Abstract：Cavitation phenomenon in pipes with different length-diameter ratios and inclination angles is investigated. The cavitating flows in the pipes with 5 ∶1, 5 ∶2 length-diameter ratios, and 90°, 120°, 135° inclination angles are simulated under 0.3, 0.5, 1.0 MPa inlet pressure, respectively. The pressure and cavity contours are obtained. The simulation results show that all the cavity appears at the inlet of pipe. Under the same pressure differential across the pipe, the cavity size and intensity are shrunk and reduced with the increasing pipe diameter. Cavitation effect is remarked at 90° inclination angle, particularly a cavity appears each on the top and bottom of the pipe inlet edge. With the increasing inclination angle, the cavitation effect is weakened and the cavity size decreases; further it occurs at the bottom of the pipe inlet edge only. Meanwhile a few cavitation visualization experiments are carried out, indicting the numerical simulation results agree very well with the observations.
杜慧勇, 张青锋, 刘建新, 王站成, 李民, 徐斌. 不同长径比和倾角圆管道中的空化现象[J]. 排灌机械工程学报, 2015, 33(5): 412-416.
Du Huiyong, Zhang Qingfeng, Liu Jianxin, Wang Zhancheng, Li Min, Xu Bin. Cavitation in pipes with different length-diameter ratios and inclination angles. Journal of Drainage and Irrigation Machinery Engin, 2015, 33(5): 412-416.
[1]管金发, 邓松圣, 张攀锋, 等. 空化特性研究进展[J]. 科学技术与工程, 2011,11(27): 6674-6680. Guan Jinfa, Deng Songsheng, Zhang Panfeng, et al. Research progress of cavitation characteristics[J]. Science Technology and Engineering, 2011,11(27): 6674-6680.(in Chinese)[2]Aleiferis P G, Serras-Pereira J, Augoye A, et al. Effect of fuel temperature on in-nozzle cavitation and spray formation of liquid hydrocarbons and alcohols from a real-size optical injector for direct-injection spark-ignition engines[J]. International Journal of Heat and Mass Transfer, 2010,53(21/22):4588-4606.[3]Serras-Pereira J, Van Romunde Z, Aleiferis P G, et al. Cavitation, primary break-up and flash boiling of gasoline, iso-octane and n-pentane with a real-size optical direct-injection nozzle[J]. Fuel, 2010,89(9):2592-2607.[4]Javier López J, Salvador F J, De la Garza O A, et al. A comprehensive study on the effect of cavitation on injection velocity in diesel nozzles[J]. Energy Conversion and Management, 2012,64:415-423.[5]Payri F, Payri R, Salvador F J, et al. A contribution to the understanding of cavitation effects in diesel injector nozzles through a combined experimental and computational investigation[J]. Computers and Fluids, 2012,58:88-101.[6]Arcoumanis C, Flora H, Gavaises M, et al. Cavitation in real-size multi-hole diesel injector nozzles[C]//Proceeding of 2000 SAE World Congress. Detroit, USA:[s.n.], 2000:1-18.[7]Roth H, Giannadakis E, Gavaises M, et al. Effect of multi-injection strategy on cavitation development in diesel injector nozzle holes[C]//Proceeding of 2005 SAE World Congress. Detroit, USA:[s.n.], 2005:1-19.[8]Blessing M, König G, Krüger C, et al. Analysis of flow and cavitation phenomena in diesel injection nozzles and its effect oil spray and mixture formation[C]//Proceeding of 2003 SAE World Congress. Detroit, USA:[s.n.], 2003:1-15.[9]柏金. 柴油机喷嘴内空穴流动的数值模拟及试验研究[D]. 镇江: 江苏大学能源与动力工程学院, 2010.[10]孙剑. 柴油机喷油器喷孔内空化效应机理的研究[D]. 天津:天津大学动力机械及工程系, 2009.[11]付振, 李伟权, 许沧粟. 喷嘴内空穴现象对柴油机喷雾特性的影响[J]. 农机化研究, 2009,31(3):63-67. Fu Zhen, Li Weiquan, Xu Cangsu. Effect of cavitation inside the diesel nozzle on the spray characteristics[J]. Journal of Agricultural Mechanization Research, 2009,31(3):63-67.(in Chinese)[12]邹依琨. 柴油机喷油嘴内空穴流动数值模拟研究[D]. 南昌:南昌大学工程热物理系, 2009.[13]李翠, 厉彦忠. 低温流体经过弯管时的空化现象分析[J]. 低温工程, 2008(2):4-9. Li Cui, Li Yanzhong. Simulation and analysis on cavitating flow characteristics of liquid oxygen through elbow pipe[J]. Cryogenics, 2008(2):4-9.(in Chinese)[14]吴亚丹. 文丘里管内空泡及空泡群的演变及其溃灭特性[D]. 大连: 大连理工大学能源与动力学院, 2009.[15]何志霞, 黄云龙, 钟汶君, 等. 基于空穴初生的柴油机喷孔内部流动[J]. 江苏大学学报:自然科学版, 2011,32(6):672-677. He Zhixia, Huang Yunlong, Zhong Wenjun, et al. Flow in diesel nozzle holes based on initial cavitation[J]. Journal of Jiangsu University: Natural Science Edition, 2011,32(6):672-677.(in Chinese)[16]Margot X, Hoyas S, Fajardo P, et al. CFD study of needle motion influence on the exit flow conditions of single-hole injectors[J]. Atomization and Sprays, 2011,21(1):31-40.
