Abstract:Volume of fluid (VOF) model and userdefined function were applied to simulate the flow boiling of water in microchannel with Vshaped, trapezoidal, square and dovetail-shaped cavities on the heating wall. The effects of cavity shape on the bubble behaviors of bubble nucleation, growth, detachment and coalescence were analyzed. The results show that when the heat flux on the wall is 300 kW· m-2, all cavities are activated as boiling nucleation sites. Compared with the other cavities with V, trapezoidal and square shapes, the onset of boiling time in microchannel with dovetailed cavities is relatively earlier when flow boiling occurs. In the nucleate boiling stage, compared with the trapezoidal cavity, the growth and detachment times of the bubble in the microchannel with dovetailed cavity are decreased by 7.50 ms and 6.70 ms, respectively, while the detachment frequency of the bubble is increased from 33.8 s-1 to 66.7 s-1, which is helpful to enhance the flow boiling heat transfer of water in microchannel. The coalescence and elongation of the detached bubbles in microchannel can increase the evaporation area of liquid film near the heating wall and improve the disturbance of the liquid phase simultaneously. However, it can cause local drying on the heating wall and reduce the stability and reliability of flow boiling heat transfer in microchannel.
王迎慧, 刘建停. 内设凹槽微通道内的气泡行为与流动沸腾换热特性#br#[J]. 江苏大学学报(自然科学版), 2022, 43(5): 587-592.
WANG Yinghui, LIU Jianting. Bubble behaviors and flow boiling heat transfer characteristics in microchannel with cavities[J]. Journal of Jiangsu University(Natural Science Eidtion)
, 2022, 43(5): 587-592.
ZENG J, ZHANG S W, TANG Y, et al. Flow boiling characteristics of microgrooved channels with reentrant cavity array at different operational conditions[J]. International Journal of Heat and Mass Transfer, 2017, 114: 1001-1012.
[2]
LEE J Y, KIM M H, KAVIANY M, et al. Bubble nucleation in microchannel flow boiling using single artificial cavity[J]. International Journal of Heat and Mass Transfer, 2011, 54: 5139-5148.
[3]
YIN L F, JIA L. Confined bubble growth and heat transfer characteristics during flow boiling in microchannel[J]. International Journal of Heat and Mass Transfer, 2016, 98: 114-123.
[4]
MAGNINI M, THOME J R. An updated threezone heat transfer model for slug flow boiling in microchannels[J]. International Journal of Multiphase Flow, doi: 10. 1016/j. ijmultiphaseflow. 2017. 01. 015.
[5]
郭雷. 微细通道流动沸腾换热机理及实验研究[D]. 济南: 山东大学, 2011.
[6]
KUO C J,KOSAR A, PELES Y, et al. Bubble dynamics during boiling in enhanced surface microchannels[J]. Journal of Microelectromechanical Systems, 2006, 15(6): 1514-1527.
[7]
KUO C J, PELES Y. Local measurement of flow boiling in structured surface microchannels[J]. International Journal of Heat and Mass Transfer, 2007, 50: 4513-4526.
[8]
LEE W H. A pressure iteration scheme for twophase flow modeling[M]. Computational Methods for Twophase Flow and Particle Transport (With CDROM). London, UK. World Science Publishing Co, 2013:61-82.
[9]
CHENG X, WU H Y. Enhanced flow boiling performance in highaspectratio groovewall microchannels[J]. International Journal of Heat and Mass Transfer, doi:10. 1016/j. ijheatmasstransfer. 2020. 120468.
WANG Y H, ZHANG L. Bubble behavior and flow boiling characteristics in microchannels with Ωgrooves[J]. Journal of Jiangsu University(Natural Science Edition), 2020, 41(4): 405-410. (in Chinese)
[11]
GONG S, CHENG P, QUAN X J. Twodimensional mesoscale simulations of saturated pool boiling from rough surfaces, Part I: Bubble nucleation in a single cavity at low superheats[J]. International Journal of Heat and Mass Transfer, 2016, 100: 927-937.
[12]
KURUL N, PODOWSKI M Z. Multidimensional effects in forced convection subcooled boiling[C]∥9th International Heat Transfer Conference. Jerusalem, Israel:[s.n.], 1990:21-26.
[13]
CHANG Y H, FERNG Y M. Experimental investigation on bubble dynamics and boiling heat transfer for saturated pool boiling and comparison data with previous works[J]. Applied Thermal Engineering, 2019, 154: 284-293.
[14]
KHOSHNEVIS A, SARCHAMI A, ASHGRIZ N. Effect of nucleation bubble departure diameter and frequency on modeling subcooled flow boiling in an annular flow[J]. Applied Thermal Engineering, doi: 10. 1016/j. applthermaleng. 2018. 02. 032.