The research is a fundamental investigation of heat transfer to an impinging air jet. Jet impingement is known method for high heat transfer coefficients. The most important objective of the current research wok is to conduct an investigation of the heat transfer mechanisms for an impinging air jet for combined heat sink with pin fin and dimpled surface.
The methodology of the research work is to make the use of jet air impingement to find heat transfer enhancement in dimpled flat target surface and pin fin flat surface. A target plate and its sidewalls were hung from the nozzle plate. The distance between the nozzle plate and the target plate (Z/D) was adjusted in between 4, 6 and 8 jet-diameters. Acrylic plate sidewalls were installed or removed to change the cross flow schemes such as, minimum, intermediate and maximum spent air exits.
The following sample graphical results show the comparisons between various pin-fin array arrangements similar to dimple surface for maximum spent air. Where Heat Sink 1:- 8 mm pin diameter, Heat sink 2:- 6 mm pin diameter, Heat sink 3:- 8 mm pin diameter.
Nu =Nusselt Number, Re= Reynolds Number, Z= Height of Nozzle from heat sink, D= Nozzle diameter.
It has been seen from graph that pin fin 6 mm at transfer augmentation for all Z/D ratios. Heat sink two with dimple 6 mm diameter and staggered arrangement of dimples shows maximum augmentation at Re = 6000. Further investigation in heat transfer enhancement for combined dimple and pin fin is to be carried out by experimentation