Two-phase flow instability analysis for transient electronics cooling

Because of increasing power densities, refrigeration systems are being explored for two-phase cooling of ultra high power electronic components. This paper presents a framework for the transient analysis of pressure-drop refrigerant flow instabilities under both steady-state and transient imposed heat loads. Based on an analytical two-phase flow model, the system pressure and other effects on flow characteristics are quantitatively studied, so as to predict the associated flow instability margin. The most significant effect on electronics cooling system dynamics is the imposed heat load. One of the main research topics here is to study the boiling oscillatory flow responses to transient heat load changes, which can reflect the transient two-phase cooling capacity. Furthermore, the effect of wall thermal inertia on flow oscillation is systematically studied. Application-based pulsed heat load scenarios are finally evaluated. This transient instability analysis offers useful insight for future active thermal management system design.