Abo Bibliothek: Guest

# PRESSURE DROP AND HEAT TRANSFER IN A MINICHANNEL FLOW SYSTEM INVOLVING TWO STRAIGHT SECTIONS SEPARATED BY A 90° BEND

DOI: 10.1615/ICHMT.2004.CHT-04.650
page 14

Patrick H. Oosthuizen
Department of Mechanical and Materials Engineering, Queen's University, 130 Stuart Street, Kingston, ON, K7L 3N6, Canada

## Abstrakt

Incompressible flow through a minichannel (here taken to imply a channel with a size that is of the order of 1 mm with flows that are such that the Reynolds number is between about 1 and 1000) system have been considered in the present study. The channel has a rectangular cross-section. The flow enters the channel with a uniform velocity and passes through a straight channel section that has a length that is 30 times the width of the channel. The flow then passes around a 90° bend. Following the bend, the flow passes down another straight channel which also has a length of 30 times the width of the channel. A uniform heat flux is applied over the entire surface of the duct. The flow geometry does not represent any that is likely to occur in minichannel system applications but is adequate for the evaluation of the assumptions often adopted regarding pressure losses, flow development length and heat transfer rates in real systems. It has been assumed that the flow is steady, that the flow is incompressible, that the velocity and temperature are uniform over the channel inlet plane, and that there is no slip on the channel boundaries. The governing equations have been written in dimensionless form. Solutions to these dimensionless governing equations have obtained using a commercial finite-element software package, FIDAP. The solution has the following parameters: the Reynolds number, Re, the Prandtl number, Pr, the height-to-width ratio of the channel cross-section, H, and the dimensionless radius of the bend Ri = ri/w where w is the width of the channel and ri the radius of the inside surface of the bend. Results are only presented here for Pr = 0.7 and Ri= 1. Re values between 10 and 500 and Hvalues between 0.5 and 2 have been considered. The effect of the governing parameters on the pressure losses, flow development lengths and heat transfer rates has been studied.

## 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