EXPERIMENTAL AND NUMERICAL CONVECTIVE HEAT TRANSFER INVESTIGATION IN LAMINAR RECTANGULAR-CHANNEL FLOW ACROSS V-SHAPED GROOVES

Abstract

The influence of staggered V-grooves on the hydrothermal performance of a rectangular-channel flow is systematically investigated through a combination of numerical and experimental approaches. The 3-D numerical simulation is developed adopting computational fluid dynamics (CFD) (ANSYS FLUENT) for a range of Reynolds numbers (Re) from 100 to 1000. The experiments are conducted on straight and V-grooved channels (with pitch-to-height and height-to-hydraulic diameter ratios of 2 and 0.75) for distilled water under constant wall heat flux conditions to validate the computational model. Additionally, the impact of V-shaped groove arrangements, forward V-grooved channel (FVGCH) and backward V-grooved channel (B-VGCH), on the flow and heat fields, as well as the effect of groove depths (<i>d</i> &#61; 1.5, 2.5, and 3.5 mm), are also studied. In both experimental and numerical results, the performance evaluation criterion (PEC) grows with rising Reynolds numbers. The highest PEC values of the numerical and experimental findings for the F-VGCH are 2.18 and 2.29, respectively, at Re &#61; 1000. Whereas the highest PEC values of the numerical and experimental results for the B-VGCH are 1.81 and 1.96, respectively, at the same Re (Re &#61; 1000). In addition, the values of PEC for F-VGCH are greater than the PEC values of B-VGCH for all examined groove depths over the entire range of Reynolds numbers. Thus, the F-VGCH offers the best performance evaluation criterion in comparison with B-VGCH.