双股等离子体射流在液体工质中的扩展特性研究

Simulation of Expansion Characteristics of Twin Plasma Jets in Liquid

摘要

为深入探究电热化学发射背景下双股等离子体射流在液体工质中的扩展特性,建立了等离子体射流在液体工质中扩展的三维非稳态模型,对双股等离子体射流在液体工质中的扩展过程进行了数值模拟,获得了流场两相分布、压力、温度以及速度的时空分布。结果表明:双股等离子射流在液体工质中先在底部沿径向扩展,而后迅速在轴向扩展。由于Taylor-Helmholtz不稳定性,射流头部呈尖锥形,轮廓破碎褶皱,由于双股间射流相互干扰,内侧轮廓波动比外侧更为剧烈,近喷嘴处射流外侧由于液体工质回流挤压出现颈缩现象。射流内侧速度高于外侧,速度场高速区呈现向中心汇聚的趋势。压力场、温度场受膨胀波和压缩波交替作用影响,存在高低值相间的结构,射流扩展后期流场中部外侧形成大涡旋,涡旋处会明显消耗等离子体射流的能量,压力、温度衰减显著。

Abstract

In order to investigate the expansion characteristics of twin plasma jets in liquid under the background of electrothermal chemical emission, a three-dimensional unsteady model of the interaction between plasma jets and liquid was developed, and numerical simulations were conducted to analyze the expansion characteristics of twin plasma jets in liquid. The distributions of the two-phase and the streamlines in the flow field, distributions of pressure, temperature, and velocity were acquired. Results show that twin plasma jets firstly expand in the radial direction at the bottom in the chamber, and then expand rapidly in the axial direction. Due to the Taylor-Helmholtz instability, the head of the jet is pointedly conical, and the profile is broken and folded. The inner profile fluctuation is more intense than the outer one due to the mutual interference of the jets between the two phases. The necking phenomenon occurs at the outer side of the jet near the nozzle due to the squeeze of the return flow of the liquid. The velocity of the inner side is higher than that of the outer, therefore, the high-speed area of the velocity field shows a tendency to converge to the center. The pressure and temperature are affected by the alternation of expansion wave and compression wave, and there is a structure of high and low values fluctuation. In the late stage of twin plasma jets expansion, large vortexes are formed in the middle outer side of the flow field which will obviously consume the energy of the plasma jets, and the pressure and temperature decrease significantly.

关键词

等离子射流 / 液体工质 / Kelvin-Helmoltz不稳定性 / Taylor空腔 / 数值模拟

Key words

plasma jet / liquid mass / Kelvin-Helmoltz instability / Taylor cavity / numerical simulation

参考文献

[1] 李鸿志. 电热化学发射技术的研究进展[J]. 南京理工大学学报, 2003, 27(5): 449-465.

[2] LI Hongzhi. Research progress of electrothermal chemical emission technology[J]. Journal of Nanjing University of Science and Technology, 2003, 27(5): 449-465. (in Chinese)

[3] KIM K, IM S, CHOE M, et al. Relationship between flame thickness and velocity based on thermodynamic three kernels in a constant volume combustion chamber[J]. Journal of Mechanical Science and Technology, 2019, 33(5): 2459-2470.

[4] GAO H, MATTHEWS R D, HALL M J, et al. From spark plugs to railplugs-the characteristics of a new ignition system[J]. SAE Transactions, 2004, 1: 1546-1556.

[5] 宋振兴, 何立明, 张建邦, 等. 超音速等离子体点火过程的三维数值模拟[J]. 强激光与粒子束, 2012, 24(11): 2746-2750.

[6] SONG Zhenxing, HE Liming, ZHANG Jianbang, et al. 3D numerical simulation of supersonic plasma ignition process[J]. High Power Laser and Particle Beams, 2012, 24(11): 2746-2750. (in Chinese)

[7] PASTOR J V, GARCIA-OLIVER J M, GARCIA A, et al. Effect of laser induced plasma ignition timing and location on diesel spray combustion[J]. Energy Conversion & Management, 2017, 133: 41-55.

[8] 周彦煌, 刘东尧, 余永刚. 非稳态等离子体射流在液体中的膨胀特性[J]. 南京理工大学学报(自然科学版), 2003, 27(5): 525-529.

[9] ZHOU Yanhuang, LIU Dongyao, YU Yonggang. Expansion characteristics of unstable plasma jet in liquid[J]. Journal of Nanjing University of Science and Technology(Nature Science), 2003, 27(5): 525-529. (in Chinese)

[10] XUE X, YU Y, MANG S. Physical characteristics on high-pressure combustion and propelling process of bulk-loaded energetic liquid[J]. Applied Thermal Engineering, 2016, 98: 1070-1079.

[11] 刘东尧, 周彦煌. 液体发射药电热化学发射内弹道一维两相流模型及数值模拟[J]. 爆炸与冲击, 2002, 22(2): 158-162.

