Turbulent Heat Transfer and Pressure Drop in an Internally Ribbed Rectangular Duct

Computational study was carried out to determine average heat transfer coefficients and friction factors for turbulent flow through rectangular ducts with ribs. A commercial finite volume package ANSYS FLUENT 12.1 is used to analyze and visualize the nature of the flow across the ribbed duct The fluid in the duct was air, and the average heat transfer coefficients were determined by measuring the overall heat transfer coefficients of the duct. To attain fully developed conditions at the entrance and exit, the duct was built with additional lengths before and after the test section. The walls of the air side were ribbed with an array of short ribs. The second wall of the duct was well insulated and can be considered adiabatic. The results are presented in dimensionless form, in terms of Nusselt numbers and friction factors as functions of the Reynolds number. It was found that the ribs increase both the heat transfer and the pressure drop compared with a smooth duct.