多超声振子作用下气泡动力学数值模拟

doi:10.11949/0438-1157.20201498

摘要/Abstract

摘要：

超声对强化吸收制冷循环中发生器内溴化锂水溶液沸腾传热有重要意义，目前开展的相关研究较少，尤其多超声振子气泡动力学方面的理论尚未报道。为探究振子数量对溶液空化特性的影响，构建多振子气泡动力学模型，以纯水为例验证了模型准确性，探讨了不同影响因素对溶液空化特性的影响。模拟结果表明：总声强为1 W/cm²，振子数量由1增加至5时，空化气泡最大半径增加了44.12%，振子数量达到24～25个时，气泡最大半径增加率仅为1%；发生压力对空化效应的影响随着振子数量的增多而增大，单振子在吸收制冷系统的真空发生器更易产生稳态空化，而多振子更易在真空发生器内产生瞬态空化；多振子频率均匀度越小，空化强度越大，声强均匀度对空化强度的影响可忽略。

关键词: 超声空化, 溴化锂水溶液, 数值模拟, 多频超声, 气泡动力学

Abstract:

Ultrasound plays an important significance in enhancing the boiling heat-transfer of lithium bromide aqueous solution in the generator of absorption refrigeration system, there are few theoretical and experimental studies about the application of ultrasound heat-transfer enhancement technology in the boiling heat-transfer of lithium bromide aqueous solution in the generator, especially in the field of solution bubble dynamics with multi-ultrasonic vibrators at present. In order to investigate the influence of the quantities of ultrasonic vibrators on the characteristics of solution cavitation bubble dynamics, a mathematical model of lithium bromide aqueous solution bubble dynamics is constructed, in addition, the accuracy of the mathematical model is verified with the degassed water, and the effect of different influencing factors on the characteristics of solution cavitation bubble dynamics are discussed. The results indicate that, when the total sound intensity of 1 W/cm², as the quantities of ultrasonic vibrators rise from 1 to 5, the maximum radius of a cavitation bubble is increased by 44.12%, while the maximum radius of cavitation bubble is increased by no more than 1% at the quantities of ultrasonic vibrators of 24—25; The effect of the generating pressure (ambient pressure) on the solution cavitation effect would be increased with the quantities of ultrasonic vibrators increase, in the absorption refrigeration system, the lithium bromide aqueous solution in vacuum generator is more likely to produce steady cavitation process with the single-ultrasonic vibrator, nevertheless, the solution in vacuum generator is more likely to produce transient cavitation process with the multi-ultrasonic vibrators; when the ultrasonic frequency uniformities of ultrasonic vibrators decrease, the intensity of solution cavitation effect would be increased, while the ultrasonic intensity uniformities of ultrasonic vibrators on the intensity of solution cavitation effect could be neglected.

Key words: ultrasonic cavitation, lithium bromide aqueous solution, numerical simulation, multi-frequency ultrasound, bubble dynamics

中图分类号:

TQ 025.2

候召宁, 王林, 闫晓娜, 李修真, 王占伟, 梁坤峰. 多超声振子作用下气泡动力学数值模拟[J]. 化工学报, 2021, 72(S1): 362-370.

HOU Zhaoning, WANG Lin, YAN Xiaona, LI Xiuzhen, WANG Zhanwei, LIANG Kunfeng. Numerical simulation of bubble dynamics under multi-ultrasonic vibrators[J]. CIESC Journal, 2021, 72(S1): 362-370.

