ICMIEE 18-236 Numerical Study of Heat Transfer and Flow Characteristics in a Rectangular Channel with Rib Type Turbulent Promoters

Numerical simulation is carried out to study turbulent forced convection heat transfer and friction loss for flow through a rectangular channel having a constant heat flux with different rib type turbulent promoters. The rib shapes used in this study are rectangular, triangular, trapezoidal, wedge rib upstream and wedge rib downstream. Two rib configurations: (i) ribs mounted on bottom wall and (ii) ribs mounted on both wall (staggered rib array) are simulated. Standard kε turbulence model and enhanced wall treatment are used to perform the simulation. The inflow Reynolds number is varied from 5000 to 10000. Simulation is performed for a rectangular channel with aspect ratio 13, pitch to height ratio of 4 for configuration (i) and 8 for configuration (ii), rib width to rib height ratio of 2, blockage ratio of 1/3 for configuration (i) and 1/6 for configuration (ii). The results indicate that the heat transfer performance and the friction loss are strongly affected by different rib shapes. The highest heat transfer performance is achieved for wedge rib upstream for configuration (i). For configuration (ii) highest value of heat transfer performance is obtained for triangular rib. The lowest value of heat transfer performance is obtained for wedge rib downstream for both configurations. For ribs mounted in bottom surface wedge rib downstream has the highest frictional loss and for staggered rib arrays highest frictional loss is found for wedge rib downstream. Triangular ribs mounted on both wall with staggered rib array configuration shows the highest thermal performance among the rib shapes.