Effect on Thermal Boundary Layer, by Roughened Surface of Solar Air Heater Duct

Abstract

As is well known that, the thermo-hydraulic boundary layer formation is dependent on the surface geometry and flow of fluid through the plates used for the flow. Therefore, an experimental investigation has been carried out to study the effect on thermo-hydraulic boundary layer by using 2W (4V) type of artificial roughness geometry of the absorber plate of solar air heater. The experiments were performed to collect the data for the forced convection flow of air in solar air heater rectangular duct; with one broad wall roughened by 2W shaped ribs. The evaluation of Reynolds number has been carried out for this artificial roughness geometry, in the absorber plate of solar air heater duct. The range of parameter used in this experiment has been decided on the basis of practical consideration of the system and operating conditions. The Result has been compared with smooth duct under similar flow and boundary conditions. It is found from the investigation that on increasing the roughness of a roughened plate the Reynolds number also increases, thus increasing the turbulence of the flow.