Forced Convective Cooling Enhancement of Electronic Package Configurations Through Self-Sustained Oscillatory Flows

Abstract

Two-dimensional arrangements of electronic packages surface mounted to a printed circuit board represent grooved-channel geometries. For a certain range of Reynolds numbers, these geometries excite and sustain instabilities that are normally damped in planar Poiseuille flows. This results in a bifurcation to a self-sustained oscillatory state, which improves mixing and thereby enhances convective heat transport. Numerical simulations of the flow field and heat transfer characteristics of oscillatory and nonoscillatory flows for five grooved channels are presented. Additionally, the numerically obtained flow field corresponding to a suspended electronic package is analyzed. The extent of heat transfer enhancement is gauged through direct comparison to results corresponding to the steady-flow regime. Local heat transfer coefficients are determined and used to calculate the temperature distribution within a surface-mounted package. Moreover, the importance of using locally-defined instead of spatially-averaged heat transfer coefficients for thermal design and analysis of electronic packages is discussed.