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ISSN Online: 2377-424X

ISBN Print: 0-89116-909-1

International Heat Transfer Conference 9
August, 19-24, 1990 , Jerusalem, Israel

UNSTEADY FORCED CONVECTION IN DUCTS FOR A SINUSOIDAL VARIATION OF INLET TEMPERATURE

Get access (open in a dialog) DOI: 10.1615/IHTC9.2520
pages 265-270

摘要

An experimental apparatus has been designed, built and used to study the behavior of unsteady forced convection of thermal entrance region in a duct with a rectangular cross section due to a sinusoidal inlet temperature. A wide range of Reynolds numbers (Re) and the frequency of inlet temperature (i>β)(450<Re<20,000 and 0.01 Hz<β<0.2 Hz) is covered. Experiments are carried out in the thermal entrance region with fully developed velocity profile and in the combined entrance region. The temperature variation at several locations along the duct is measured and recorded for various Reynolds numbers and frequencies of inlet temperature.
Part of the experimental results are compared with the theoretical investigation to check the validity and accuracy of the theoretical study. The theoretical study of laminar forced convection in a rectangular duct, subjected to a sinusoidally varying inlet temperature is also presented. A general boundary condition of fifth kind that accounts for both external convection and wall thermal capacitance effects is considered. Reasonable agreement has been obtained when nonuniform inlet temperature profile is considered.