EXPERIMENTAL INVESTIGATION ON DYNAMIC CHARACTERISTICS OF LIQUID NITROGEN SINGLE BUBBLE IN THE FREE FIELD
-
摘要: 本文专门设计搭建了低温介质空泡演化实验测试平台, 对液氮单空泡非定常演化过程和动力学特性开展了实验研究. 实验中利用电火花瞬态放电激发液氮汽化形成单空泡, 通过高速摄影系统对单空泡的瞬态特征进行了精细化捕捉. 为了进一步揭示低温介质独特的物理性质以及强热力学效应对单空泡演化过程的影响机制, 对比分析了在相同环境压力下, 77.41 K液氮和298.36 K水单空泡的演化过程和动力学特性. 基于实验得到空泡半径与界面速度等定量数据, 阐明了液氮单空泡球形与非球形演化阶段的非定常特性. 研究结果表明: (1) 在相同输入电压下, 液氮单空泡的整体尺寸比常温水更小, 当输入电压为400 V时, 液氮空泡的最大半径约为常温水空泡的0.69倍; 同时, 液氮单空泡经历了膨胀阶段−收缩阶段−振荡阶段以及上升阶段的演化过程. (2)液氮空泡的收缩过程主要由相界面的热传导主导, 没有明显的塌陷现象, 收缩阶段液氮空泡的最小收缩半径约为常温水的5.5倍. (3)在液氮空泡振荡初期, 空泡相界面传热增强, Rayleigh-Taylor不稳定与热力学效应共同引起了空泡界面的表面粗化效应; 在整个振荡阶段, 空泡界面附近存在破碎的小泡. 当输入电压较高时, 空泡底部的小泡数量显著增多. (4)由于液氮空泡浮力系数较大, 液氮空泡在演化后期空泡整体向上迁移显著, 液氮空泡底部收缩更快产生凹陷, 促使空泡变为环状.Abstract: The objective of this paper is to investigate the transient evolution and dynamic characteristic of liquid nitrogen single bubble. In the experiment, electric spark transient discharge (EDM) was used to stimulate the evaporation of liquid nitrogen to form a single bubble, and the evolution process of the single bubble was captured by a high-speed camera with high resolution. In order to further reveal the unique physical properties of low-temperature media and the strong thermodynamic effects on the evolution of the single bubble, the unsteady evolution process and dynamic characteristics of single bubble in liquid nitrogen at 77.41 K and water at 298.36 K under the same ambient pressure were analyzed. And quantitative data such as the radius of bubble and interfacial velocity were obtained experimentally to elucidate the unsteady characteristics of the spherical and non-spherical evolution of liquid nitrogen single bubble. The results show that (1) the size of a single bubble in liquid nitrogen is smaller than that of ambient water at the same input voltage. The maximum radius of the liquid nitrogen bubble is about 0.69 times that of the ambient water bubble, when the input voltage is 400. The evolution of a single bubble in liquid nitrogen experiences an expansion stage, a contraction stage, an oscillation stage, and a up phase, respectively. (2) The shrinkage stage of liquid nitrogen vacuoles is mainly dominated by the heat conduction at the phase interface, and there is no obvious collapse phenomenon. The minimum radius of liquid nitrogen bubble is about 5.5 times bigger than that of the ambient water bubble during the shrinkage stage. (3) The heat transfer at the phase interface is enhanced during the early stage of the oscillation stage, the surface roughening effects is amplified over the bubble surface resulting from Rayleigh-Taylor instability coupled with the thermal effects. And small broken bubbles exist near the bubble surface during the oscillation stage. When the input voltage is higher, the number of small bubbles at the bottom of the vacuole increases significantly. (4) Due to the large buoyancy coefficient of the liquid nitrogen bubble, the overall upward migration of liquid nitrogen bubble is significant in the late stage of liquid nitrogen. The bottom of the liquid nitrogen vacuole shrinks more quickly to create a depression, driving the vacuole to into a ring shape.
