Experimental Investigation of Heat Transfer Enhancement by Pulsating Flow in a Minichannel

Abstract

The increasing power density requirements of next generation high performance electronic devices has resulted in ever-increasing heat flux densities which necessitates the evolution of new liquid-based heat exchange technologies. Pulsating flow in single-phase cooling systems is viewed as a potential solution. In this study, an experimental analysis of thermally developed pulsating flow in a rectangular minichannel is conducted. The channel test setup involves a heated bottom section approximated as a constant heat flux boundary. Asymmetric sinusoidal pulsating flows with a fixed flow rate amplitude ratio of 0.9 and Womersley numbers (Wo) of 0.51 and 1.6 are investigated. The wall temperature profiles are recorded using infrared thermography. It is observed that the transverse wall temperature profile is influenced by the sudden velocity variations of such characteristic waveforms. A heat transfer enhancement of 6% was determined for asymmetric flow pulsations of Wo > 1 over the steady flow with a potential augmentation for higher flow rate amplitudes.