Experimental and Numerical Investigation of the Thermal Transition Area at the Heated Bottom-Wall of a Horizontal Rectangular Channel

Jaroslav Pulec,Václav Vinš,Jan Novosád,Petra Dančová,R Lenhard,K Kaduchová

doi:10.1051/matecconf/202032802022

Abstract

This article represents a part of an ongoing work on the preparation of an experimental rectangular channel for the PIV and LIF measurements of vortex structures and temperature field in a non-isothermal water flow. The main aim of the current study is to develop a sufficiently accurate simplified numerical model of the real problem. The basic requirements for thermal properties of heated bottom-wall are specified. In the computational model, there are several simplifications such as 2D case and a constant temperature of a heated surface along the longitudinal coordinate. Results of the numerical simulation of the fluid flow and heat transfer are verified on the experimental data obtained in a laboratory channel with the same geometry and similar flow conditions. The presented results helped to define additional requirements on the design of a new experimental channel intended for investigation of the flow instabilities in a non-isothermal liquid flow.

Highlights

The thermal stability and the formation of a secondary water flow in rectangular horizontal channels with heated walls has been investigated experimentally for several decades
Osborne and Incropera [1] carried out a study on an effect of top and bottom wall heating in a horizontal rectangular channel
Incropera et al [2] and Maughan and Incropera [3] published articles dealing with the longitudinal rolls caused by mixed convection in channels with heated bottom

Summary

Introduction

The thermal stability and the formation of a secondary water flow in rectangular horizontal channels with heated walls has been investigated experimentally for several decades. This problem represents a basic case for the investigation of instabilities in a nonisothermal flow. For the accurate investigation of thermal stability, a steep onset of heating on a smooth channel wall is required. Several studies focused on the flow in a channel with the heat wall have been introduced since 1980’s. Osborne and Incropera [1] carried out a study on an effect of top and bottom wall heating in a horizontal rectangular channel.

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Conclusion