[12] LIU Dongyao, ZHOU Yanhuang. One-dimensional two-phase flow model and numerical simulation of liquid propellant electrothermal chemical launch interior ballistics[J]. Explosion and Shock Waves, 2002, 22(2): 158-162. (in Chinese)

[13] YU Y, YAN S, ZHAO N, et al. Influence of boundary shape on interaction process of plasma jet and liquid media[J]. International Journal of Applied Electromagnetics and Mechanics, 2010, 33(1): 541-548.

[14] YU Y, ZHANG Q, ZHAO N, et al. Experimental study and numerical simulation on propagation properties of a plasma jet in a cylindrical liquid chamber[J]. Journal of Applied Mechanics, 2013, 80(3): 031406.

[15] 张琦, 余永刚, 刘东尧, 等. 等离子射流在圆柱充液室中扩展、掺混的实验及数值模拟[J]. 推进技术, 2011, 32(6): 869-877.

[16] ZHANG Qi, YU Yonggang, LIU Dongyao, et al. Experiment and numerical simulation for propagating and mixing process of the plasma jet in liquid medium[J]. Journal of Propulsion Technology, 2011, 32(6): 869-877. (in Chinese)

[17] MANG S, YU Y, ZHANG Q. Numerical models for interactions of ablating-capillary plasma with air and bulk-loaded liquid[J]. IEEE Transactions on Plasma Science, 2018, 46(8): 3065-3074.

[18] 刘怡, 余永刚, 莽珊珊. 脉冲等离子射流在液体介质中扩展特性的测量与分析[J]. 含能材料, 2017, 25(2): 144-149.

[19] LIU Yi, YU Yonggang, MANG Shanshan. Measurement and analysis of expansion characteristics of pulsed plasma jet in liquid medium[J]. Chinese Journal of Energetic Materials, 2017, 25(2): 144-149. (in Chinese)

[20] LIU Y, YU Y, MANG S. Expansion characteristics of a plasma jet in the stepped-wall liquid chamber[J]. AIP Advances, 2018, 8(12): 125305.

[21] LIU Y, LIN L, YU Y, et al. Plasma-liquid interface manipulated by chamber structure: an experimental and theoretical approach[J]. ACS Applied Materials and Interfaces, 2020, 12(39): 44238-44247.

[22] 薛皓琦, 余永刚. 喷嘴直径对等离子射流扩展特性的影响[J]. 弹道学报, 2023, 35(4): 27-34.

[23] XUE Haoqi, YU Yonggang. Influence of nozzle diameter on plasma jet expansion characteristics[J]. Journal of Ballistics, 2023, 35(4): 27-34. (in Chinese)

[24] 薛皓琦, 余永刚. 等离子射流在模拟液体发射药中扩展特性的数值模拟[J]. 含能材料, 2024, 32(5): 510-517.

[25] XUE Haoqi, YU Yonggang. Simulation of spreading characteristics of plasma jet in simulative liquid propellant[J]. Chinese Journal of Energetic Materials, 2024, 32(5): 510-517. (in Chinese)

[26] 赵嘉俊, 余永刚. 侧喷孔分布对多股燃气射流在充液室中扩展特性的影响[J]. 工程力学, 2017, 34(7): 241-248.

[27] ZHAO Jiajun, YU Yonggang. Effects of the distribution of lateral orifices on expansion of multiple combustion gas jets in water-filled chamber[J]. Engineering Mechanics, 2017, 34(7): 241-248. (in Chinese)

[28] 胡志涛, 余永刚, 曹永杰. 多股贴壁燃气射流在圆柱型充液室中的扩展特性[J]. 含能材料, 2016, 24(2): 177-181.

[29] HU Zhitao, YU Yonggang, CAO Yongjie. Experimental study on expansion characteristics of multiple wall combustion-gas jets in cylindrical filling liquid chamber[J]. Chinese Journal of Energetic Materials, 2016, 24(2): 177-181. (in Chinese)

[30] 冯博声, 薛晓春. 四股燃气射流在整装式液体中扩展特性的实验研究[J]. 含能材料, 2017, 25(12): 1004-1010.

[31] FENG Bosheng, XUE Xiaochun. Experimental study on expansion characteristics of four combustion-gas jet in bulk-loaded liquid[J]. Chinese Journal of Energetic Materials, 2017, 25(12): 1004-1010. (in Chinese)

[32] ZHOU L, YU Y. Study on interaction characteristics between multi gas jets and water during the underwater launching process[J]. Experimental Thermal and Fluid Science: International Journal of Experimental Heat Transfer, Thermodynamics, and Fluid Mechanics, 2017, 83: 200-206.

[33] 刘怡, 余永刚, 莽珊珊. 喷射压力对等离子体射流在液体中扩展的影响[J]. 兵工学报, 2018, 39(12): 2354-2362.

[34] LIU Yi, YU Yonggang, MANG Shanshan. Effect of injection pressure on propagation of plasma jet in liquid[J]. Acta Armamentarii, 2018, 39(12): 2354-2362. (in Chinese)

[35] ZHOU X, LI Y, WANG J, et al. The temperature measurement of the electrothermal-chemical launcher plasma by atomic emission spectroscopy[J]. IEEE Transactions on Plasma Science, 2001, 29(2): 360-364.