Numerical and Experimental investigation of heat transfer of triangular ribs in divergent duct

In this work, numerical and experimental investigation has been carried out to obtain detailed heat transfer distributions for a diverging channel with and without enhancement features. The cooling configurations considered include rib turbulators of triangular cross section on the main heat transfer surface. All of the measurements are presented at a range of Reynolds number from 6560 to 13100. Pressure drop measurements for the overall channel are also presented to evaluate the heat transfer enhancement geometry with respect to the pumping power requirements. Various geometrical parameters such as angle of attacks of ribs (90, 45 & 30), rib spacing i.e.(P/e= 6,8,10,12), rib heights (e=3, 4,5,6mm), and comparison of triangular shaped rib with square shaped rib for the same boundary conditions have been studied numerically for the different heater inputs. This numerical analysis of the results shows that the triangular ribs oriented at 45 angle of attack, with P/e=8 and with rib height of 3mm provides significantly higher heat transfer performance than plain plate. It is concluded that there is increase in thermal performance of 20% to 30% by the use of triangular ribs.