Author
Abstract
The heat transfer rate and pressure drop characteristics of turbulent flow of air
through uniformly heated circular tube fitted with drilled cut conical rings with
three space ratios (X=5.4, 6.4, and 8.4) have been studied experimentally. The flow
characteristics are governed by space ratio (the ratio of the distance between drilled
conical ring and the inner diameter of tube), Reynolds number, and drilled conical
ring diameter to inner diameter of tube. The goal of the present work is to
investigate the effect of drilling of the cut conical ring turbulators (with constant
ring to tube diameter ratio) and space ratio on heat transfer, friction factor, and
enhancement efficiency under ranging of Reynolds number from 5000 to 23500.In
addition, correlation for Nusselt number, friction factor and performance
evaluation criteria to assess the real benefits in using the drilled-conical ring
turbulator of the enhanced tube are determined. The results show that the process
of drilling of the conical ring inside tube gives high rates of heat transfer more than
that in the conical ring without drilling.
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