Performance study on turbulent heat transfer using rectangular air duct integrated with continuous and intermittent ribs turbulators

Abstract

To continue the scientific path specialized in enhancing the thermal performance of thermal systems, several tests are carried out to improve the overall performance of a rectangular duct as air flows through it. This study reports experimentally and numerically the heat transfer enhancement and overall performance of a rectangular air duct with various arrangement of continuous and intermittent ribs turbulators. The ribs are inserting in several array arrangements at a 90o relative to the direction of flow. Three ribs lengths s= 30, 60 and 150 mm employed with the several arrangements that?s tested in the current study, with the pitch ratios (p/e)= 5.0 and height ratios (e/H) = 0.330. These cases include: continuous ribs case (CR), intermittent-continuous-intermittent ribs case (ICIR) and intermittent-ribs (IR). Reynolds number (Re) is ranging from 10,000 to 35,000. The experimental work was performed by designed and fabricated test rig while the numerical work was performed in commercially ANSYS Fluent 17.2. the outcomes show that (IR) case offers the best overall performance for all tested velocities, its 1.54 for experimental study and 1.57 for numerical study at Re=10000. Also, the highest friction factor values are found in (IR) case, it is found to be 0.082 in Re=10000.