Detailed Investigation on Rib Turbulated Flow Inside a Rectangular Duct

Abstract

Rib turbulators are the most intensively studied passive technique, which promotes near wall turbulence in the internal cooling passages of heat transfer devices. However, there exists the tradeoff between the pressure penalty and heat transfer enhancement. For suggesting a correct rib configuration for particular application, it is necessary to understand the flow mechanism behind rib tabulators. For this purpose an experimental setup has been designed to investigate the detailed flow field and corresponding effect on heat transfer characteristics using Particle Image Velocimetry and Liquid Crystal Thermography respectively. In the literature the detailed flow field investigation as well as the thermal characterizations behind the rib other than rectangular/square cross sectional shape is found to be limited. The present work is an experimental investigation inside a rectangular duct for flow behind the trapezoidal type of rib with changing angle at different Reynolds numbers. The emphasis is towards assessing the potential impact of varying chamfering angle over the flow structures and its subsequent effect on heat transfer enhancement as well as in obviating the hot spots in the vicinity behind the chamfered rib turbulators.