numerical heat transfer study of turbulent square-duct flow through inline v-shaped discrete ribs

a numerical work has been conducted to examine turbulent periodic flow and heat transfer characteristics in a three dimensional square-duct with inline 60° v-shaped discrete thin ribs placed on two opposite heated walls. the isothermal-flux condition is applied only to the upper and lower duct walls while the two sidewalls are insulated, similar to internal passage cooling of gas turbine blades. the computations are based on the finite volume method with the simple algorithm for handling the pressure–velocity coupling. air is the working fluid with the flow rate in terms of reynolds numbers ranging from 10,000 to 25,000. the numerical result is validated with available square-rib measured data and found to agree well with measurement. the computation reveals that the ribbed duct flow is fully developed periodic flow and heat transfer profiles at about x/d = 7–11 downstream of the inlet. effects of different rib height to duct diameter ratios, br, on thermal characteristics for a periodic ribbed duct flow are investigated.