Numerical Simulation On Flow And Heat Transfer In An Alternating Elliptical Axis Tube.pdf

Numerical Simulation On Flow And Heat Transfer
In An Alternating Elliptical Axis Tube

Bin LI, Bo FENG, Wen-Quan TAO and Ya-Ling HE

State Key Laboratory of Multiphase Flow in Power Engineering
School of Energy & Power Engineering
Xi’an Jiaotong University, Xi’an, 710049, China
EMAIL: leewenwu@


1. Introduction

Heat exchangers are widely used in many engineering fields, and circular tubes are the monly adopted heat
transfer element. In order to enhance heat transfer different kinds of fins are often adopted either at the outside surface
or within the tube. As far as the tube itself is concerned, elliptical tube has been found in favor of reduction the flow
resistance for the external cross fluid flow. Very limited studies have been performed on how to enhance the heat
transfer of internal fluid flow in an elliptical tube without the usage of fins.
Although the heat transfer enhancement have been studied for more than half a century, the basic mechanism of
enhancing convective heat transfer was not clearly revealed up to the end of last century[1]. In 1998 Guo[2] and his co-
workers proposed a novel concept of enhancing convective heat transfer of parabolic flow: reduction the intersection
angle between the velocity and the temperature gradient is the basic mechanism of convective heat transfer
enhancement. Later this idea was