Johansen, CraigPark, SimonElliott, Mark2018-01-192018-01-192018-01-08Elliot, M. (2018). Effect of Surface Treatment on the Rate of Convective Heat Transfer for a Cylinder in Crossflow (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.http://hdl.handle.net/1880/106280A method of roughening the surface of cylinders by media-blasting with micron scale particles was tested for heat transfer enhancement and pressure drop characteristics with an air flow over a range of Reynolds numbers from 200 to 7000. It was found that the surface treatment had an adverse effect on the rate of convective heat transfer over a range of Reynolds numbers. However, over the same range, the surface pressure drop was unaffected by the surface treatment. The pressure data likely indicates that the stream turbulence of the oncoming air flow was high enough to cause the critical Reynolds number to drop to the lower end of the Reynolds number range and nullify any positive effects that a roughened surface might have. Lower Nusselt numbers for the blasted wires suggest that for flows with high free-stream turbulence intensity a roughened surface decreases heat transfer. This decrease is possibly caused by earlier turbulent boundary layer separation on the rough surface due to the fact that the flows are all in the trans-critical flow regime at every Reynolds number tested.enUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.Heat TransferFluid MechanicsHeat ExchangerEngineering--AerospaceEngineering--Mechanicalmaster thesis10.11575/PRISM/5361