Effect of Insulated Oblique Plates on Heat Transfer and Recirculating Flow in a Channel

Yinxiao Zhan,Tae Seon Park

doi:10.4236/jamp.2014.26048

Abstract

Flow and heat transfer characteristics of a channel with oblique plates which are mounted periodically on the channel wall have been numerically investigated in a laminar range. The main objective of the present study is to find the effect of the tilt angle of oblique plate on pressure drop and heat transfer characteristics in unsteady states. To get the different conditions of the heat transfer and flow evolution, two key parameters of the Reynolds number and the tilt angle of oblique plate are considered. At Re=200,600 , the tilt angles are changed for the range of 50° - 130°. The computational results show that the heat transfer and pressure drop are strongly dependent on the tile angle and Reynolds number. When the flows are unsteady, the tilt angle has an important role in the heat transfer enhancement. Oscillatory structures induce the better mixing of the thermal field and promote the wall heat transfer. For a constant plate length, the wall heat trans- fer is maximized near the 90° - 100°. This is strongly coupled with the variations of flow mixing induced by the oblique plate.

Highlights

When the flow in a channel is destabilized by periodic disturbance promoters, the heat transfer is significantly changed [1]
It can be seen that vortices induced by oblique plate along the walls remove to the downstream
Fluid flow and heat transfer characteristics of channel flow with oblique plate have been numerically investigated by the finite volume method

Summary

Introduction

When the flow in a channel is destabilized by periodic disturbance promoters, the heat transfer is significantly changed [1]. Valencia [2] [3] investigated flow structure and heat transfer in a channel with periodically mounted transverse vortex generators in the Reynolds number range of steady to oscillatory flow. They found self-sustained oscillations enhanced mixing between the core fluid and the fluid near the wall. Saha and Acharya [4] analyzed the unsteady three-dimensional flow and heat transfer in a pin-fin heat exchanger. They showed the heat transfer is enhanced significantly when the flow becomes unsteady. Guzman and Valle [5] investigated a transition scenario of two Hopf bifurca-

Objectives

Methods

Results

Conclusion