Simulation of a gaseous jet impinging on a convex heated surface – effect of inlet condition

FlowandheattransferduetoaNitrogenjetatambienttemperatureimpingingonanisothermallyheated convexsurfacearenumericallyinvestigatedandcomparedtoexperimentalmeasurementsobtainedfrom a similar configuration. The temperature difference between the jet and the surface reaches up to 580K and the nozzle-to-surface distance is equal to the nozzle diameter. On account of the small nozzle-tosurfacedistanceandnozzlelength,flowandheattransferovertheimpingingsurfacearehighlysensitive to the nozzle inlet conditions; therefore, in this study various inlet conditions are examined and compared.Duetohightemperaturevariation,changesof densityareaccountedforusingacompressiblesolver instead of constant property approach, widely used in the literature. For the same reason, temperature dependence of fluid properties is included in the solution. The agreement between the solution and experiments is reasonable, and mean velocity profile is found to have significant influence on surface heat transfer (up to 25% difference in stagnation point Nusselt number among different profiles).