An Experimental Study Of Impingement Cooling On The Surface With Pin Fins And Effusion Holes Under Maximum Crossflow Condition

Cooling is one of the most important key technologies in aero-engine design. Asincreasing inlet temperature is a method to improve thermal cycle efficiency and reducepollutant emission, more high efficient cooling technology need to be developed.Impingement has the best cooling effect of all heat removing approaches. Withmechanical processing improving and deeper research work in this filed, combinedimpinging structures have been created. But this kind of structure has more complex heattransfer characteristics as well as fickle flow field. Due to this and technology exportrestriction, few information is available in publication. Consequently, we developed apin-effusion combined impingement cooling structure. Both experiment and numericalsimulation were conducted to investigate the flow and heat transfer characteristics. Inorder to make a good comparison, we also investigated the plate impingement and pinimpingement cooling.The results shows that jet-to-plate spacing H/d=2~3has the best heat transferefficient. When the cross-flow is minor, particularly less than10%, the heat transferperformance is best. Pin can increase target plate Nusselt number, with a equal pressureresistance ratio increasing. The reason is that pin protect jet flow core, and makecross-flow pass through the feeble heat removing places. When effusion holes are addedinto pin model, the highest heat transfer performance increasing can reach50%, with aobvious pressure drop. As effusion hole diameter increasing, though discharge coefficientis improved, heat transfer characteristics become more complex. In our experiments, the5mm diameter hole has the best heat transfer performance, and next is the15mmdiameter hole. Effusion flow not only effects target plate heat transfer, but also pinsurface. More experiments and research work need to be taken to unveil the theorybeneath this complex phenomenon.