Experimental investigations heat transfer and pressure drop characteristics of flow through circular tube fitted with drilled cut-conical rings

الملخص EN

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.