the energy loss at the entrance. A new nozzle with transition section was designed on the basis of the established formula. Also,the flow coefficient and flow velocity field of this new nozzle were measured by using numerical simulation and 3D-PIV technique. The results show that the energy loss at the new nozzle entrance decreases efficiently. For a 12. 7 cm casing,the best nozzle has the following structures： the chamfer of transition section is 45° and the length is 2 mm. Compared with the commonly used nozzle,the energy loss at the new nozzle entrance decreases by 34%,the pressure difference between the up and down of entrance section reduces by 25%,the flow coefficient increases by 8%,and the flow axis velocity is improved by 16%.