CFD Analysis of Turbulent Heat Transfer through Rectangular Channel on Size Optimization of Different Dimple Shape

A numerical investigation has been performed to study the effects of different dimple shapes on heat transfer and fluid flow characteristics through transversely roughened rectangular channels for Reynolds number ranging from 10000 to 30000 and subjected to uniform heat flux of 1000 W/m2. Considering single-phase approach, the two-dimensional continuity, Navier-Stokes, and energy equations developed for the physical model have been solved by using the finite volume method (FVM). The optimization was carried out by using various dimple shapes (rectangular, triangular, wedge pointing upstream, and wedge pointing downstream) in in-line and six different aspect ratios (w/e = 5, 3.334, 2.5, 2, 1.667 and 1) to reach the optimal size of the different dimple channel with maximum Performance Evaluation Criterion (PEC). In Rectangular dimple channel the maximum value of Performance Evaluation Criteria (PEC) is 1.554 at dimple height h= 6mm, Triangular dimple channel the maximum value of PEC is 2.258 at dimple height h= 5mm, wedge pointing upstream the maximum value of PEC is 1.725 at dimple height h= 4mm and wedge pointing downstream the maximum value of PEC is 1.955 at dimple height h= 4mm all the value is found at Reynolds number Re=10,000.