-
Key words:
- liquid nitrogen /
- single bubble /
- dynamic characteristics /
- experimental observation
-
图 1 低温介质单空泡演化观测实验平台总体示意图(左)和实物图(右) (1.实验罐 2.真空隔热层 3.真空泵 4.高速相机5.电火花空泡发生器6. LED灯 7.柔光布 8.真空罐 9.电脑 10.低温电极)
Figure 1. Schematic (left) and physical (right) picture of cryogenic single bubble test rig (1. test tank 2. vacuum insulation chamber 3. vacuum pump 4. high speed camera 5. bubble generator 6. LED lamp 7. frosted glass 8. vacuum tank 9. computer 10. vacuum electrodes)
表 1 输入电压400 V时实验参数与实验结果
Table 1. Experimental conditions and results when the input voltage is 400 V
Case Temperature
Tl/KPressure
pair/kPaVapor pressure
pv/kPaDensity
ρ/(kg·m−3)Maximum radius
Rm/mmVertical distance
h/mmwater 298.36 118.325 3.21 996.95 13.76 100 liquid
nitrogen77.41 118.325 101.98 806.38 9.48 100 -
[1] Brennen CE. Cavitation and Bubble Dynamics. Oxford: Oxford University Press, 1995 [2] 季斌, 程怀玉, 黄彪, 罗先武, 彭晓星, 龙新平. 空化水动力学非定常特性研究进展及展望. 力学进展, 2019, 49: 201906 doi: 10.6052/1000-0992-17-012Ji Bin, Cheng Huaiyu, Huang Biao, Luo Xianwu, Peng Xiaoxing, Long Xinping. Research progresses and prospects of unsteady hydrodynamics characteristics for cavitation. Advances in Mechanics, 2019, 49: 201906 (in Chinese) doi: 10.6052/1000-0992-17-012 [3] Huang B, Young YL. Combined experimental and computational investigation of unsteady structure of sheet/cloud cavitation. Journal of Fluids Engineering, 2013, 135(7): 071301 doi: 10.1115/1.4023650 [4] Fan YD, Chen TR, Liang WD, et al. Numerical and theoretical investigations of the cavitation performance and instability for the cryogenic inducer. Renewable Energy, 2022, 184: 291-305 doi: 10.1016/j.renene.2021.11.076 [5] 王一伟, 黄晨光, 杜特专, 方新, 梁乃刚. 航行体垂直出水载荷与空泡溃灭机理分析. 力学学报, 2012, 44(1): 39-48 doi: 10.6052/0459-1879-2012-1-lxxb2011-139Wang Yiwei, Huang Chenguang, Du Tezhuan, Fang Xin, Liang Naigang. Mechanism analysis about cavitation collapse load of underwater vehicles in a vertical launching process. Chinese Journal of Theoretical and Applied Mechanics, 2012, 44(1): 39-48 (in Chinese) doi: 10.6052/0459-1879-2012-1-lxxb2011-139 [6] Hung CF, Hwangfu JJ. Experimental study of the behaviour of mini-charge underwater explosion bubbles near different boundaries. Journal of Fluid Mechanics, 2010, 651: 55-80 [7] Zhang AM, Wang SP, Huang C, et al. Influences of initial and boundary conditions on underwater explosion bubble dynamics. European Journal of Mechanics, B/Fluids, 2013, 42: 69-91 doi: 10.1016/j.euromechflu.2013.06.008 [8] Pröbsting S, Yarusevych S. Laminar separation bubble development on an airfoil emitting tonal noise. Journal of Fluid Mechanics, 2015, 780: 167-191 [9] 程怀玉, 季斌, 龙新平, 槐文信. 空化对叶顶间隙泄漏涡演变特性及特征参数影响的大涡模拟研究. 力学学报, 2021, 53(05): 1268-1287 doi: 10.6052/0459-1879-20-415Cheng Huaiyu, Ji Bin, Long Xinping, Huai Wenxin. LES investigation on the influence of cavitation on the evolution and characteristics of tip leakage vortex. Chinese Journal of Theoretical and Applied Mechanics, 2021, 53(5): 1268-1287 (in Chinese) doi: 10.6052/0459-1879-20-415 [10] Yang J, Xie T, Liu XH, et al. Study of unforced unsteadiness in centrifugal pump at partial flow rates. Journal of Thermal Science, 2021, 30: 88-99 doi: 10.1007/s11630-019-1241-2 [11] Wang CM, Xiang L, Tan YH, et al. Experimental investigation of thermal effect on cavitation characteristics in a liquid rocket engine turbopump inducer. Chinese Journal of Aeronautics, 2021, 34(8): 48-57 doi: 10.1016/j.cja.2021.03.035 [12] 黄彪, 樊亚丁, 梁文栋, 吴钦, 王国玉. 诱导轮液氧空化热力学效应数值计算研究. 