图/表 13

图1 空化泡核受力模型

Fig.1 Mechanical model of cavitation bubble

图2 均匀介质流体中球形气泡

Fig.2 Spherical bubbles in homogeneous media

图3 气泡动力学模型准确性对比

Fig.3 Comparison of accuracy of bubble dynamics model

图4 发生压力对液体空化气泡运动的影响

Fig.4 Effect of generating pressure on cavitation bubble dynamics

图5 振子数量对溶液空化特性的影响

Fig.5 Effect of quantities of ultrasonic vibrators on solution bubble dynamics

图6 振子声强均匀度对溶液空化特性的影响

Fig.6 Effect of ultrasonic intensity uniformities of ultrasonic vibrators on solution bubble dynamics

图7 振子声波相位差对溶液空化特性的影响

Fig.7 Effect of ultrasonic vibrators phase difference on solution bubble dynamics

图8 振子频率均匀度对溶液空化特性的影响

Fig.8 Effect of ultrasonic frequency uniformities of ultrasonic vibrators on solution bubble dynamics

图9 溶液浓度对空化特性的影响

Fig.9 Effect of solution concentration on cavitation bubble dynamics

图10 溶液温度对溶液空化特性的影响

Fig.10 Effect of solution temperature on cavitation bubble dynamics

图11 发生压力对溶液空化特性的影响

Fig.11 Effect of generating pressure on cavitation bubble dynamics

图12 超声频率对溶液空化特性的影响

Fig.12 Effect of ultrasonic frequency on cavitation bubble dynamics

图13 总声强对溶液空化特性的影响

Fig.13 Effect of ultrasonic intensity on cavitation bubble dynamics

参考文献 30

1	Ibrahim N I, Al-Sulaiman F A, Ani F N. Solar absorption systems with integrated absorption energy storage - a review [J]. Renewable and Sustainable Energy Reviews, 2018, 82: 1602-1610.
2	Legay M, Gondrexon N, Le Person S, et al. Enhancement of heat transfer by ultrasound: review and recent advances [J]. International Journal of Chemical Engineering, 2011, 2011: 1-17.
3	Delouei A A, Sajjadi H, Izadi M, et al. The simultaneous effects of nanoparticles and ultrasonic vibration on inlet turbulent flow: an experimental study [J]. Applied Thermal Engineering, 2019, 146: 268-277.
4	Chang T B, Wang Z L. Experimental investigation into effects of ultrasonic vibration on pool boiling heat transfer performance of horizontal low-finned U-tube in TiO₂/R141b nanofluid [J]. Heat and Mass Transfer, 2016, 52(11): 2381-2390.
5	Chen R H, Chang T B. Heat transfer enhancement of pool boiling for a horizontal U-tube using TiO₂-R141b nanofluid [J]. Journal of Mechanical Science and Technology, 2014, 28(12): 5197-5204.
6	Shen G Q, Ma L K, Zhang S X, et al. Effect of ultrasonic waves on heat transfer in Al₂O₃ nanofluid under natural convection and pool boiling [J]. International Journal of Heat and Mass Transfer, 2019, 138: 516-523.
7	Setareh M, Saffar-Avval M, Abdullah A. Experimental and numerical study on heat transfer enhancement using ultrasonic vibration in a double-pipe heat exchanger [J]. Applied Thermal Engineering, 2019, 159: 113867.
8	Zheng M J, Li B, Wan Z P, et al. Ultrasonic heat transfer enhancement on different structural tubes in LiBr solution [J]. Applied Thermal Engineering, 2016, 106: 625-633.
9	Song J T, Tian W, Xu X F, et al. Thermal performance of a novel ultrasonic evaporator based on machine learning algorithms [J]. Applied Thermal Engineering, 2019, 148: 438-446.
10	Tang J G, Sun L C, Wu D, et al. Effects of ultrasonic waves on subcooled pool boiling on a small plain heating surface [J]. Chemical Engineering Science, 2019, 201: 274-287.
11	Bonekamp S, Bier K. Influence of ultrasound on pool boiling heat transfer to mixtures of the refrigerants R23 and R134A [J]. International Journal of Refrigeration, 1997, 20(8): 606-615.
12	张东伟, 李凯华, 周俊杰, 等. 超声波强化传热的链式反应机理与模拟研究 [J]. 工程热物理学报, 2017, 38(1): 145-148.
