Library Subscription: Guest
Proceedings of CHT-12. ICHMT International Symposium on Advances in Computational Heat Transfer.
July, 1-6, 2012, Bath, England

DOI: 10.1615/ICHMT.2012.CHT-12


ISBN: 978-1-56700-303-1

ISSN: 2578-5486

NUMERICAL INVESTIGATION FOR NATURAL CONVECTION IN A VERTICAL OPEN-ENDED CHANNEL: COMPARISON WITH EXPERIMENTAL DATA

pages 1527-1548
DOI: 10.1615/ICHMT.2012.CHT-12.920
Get accessGet access

ABSTRACT

The present study deals with natural convection flow in a vertical open-ended channel with wall constant heat flux. The experimental and numerical investigations are both conducted using water as the working fluid in order to get rid of radiation heat transfer and to have a pure convective flow. The numerical code is developed using Finite Differences scheme of second order in time and space to solve the elliptic two-dimensional Navier-Stokes equations under the Boussinesq assumption. Concerning the experimental apparatus, it consists of two heated walls immersed in water. Temperature and velocity measurements are provided (by thermocouple and Laser Doppler Velocimetry system) for different modified Rayleigh numbers based on the walls spacing b : Ra*b = 1.67×106,3.6×106,8.97×106,1.69×107,4.29×107. The numerical code is first validated with a numerical benchmark for the case of natural convection in air between asymmetrically heated walls under uniform heat flux without considering radiative effects. Then, the numerical simulations are performed for the case of natural convection of water between two symmetrically heated walls by uniform heat flux and compared to experimental data. The code provides a satisfactory prediction of main quantities compared to the experimental results but only for the lowest Rayleigh numbers Ra*b = 1.67×106,3.6×106. For higher modified Rayleigh numbers Ra*b = 8.97×107,1.69×107,4.29×107, the flow becomes three-dimensional and turbulent. Therefore, 2D numerical simulations fail to predict flow and heat transfer for this range of modified Rayleigh number.

Begell Digital Portal Begell Digital Library eBooks Journals References & Proceedings Research Collections Prices and Subscription Policies Begell House Contact Us Language English 中文 Русский Português German French Spain