ThreeDimensional Numerical Study of Natural Convection of Supercritical Binary Fluid

Abstract

Abstract:

Abstract： This paper numerically investigated the natural convection of supercritical nitrogen/argon (n(N2)∶n(Ar)=0.9∶0.1, n is amount of substance) binary fluid in a 3dimensional rectangular cavity. The results showed that a stable thermal boundary layer forms at the bottom of the cavity during the initial heating phase, and the Piston effect plays a dominant role to accelerate the energy transport in this period. After the thermal plume breaks the boundary layer and moves upward, the natural convection occurs with the appearance of a cold boundary layer near the top. The Soret effect caused by the temperature gradient drives the component migration, and results in the Dufour effect which promotes the energy transport. This results indicate that the Soret effect and Dufour effect can promote the heat and mass transfer in the natural convection of supercritical binary fluids.

Key words: supercritical binary fluid, natural convection, piston effect, Soret effect, Dufour effect, threedimensional numerical simulation

CLC Number:

TK 124

LI Tian1,ZHANG Peng1,LONG Zhiqiang1,SHEN Biao1,2. ThreeDimensional Numerical Study of Natural Convection of Supercritical Binary Fluid[J]. Journal of Shanghai Jiaotong University, 2017, 51(1): 12-.

References

［1］陆辉，沈朝，张乐福. 超临界水中310ODS钢表面氧化膜形成机制和性能［J］. 上海交通大学学报, 2016, 50(4): 528533.
LU Hui, SHEN Zhao, ZHANG Lefu. Formation mechanism and properties of oxide film on 310ODS steel in supercritical water.［J］. Journal of Shanghai Jiao Tong University, 2016, 50(4): 528533.
［2］SHEN B, ZHANG P. RayleighBénard convection in a supercritical fluid along its critical isochore in a shallow cavity［J］. International Journal of Heat and Mass Transfer, 2012, 55(23): 71517165.
［3］SHEN B, ZHANG P. Threedimensional thermoconvection from a nonuniformly heated plate near the liquidvapor critical point［J］. International Journal of Thermal Sciences, 2015, 89: 136153.
［4］HASAN N, FAROUK B. Buoyancy driven convection in nearcritical and supercritical fluids［J］. International Journal of Heat and Mass Transfer, 2012, 55(15): 42074216.
［5］HASAN N, FAROUK B. Thermoacoustic transport in supercritical fluids at nearcritical and nearpseudocritical states［J］. The Journal of Supercritical Fluids, 2012, 68: 1324.
［6］RAHMAN M A, SAGHIR M Z. Thermodiffusion or Soret effect: Historical review［J］. International Journal of Heat and Mass Transfer, 2014, 73: 693705.
［7］HAYAT T, SHEHZAD S A, ALSAEDI A. Soret and Dufour effects on magnetohydrodynamic (MHD) flow of Casson fluid［J］. Applied Mathematics and Mechanics, 2012, 33(10): 13011312.
［8］MOHAMMED H A, ALASWADI A A, SHUAIB N H, et al. Convective heat transfer and fluid flow study over a step using nanofluids: A review［J］. Renewable and Sustainable Energy Reviews, 2011, 15(6): 29212939.
［9］NAKANO A. Studies on piston and soret effects in a binary mixture supercritical fluid［J］. International Journal of Heat and Mass Transfer, 2007, 50(23): 46784687.
［10］LONG Z Q, ZHANG P, SHEN B, et al. Experimental investigation of natural convection in a supercritical binary fluid［J］. International Journal of Heat and Mass Transfer, 2015, 90: 922930.
［11］龙志强. 超临界二元混合流体热质传递机理及应用研究［D］. 上海：上海交通大学机械与动力工程学院, 2014.
［12］陶文铨. 数值传热学［M］. 2版. 西安: 西安交通大学出版社. 2001: 280320.

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