北京理工大学学报, 2021, 41(01): 53-58Huang Biao, Fan Yading, Liang Wengdong, WU Qin, Wang Guoyu. Numerical Study on Thermodynamic Effect of the Inducer Cavitation in Liquid Oxygen. Transactions of Beijing Institute of Technology, 2021, 41(01): 53-58 (in Chinese) [13] Li DY, Ren ZP, Li Y, et al. Thermodynamic effects on the cavitation flow of a liquid oxygen turbopump. Cryogenics, 2021, 116(6): 103302 [14] Liu YY, Li XJ, Ge MH, et al. Numerical investigation of transient liquid nitrogen cavitating flows with special emphasis on force evolution and entropy features. Cryogenics, 2021, 113: 103225 [15] Ito Y, Tsunoda A, Kurishita Y, et al. Experimental visualization of cryogenic backflow vortex cavitation with thermodynamic effects. Journal of Propulsion and Power, 2016, 32(1): 71-82 [16] Liang WD, Chen TR, Wang GY, et al. Investigation of unsteady liquid nitrogen cavitating flows with special emphasis on the vortex structures using mode decomposition methods. International Journal of Heat and Mass Transfer, 2020, 157: 119880 doi: 10.1016/j.ijheatmasstransfer.2020.119880 [17] Chen TR, Mu ZD, Huang B, et al. Dynamic instability analysis of cavitating flow with liquid nitrogen in a converging−diverging nozzle. Applied Thermal Engineering, 2021, 192: 116870 doi: 10.1016/j.applthermaleng.2021.116870 [18] Wei AB, Yu LY, Gao R, et al. Unsteady cloud cavitation mechanisms of liquid nitrogen in convergent−divergent nozzle. Physics of Fluids, 2021, 33: 092116 [19] Zheng ZY, Wang L, Wei TZ, et al. Experimental investigation of temperature effect on hydrodynamic characteristics of natural cavitation in rotational supercavitating evaporator for desalination. Renewable Energy, 2021, 174: 278-292 doi: 10.1016/j.renene.2021.04.038 [20] 陈家成, 陈泰然, 梁文栋, 谭树林, 耿昊. 收缩扩张管内液氮空化流动演化过程试验研究. 力学学报, 2022, 54(5): 1242-1256 doi: 10.6052/0459-1879-21-614Chen Jiacheng, Chen Tairan, Liang Wendong, Tan Shulin, Geng Hao. Experimental study on the evolution of liquid nitrogen cavitating flows through converging-diverging nozzle. Chinese Journal of Theoretical and Applied Mechanics, 2022, 54(5): 1242-1256 (in Chinese) doi: 10.6052/0459-1879-21-614 [21] Hord J. Cavitation in liquid cryogens. II–Hydrofoil, NASA Contractor Report, NASA CR–2156, 1973 [22] Hord J. Cavitation in liquid cryogens. III–Ogives, NASA Contractor Report , NASA CR-2242, 1973 [23] Ohira K, Nakayama T, Nagai T. Cavitation flow instability of subcooled liquid nitrogen in converging-diverging nozzles. Cryogenics, 2012, 52(1): 35-44 doi: 10.1016/j.cryogenics.2011.11.001 [24] Zhu JK, Xie HJ, Feng KS, et al. Unsteady cavitation characteristics of liquid nitrogen flows through venturi tube. International Journal of Heat and Mass Transfer, 2017, 112: 544-552 doi: 10.1016/j.ijheatmasstransfer.2017.04.036 [25] Zhu JK, Wang SH, Zhang XB. Influences of thermal effects on cavitation dynamics in liquid nitrogen through venturi tube. Physics of Fluids, 2020, 32: 012105 [26] Chen TR, Chen H, Liang WD, et al. Experimental investigation of liquid nitrogen cavitating flows in converging-diverging nozzle with special emphasis on thermal transition. International Journal of Heat and Mass Transfer, 2019, 132: 618-630 doi: 10.1016/j.ijheatmasstransfer.2018.11.157 [27] Liang WD, Chen TR, Wang GY, et al. Experimental investigations on transient dynamics of cryogenic cavitating flows under different free-stream conditions. International Journal of Heat and Mass Transfer, 2021, 178: 121537 doi: 10.1016/j.ijheatmasstransfer.2021.121537 [28] Lord Rayleigh OM. On the pressure developed in a liquid during the collapse of a spherical cavity. