Physics-Based Models for Transient Behavior of Two Phase Flow Cooling Systems

ABSTRACT: Air Force fighter aircraft are equipped with a comprehensive sensor and communications suite that provides situational awareness, command and control and network-centric warfare capabilities. As these technologies advance, the need for avionics cooling capacity increases. Transition to a vapor compression cooling system will help meet the thermal management demands of future aircraft. Since these are two-phase flow processes, there exists a significant need for an accurate, robust simulation tool to understand the transient behavior of the two-phase cooling system under all mission operation conditions. To this end the flow regimes and heat transfer coefficients present in the system together with the impact of aircraft maneuvers must be investigated and incorporated into a simulation tool. Oceanit plans to create a robust and accurate simulation tool to predict performance of a two-phase cooling system. The tool will be fast enough to explore parameter space to understand system dynamics and aid in the design process. Our approach will use a system level model combined with computational fluid dynamics (CFD) simulations to study the transients in the cooling system. Both simulation tools are proven and validated to study the flows and heat transfer regimes present in the cooling systems of interest. BENEFIT: A simulation tool capable to predicting transient phenomena in two-phase flow loops on aircraft is important to ensure functionality is maintained for all mission conditions. All military aircraft and commercial aircraft could benefit from this technology.