Compact thermal modeling of hand-held and ultra-low power microelectronic systems has recently attracted a great deal of attention. In this study time-dependent evolution of heat transfer around a flat plate was numerically investigated. The flat plate is subjected to internal heat generation from the inner boundary via a discrete heat source. It is cooled on the outer boundary via buoyancy and radiation. The main objective of this work was to understand the limitation of a Foster RC-network in predicting transient behavior of a nonlinear system as such. Non-linearity of the system stems from the physics of flow and heat transfer evolution around the flat plate, resulting time-and power-dependent boundary conditions. Special attention was paid to the characteristics and number of the network ladders for resolving the timehistory of the temperature as a function of the input power. The studied system resembles a hand-held, fanless, device operating at room ambient.
KEY WORDS:Foster RC-network, compact thermal model, transient heat transfer, natural convection and radiation, flat plate, ther mal influence coefficients, fanless systems