creator Ma, Weicong 2019 Spring 2019 Thesis Illinois Institute of Technology MMAE / Mechanical, Materials, and Aerospace Engineering advisor Acharya, Sumanta Mechanics Fluid mechanics Cooling Technique Fluid Heat transfer Jet Impingement Microjets Turbulence en An experimental investigation of a single main jet with surrounding microjets impinging on a flat heated surface was performed to understand the role of the higher-speed microjets on the surface heat transfer. Eight microjets 45-degrees apart were fabricated on a circular disk mounted at the exit of the main jet axisymmetric. Heat transfer enhancement on the flat surface was evaluated by comparison with the results of a baseline single round jet with the same flow rate. The average Nusselt Number and the local Nusselt number in the radial direction are reported as functions of dimensionless nozzle-to-plate distance, dimensionless radial distance, and dimensionless mass flow rate ratio. Local Nusselt number contours are plotted as a function of radial position. The area-averaged Nusselt number and local Nusselt number beyond the near-field impingement jet region increases monotonically with increasing mass flow rate ratio and decreasing of nozzle-to-target distance. The local Nusselt number at the stagnation region shows a more complex behavior with the mass flow rate ratio and nozzle-to-target distance. born digital application/pdf In Copyright http://rightsstatements.org/page/InC/1.0/ Restricted Access http://hdl.handle.net/10560/islandora:1000845