2022-04-112022-04-112012-06Yemenici, O. vd. (2012). "An experimental investigation of flow and heat transfer characteristics over blocked surfaces in laminar and turbulent flows". International Journal of Heat and Mass Transfer, 55(13-14), 3641-3649.0017-93101879-2189https://doi.org/10.1016/j.ijheatmasstransfer.2012.02.064https://www.sciencedirect.com/science/article/pii/S0017931012001275?via%3Dihub#!http://hdl.handle.net/11452/25686Flow and heat transfer measurements were obtained over a blocked surface mounted on a low speed wind tunnel in order to investigate the combined the effects of free stream velocities and the different size of rectangular blocks on the flow and heat transfer characteristics. Mean velocity and turbulence intensities were measured by a constant temperature anemometer and wall temperatures by copper-constant thermocouple and static pressures by a micro-manometer, respectively. It was found that the flow separations and reattachments were occurred before the first blocks, on the first blocks, between blocks and after the last blocks. The blocked surface area and flow separation caused not only heat transfer enhancement but higher turbulence levels as well. The average Stanton numbers, for block heights of 10, 15 and 20 mm, were higher than those of flat surface by 82%, 95%, 113% in laminar and 27%, 38%, 50% in turbulent, respectively. These results showed that heat transfer enhancement on the blocked surface increased with block heights and become more pronounced in laminar than that of turbulent flows.eninfo:eu-repo/semantics/closedAccessThermodynamicsEngineeringMechanicsBlocked surfaceSeparationConvective heat transfer3-dimensional blocks2-dimensional ribsConvective flowParallel platesFluid-flowChannelEnhancementSimulationObstacleSeriesFlow separationHeat transfer coefficientsThermocouplesConstant-temperature anemometersConvective heat transferDifferent sizesExperimental investigationsFlat surfacesFlow and heat transferFree-stream velocityHeat Transfer enhancementLaminar and turbulent flowLow-speed wind tunnelMean velocitiesReattachmentRectangular blockStanton numbersStatic pressureSurface areaTurbulence intensityTurbulence levelWall temperaturesTurbulent flowArticle0003047859000312-s2.0-84859647667364136495513-14ThermodynamicsEngineering, mechanicalMechanicsNusselt Number; Mixed Convection; Heat Transfer Enhancement