Numerical Study on Supercritical Fluids Flow and Heat Transfer under Buoyancy
Heat transfer at supercritical pressure is mainly characterized by the thermal physical properties which vary strongly near the vicinity of pseudo-critical temperature. The strong variation of density leads to a great buoyancy effect, which imposes great influence on supercritical fluid flow and heat transfer. In this paper, the supercritical fluids heat transfer at buoyancy aided flow is numerical studied. Traditional turbulence models use SGDH and GGDH as buoyancy term, which underestimates buoyancy effect. In this paper, an improved k-ε-kt-εt is proposed, and a modified AFM is used as buoyancy model. The calculation of supercritical fluids heat transfer shows that traditional turbulence model overestimate wall temperature, and the present model can compute wall temperature correctly. The numerical result shows the buoyancy modifies shear stress and flow velocity distribution which leads to heat transfer impairment and recovery. Moreover, buoyancy effect is an important source of turbulent kinetic energy, which enhances heat transfer ability.
Turbulence k-ε Model Algebraic Flux Model Buoyancy Supercritical Pressure
Zhang Hao Xie Zheng-Rui Yang Yan-Hua
School of Nuclear Science and Engineering, Shanghai Jiao Tong University 800 Dongchuan Road, Min Hang, Shanghai, China
国际会议
上海
英文
1248-1259
2010-10-10（万方平台首次上网日期，不代表论文的发表时间）