	Zhang D W, Li K H, Zhou J J, et al. Investigation on the chain reaction mechanism and simulation of heat transfer process enhanced by ultrasonic vibrations [J]. Journal of Engineering Thermophysics, 2017, 38(1): 145-148.
13	Kim H Y, Kim Y G, Kang B H. Enhancement of natural convection and pool boiling heat transfer via ultrasonic vibration [J]. International Journal of Heat and Mass Transfer, 2004, 47(12/13): 2831-2840.
14	Yasui K. Effects of thermal conduction on bubble dynamics near the sonoluminescence threshold [J]. The Journal of the Acoustical Society of America, 1995, 98(5): 2772-2782.
15	Liu B, Cai J, Huai X L. Heat transfer with the growth and collapse of cavitation bubble between two parallel heated walls [J]. International Journal of Heat and Mass Transfer, 2014, 78: 830-838.
16	Kanthale P, Ashokkumar M, Grieser F. Sonoluminescence, sonochemistry (H₂O₂ yield) and bubble dynamics: frequency and power effects [J]. Ultrasonics Sonochemistry, 2008, 15(2): 143-150.
17	Kanthale P M, Brotchie A, Ashokkumar M, et al. Experimental and theoretical investigations on sonoluminescence under dual frequency conditions [J]. Ultrasonics Sonochemistry, 2008, 15(4): 629-635.
18	Ye L Z, Zhu X J, Liu Y. Numerical study on dual-frequency ultrasonic enhancing cavitation effect based on bubble dynamic evolution [J]. Ultrasonics Sonochemistry, 2019, 59: 104744.
19	Suo D J, Govind B, Zhang S Q, et al. Numerical investigation of the inertial cavitation threshold under multi-frequency ultrasound [J]. Ultrasonics Sonochemistry, 2018, 41: 419-426.
20	Wu H, Zhou C, Pu Z H, et al. Effect of low-frequency ultrasonic field at different power on the dynamics of a single bubble near a rigid wall [J]. Ultrasonics Sonochemistry, 2019, 58: 104704.
21	Moholkar V S. Mechanistic optimization of a dual frequency sonochemical reactor [J]. Chemical Engineering Science, 2009, 64(24): 5255-5267.
22	Zhang Y N, Zhang Y N, Li S C. The secondary Bjerknes force between two gas bubbles under dual-frequency acoustic excitation [J]. Ultrasonics Sonochemistry, 2016, 29: 129-145.
23	Ebrahiminia A, Mokhtari-Dizaji M, Toliyat T. Dual frequency cavitation event sensor with iodide dosimeter [J]. Ultrasonics Sonochemistry, 2016, 28: 276-282.
24	Yang X M, Church C C. A model for the dynamics of gas bubbles in soft tissue [J]. The Journal of the Acoustical Society of America, 2005, 118(6): 3595-3606.
25	Rayleigh O M F R S. Ⅷ. On the pressure developed in a liquid during the collapse of a spherical cavity [J]. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, 1917, 34(200): 94-98.
26	Gogate P R, Tatake P A, Kanthale P M, et al. Mapping of sonochemical reactors: review, analysis, and experimental verification [J]. AIChE Journal, 2002, 48(7): 1542-1560.
27	Kaita Y. Thermodynamic properties of lithium bromide-water solutions at high temperatures [J]. International Journal of Refrigeration, 2001, 24(5): 374-390.
28	Malhotra A, Panda D M R. Thermodynamic properties of superheated and supercritical steam [J]. Applied Energy, 2001, 68(4): 387-393.
29	Suo D J, Guo S J, Lin W L, et al. Thrombolysis using multi-frequency high intensity focused ultrasound at MHz range: an in vitro study [J]. Physics in Medicine and Biology, 2015, 60(18): 7403-7418.
30	李争彩, 林书玉. 超声空化影响因素的数值模拟研究[J]. 陕西师范大学学报(自然科学版), 2008, 36(1): 38-42.
	Li Z C, Lin S Y. Numerical simulation of the factors influencing ultrasonic cavitation [J]. Journal of Shaanxi Normal University (Natural Science Edition), 2008, 36(1): 38-42.

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