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, 1917, 34(200): 94-98 doi: 10.1080/14786440808635681 [29] Yuan H, Prosperetti A. Gas-liquid heat transfer in a bubble collapsing near a wall. Physics of Fluids, 1997, 9(1): 127-142 doi: 10.1063/1.869153 [30] Blake JR, Taib BB, Doherty G, Transient cavities near boundaries. Part 1. Rigid boundary. Journal of Fluid Mechanics, 1986, 170: 479-497 [31] Blake JR, Taib BB, Doherty G. Transient cavities near boundaries part 2. Free surface. Journal of Fluid Mechanics, 1987, 181: 197-212 [32] Lee M, Klaseboer E, Khoo BC. On the boundary integral method for the rebounding bubble. Journal of Fluid Mechanics, 2007, 570: 407-429 doi: 10.1017/S0022112006003296 [33] Zhang AM, Li S, Cui J. Study on splitting of a toroidal bubble near a rigid boundary. Physics of Fluids, 2015, 27(6): 809-822 [34] Supponen O, Obreschkow D, Kobel P, et al. Shock waves from nonspherical cavitation bubbles. Physical Review Fluids, 2017, 2(9): 093601 [35] Obreschkow D, Tinguely M, Dorsaz N, et al. Universal scaling law for jets of collapsing bubbles. Physical Review Letters, 2011, 107(20): 204501 doi: 10.1103/PhysRevLett.107.204501 [36] Zhang AM, Cui P, Cui J, et al. Experimental study on bubble dynamics subject to buoyancy. Journal of Fluid Mechanics, 2015, 776: 137-160 doi: 10.1017/jfm.2015.323 [37] Phan TH, Kadivar E. Thermodynamic effects on single cavitation bubble dynamics under various ambient temperature conditions, Physics of Fluids, 2022, 34: 023318 [38] Florschuetz LW, Chao BT. On the mechanics of vapor bubble collapse. Journal of Heat Transfer, 1965, 87(2): 209 [39] Barbaglia MO, Bonetto FJ. Dependence on liquid temperature and purity of light emission characteristics in single cavitation bubble luminescence. Journal of Applied Physics, 2004, 95: 1756-1759 [40] Takada N, Nakano T, Sasaki K. Formation of cavitation-induced pits on target surface in liquid-phase laser ablation. Applied Physics A-Materials Science & Processing, 2010, 101: 255-258 [41] Dular M, Coutier-Delgosha O. Thermodynamic effects during growth and collapse of a single cavitation bubble. Journal of Fluid Mechanics, 2013, 736: 44-66 doi: 10.1017/jfm.2013.525 [42] Tomita Y, Tsubota M, Nagane K, et al. Behavior of laser-induced cavitation bubbles in liquid nitrogen. Journal of Applied Physics, 2000, 88(10): 5993-6001 doi: 10.1063/1.1320028 [43] Ma XJ, Huang B, Zhao X, et al. Comparisons of spark-charge bubble dynamics near the elastic and rigid boundaries. Ultrasonics Sonochemistry, 2018, 43: 80-90 [44] Turangan CK, Ong GP, Klaseboer E, et al. Experimental and numerical study of transient bubble-elastic membrane interaction. Journal of Applied Physics, 2006, 100(5): 054910 doi: 10.1063/1.2338125 [45] Huang GH, Zhang MD, Han L, et al. Physical investigation of acoustic waves induced by the oscillation and collapse of the single bubble. Ultrasonics Sonochemistry, 2021, 72: 105440 doi: 10.1016/j.ultsonch.2020.105440 [46] Refprop N. Reference fluid thermodynamic and transport properties. NIST Reference Database, Version 9, 2013 [47] 韩磊, 张敏弟, 黄国豪, 黄彪. 自由场空泡溃灭过程能量转化机制研究. 力学学报, 2021, 53(5): 1288-1301 doi: 10.6052/0459-1879-21-006Han Lei, Zhang Mindi, Huang Guohao, Huang Biao. Energy transformation mechanism of a gas bubble collapse in the free-field. Chinese Journal of Theoretical and Applied Mechanics, 2021, 53(5): 1288-1301(in Chinese) doi: 10.6052/0459-1879-21-006 [48] Plesset SM. On the stability of fluid flows with spherical symmetry. Journal of Applied Physics, 1954, 25(1): 96-99 doi: 10.1063/1.1721529 [49] Haas JF, Sturtevant B. Interaction of weak shock waves with cylindrical and spherical gas inhomogeneities. Journal of Fluid Mechanics, 1987, 181: 41-76 doi: 10.1017/S0022112087002003 -