Experimental investigation of electronics cooling with impinging jet and crossflow

Impinging jets are frequently used in various applications such as annealing of metals, cooling of gas turbine blades and cooling of electronic systems that produce high amounts of heat. Electronic printed circuit boards contain multiple parts with different thermal loads and to ensure long-term safe operation, it is crucial to cool the electronic components with an appropriate cooling method. Cooling of high heat dissipating components with local impinging jets and cooling of other components with channel flow (crossflow) is an alternative to conventional channel flow cooling. Within the scope of this thesis, experimental investigations have been carried out for different jet nozzle geometries, nozzle aspect ratios, jet/crossflow velocity ratios and jet to target component distances for electronics cooling with confined turbulent impinging air jet and crossflow. The effects of the described parameters on the flow and heat transfer are examined and presented. It is observed that impinging jets provide better cooling performance compared to conventional channel flow, and crossflow affects jet flow development when the velocity ratio is less than 5. It is found that changes in the nozzle geometry are effective on the heat transfer from the target surface and nozzles with low AR values improve heat transfer by 20% - 50% compared to circular nozzles under the same conditions due to lesser deflection.