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

Grooved-channel geometries are formed when electronic components are directly mounted to a substrate. Some grooved-channel geometries have been found to excite and sustain the normally damped instabilities present in Poiseuille flows at lower Reynolds numbers than indicated by linear stability analysis. The resulting selfsustained oscillatory flows improve mixing and thereby enhance convective heat dissipation. Numerical simulations of the flow field and heat transfer characteristics of oscillatory and non-oscillatory flows for five grooved-channel and one suspended block geometry are presented. 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. Furthermore, the importance of using locally-defined heat transfer coefficients instead of spatially-averaged coefficients for thermal design and analysis is discussed. This work was supported by the Engineering Design Research Center, a National Science Foundation / Engineering Research Center, under cooperative agreement EDC-8943164 and by the National Science Foundation Grant CTS-8908808.