A comparison of the heat transfer and friction factor performance of four different types of artificially roughened surface

Abstract A comparison is made of the heat transfer and friction factor performance of four different types of artificially roughened surface. Each surface has near-optimum thermal performance for its own particular type of roughness. These roughened surfaces have been developed and tested as part of nuclear reactor research programmes with the object of improving the rate of heat removal from fuel pins in gas-cooled reactors. The empirical data are taken from single pin tests using gaseous coolants. The comparison of thermal performance is made on the basis of transformed data, with some extrapolation using roughness parameter techniques. A discussion is included on other factors which may be important in the selection of an artificially roughened surface for practical use.