Library Subscription: Guest
ICHMT DL Home Current Year Archives Executive Committee International Centre for Heat and Mass Transfer

HEAT TRANSFER BETWEEN DEFORMABLE MAGNETIC BEDS AND IMMERSED SURFACES: Cases of gas-fluidized beds

DOI: 10.1615/ICHMT.2004.IntThermSciSemin.280
pages 267-274

Jordan Y. Hristov
Department of Chemical Engineering, University of Chemical Technology and Metallurgy, 1756 Sofia, 8 Kl. Ochridsky str., Bulgaria

Abstract

The paper considers heat transfer between immersed surfaces and deformable magnetic particle beds in special cases of applications magnetically stabilized bed techniques. The first attempt to analyze the data [1-3] yielded uniform presentation of the existing results. The major efforts were stressed to recognize the effect of the fluidization regime on the heat transfer coefficients and to present the data via Nusselt number [1-3] and Chilton-Colburn dimensionless correlations [3].
The aforementioned investigations did not investigate the effect of the changing bed porosity of the stabilized bed on the heat transfer coefficients. The main problem hindering the studies in the past is the absence of information about the links between the deformation characteristics of the porous medium (the deformable magnetic bed) and its hydraulic characteristics. The recent results [4-6] demonstrate the applicability of the Richardson-Zaki (1954) scaling law, U/Ut = εn to the bed expansion. This result relates the superficial fluid velocity, the overall bed porosity and the effect of the magnetic field on the scaling exponents.
The present work focuses on scaling relationships between the bed porosity and the internal length scale of the granular bed (the permeability K of the Forchheimer equation). The main condition imposed is a velocity independent pressure drop during the deformation.
The results confirm qualitatively those obtained experimentally [3]. Moreover, the scaling relationships allow to apply two models: thermally boundary layer model with Danckvertz penetration theory and entropy based model of particle mixing.

ICHMT Digital Library

Bow shocks on a jet-like solid body shape. Thermal Sciences 2004, 2004. Pulsed, supersonic fuel jets - their characteristics and potential for improved diesel engine injection. PULSED, SUPERSONIC FUEL JETS - THEIR CHARACTERISTICS AND POTENTIAL FOR IMPROVED DIESEL ENGINE INJECTION
View of engine compartment components (left). Plots of temperature distributions in centreplane, forward of engine (right). CHT-04 - Advances in Computational Heat Transfer III, 2004. Devel... DEVELOPMENT AND CURRENT STATUS OF INDUSTRIAL THERMOFLUIDS CFD ANALYSIS
Pratt & Whitney's F-135 Joint Strike Fighter Engine under test in Florida is a 3600F class jet engine. TURBINE-09, 2009. Turbine airfoil leading edge stagnation aerodynamics and heat transfe... TURBINE AIRFOIL LEADING EDGE STAGNATION AERODYNAMICS AND HEAT TRANSFER - A REVIEW
Refractive index reconstructed field. (a) Second iteration. (b) Fourth iteration. Radiative Transfer - VI, 2010. Theoretical development for refractive index reconstruction from a radiative ... THEORETICAL DEVELOPMENT FOR REFRACTIVE INDEX RECONSTRUCTION FROM A RADIATIVE TRANSFER EQUATION-BASED ALGORITHM
Two inclusion test, four collimated sources. Radiative Transfer - VI, 2010. New developments in frequency domain optical tomography. Part II. Application with a L-BFGS associated to an inexa... NEW DEVELOPMENTS IN FREQUENCY DOMAIN OPTICAL TOMOGRAPHY. PART II. APPLICATION WITH A L-BFGS ASSOCIATED TO AN INEXACT LINE SEARCH