Heat transfer augmentation in a microchannel heat sink with sinusoidal cavities and rectangular ribs

A three-dimensional numerical simulation was conducted to study the characteristics of fluid flow and heat transfer in new design of microchannel heat sink with sinusoidal cavities and rectangular ribs (MC-SCRR) for Reynolds number ranging from 100 to 800. A comparative analysis has conducted to the performance of the proposed design with related geometries such as microchannel with rectangular ribs MC-RR and microchannel with sinusoidal cavities MC-SC. The results showed that thermal performance of MC-SCRR is superior over both MC-RR and MC-SC. The new design of MC-SCRR has proved the ability to combine between two important features; large flow area which significantly reduces the pressure drop and high flow disturbances which caused by existence of ribs in the central portion of channel. The overall performance of MC-SCRR is evaluated in term of friction factor, Nusselt number and performance factor. The effect of three geometrical parameters; relative cavity amplitude (λ) relative rib width (β) and relative rib length (Γ) on the convective heat transfer and pressure drop have been investigated. The performance factor Pf for MC-SCRR with λ = 0.15, β = 0.13 and Γ = 0.5 achieves 1.85 at Re = 800.