Enhanced impingement cooling using nozzles with modified exit geometries for active heat sinks

Thermal management of high power electronic components with dissipation ratings of over 5 W/cm² clearly demands high performance cooling techniques. Work, both experimental and/or analytical, is presented in this paper using enhanced impingement cooling as active heat sink for electronic component or their boards. Impinging jets (open pipes, for example) have been extensively used for high heat removal/transfer rates from surfaces. Due to its simplicity, impingement nozzles are good candidates for further performance improvements. This paper presents surface pressure and heat transfer data from two novel nozzle configurations: the nozzle with tabs and the radial nozzle. These involve simple exit geometry modifications. Results indicate that higher heat transfer rates are indeed achieved using nozzles with modified exit geometries. Typical increases in surface convective heat transfer coefficients of the order of 10-15% over plain impingement jets were recorded. Surface pressures also indicate marked reduction from those obtained using traditional nozzle exit lips