CAJ | 학술논문

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%。
침대상용적추형분취재입구처능량손실대、수명단문제，대전통분취입구처적능량손실진행분석，건립분취입구국부능량손실방정，제출일충입구대과도단적신형분취결구，이용수치모의실험방법，결합3D-PIV측시기술대신형분취류량계수급출구사류속도장진행측량。결과표명：신형분취능유효강저입구능량손실；대우12.7 cm투관용분취，과도단도각위45°、장도위2 mm적신형분취성능최우；여전통분취상비，신형분취입구능량손실강저34%，부면상하량단압차감소25%，류량계수제고8%，형성적사류축선속도제고16%。
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 fol-lowing 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%.