The fast development in electronics has resulted in faster and faster computers. Furthermore, the electronic components trend to get smaller and smaller by the year. With more processing power combined with smaller components the heat generation rapidly increases. The scope of this study is to examine a spot cooling technique consisting with different geometry of multiple impinging jets in combination with a cross-flow by the use of CFD. The case is limited to a heated wall mounted cube cooled by a impinging jet as well as an multiple impinging jets in a low velocity cross-flow. This study can be divided into two parts a verification study and a detailed study. The verification study consist of comparison between RSM model and measured values for both the turbulent flow and the surface temperature. The single impinging mesh consists of 934 k elements while the plus 1439 k and cross consists of 2809 k elements. All the meshes are created in ANSYS fluent and this paper contains a detailed guide to create them. The verification study proved that RSM can predict the complicated flow with good agreement with the single impinging jet. The heat transfer coefficient differ substantially between the cases. The PIV compared to the UDF for the inlet velocity profiles had a 21\% increase in heat transfer coefficient in the top layer of the cube. In all the simulations the cross had at least an increase of 18\% on average \(h\). While there was no real verification study for the multiple impinging jets I would still argue that cross is better than the plus sign geometry in terms of heat transfer.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:hig-21851 |
| Date | January 2016 |
| Creators | Johansson, Robert |
| Publisher | Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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