Numerical Simulation on flow characteristics of the supercritical fluid in Micro-Fin Tube

¹ Institute of solar engineering technology, Northwest Engineering Corporation Limited, Power China, 710065, Xi’an China;
² Power China Research Center of Solar Thermal Power Engineering Technology, 710065, Xi’an China

^* Corresponding author: chen_kang@xjtu.edu.cn

Abstract

The flow characteristics of the supercritical fluid in the micro-fin tube is the theoretical basis for the development of heat transfer enhancement and flow resistance reduction in the micro-fin tube. For micro-fin tubes with different fin shapes, this paper considered the physical properties of nitrogen in the supercritical state and adopted the enhanced wall function, reasonable turbulence equations, and control equations, etc., to numerically simulate the flow of nitrogen in a 2 mm micro-fin tube under supercritical pressure. The distribution of velocity field, turbulence and pressure field of supercritical nitrogen in the micro-fin tube was analyzed. The turbulent flow mechanism of the micro-fins was obtained, and it is found that the existence of the viscous bottom layer slows down the inter-costal fluid velocity and increases the frictional resistance during the flow process.