There are big temperature differences at different positions on the first walls facing the plasma in Tokamak device. Free convection experiments of liquid metal on the vertical wall are carried out under the influence of transverse magnetic field. In the experiments, K thermocouple is used to measure the temperatures of the environment and the both sides of the wall, and the flow boundary layer velocity of the wall is measured using a Doppler ultrasonic velocimeter.The experimental results show that the local heat transfer coefficient of the vertical plate is inversely proportional to the characteristic length, while the enhanced heating power increases the surface heat transfer coefficient. Under the condition of the strong magnetic field, the flow and heat transfer effect of the wall boundary layer are generally inhibited. However, in the weak magnetic field, increasing the magnetic field will enhance the effect of free convection and heat transfer on the surface of the plate. Based on the experimental results and existing simulation results, this turning point appears in the N range 1-4.
ZHOU Zhongkai
. Experimental study of free convection of liquid metal on vertical plate under the magnetic field[J]. Journal of University of Chinese Academy of Sciences, 2020
, 37(1)
: 13
-19
.
DOI: 10.7523/j.issn.2095-6134.2020.01.003
[1] Wakashima S, Saitoh T S. Benchmark solutions for natural convection in a cubic cavity using the high-order time-space method[J]. International Journal of Heat and Mass Transfer, 2004, 47(4):853-864.
[2] Tagawa T, Authié G, Moreau R. Buoyant flow in long vertical enclosures in the presence of a strong horizontal magnetic field. Part 1. Fully-established flow[J]. European Journal of Mechanics B Fluids, 2002, 21:383-398.
[3] Authié G, Tagawa T, Moreau R. Buoyant flow in long vertical enclosures in the presence of a strong horizontal magnetic field. Part 2. Finite enclosures[J]. European Journal of Mechanics B Fluids, 2003, 22:203-220.
[4] Wang Z H, Wang S D, Meng X, et al. UDV measurements of single bubble rising in a liquid metal Galinstan with a transverse magnetic field[J]. International Journal Multiphase Flow, 2017, 94:201-208.
[5] Zhang C, Eckert S, Gerbeth G. Experimental study of single bubble motion in a liquid metal column exposed to a DC magnetic field[J]. International Journal Multiphase Flow, 2005, 31:824-842.
[6] Wang Z H, Meng X, Ni M J. Liquid metal buoyancy driven convection heat transfer in a rectangular enclosure in the presence of a transverse magnetic field[J]. International Journal of Heat and Mass Transfer, 2017, 10(113):514-523.
[7] 王增辉, 陈欢, 杨嵩. 磁场作用下三维方腔内液态金属自然对流的数值模拟[J]. 中国科学院大学学报, 2013, 30(4):472-477.
[8] Kays W, Crawford M, Weigand B, et al. 对流传热与传质[M]. 赵镇南,译. 北京:高等教育出版社,2007.
[9] Fujii T, Fujii M. The dependence of local Nusselt number on Prandtl number in the case of free convection along a vertical surface with uniform heat flux[J]. International Journal Heat Mass Transfer, 1976, 19:121-122.
[10] 闻洁, 于兆吉, 吴宏. 竖直平板自由对流强化换热的实验[J]. 航空动力学报, 2008, 23(3):410-414.
[11] Ivan D P, Michele C. MHD free convection in a liquid-metal filled cubic enclosure differential heating[J]. International Journal of Heat and Mass Transfer, 2002, 45(7):1477-1492.
[12] Landau L D, Lifshitz E M, King A L, et al. Electrodynamics of Continuous Media[J]. American Journal of Physics, 1961, 29(9):647-648.
