Variable Conductance Cold Plate for Spatial and Temporal Temperature Uniformity

In response to the 2019 NASA SBIR solicitation topic Z2.01, ldquo;Spacecraft Thermal Managementrdquo;, Advanced Cooling Technologies, Inc. proposes the development of a Variable Conductance Cold Plate to provide spatial and temporal isothermality over a 0.5 m2 area despite changes in heat load or inlet coolant temperature.nbsp; The proposed design builds on ACTrsquo;s experience with passive two-phase devices, as well as our pumped two-phase expertise, to address the needs outlined in the subtopic titled, ldquo;Mechanically Pumped Two-Phase Flow Thermal Control System Technology Developmentrdquo;.nbsp; In Phase I, ACT will design and demonstrate, through simulation and experiment, a prototype cold plate capable of managing heat fluxes up to 5 W/cm2 while maintaining spatial isothermality to within 3 K and temporal isothermality to within 0.05 K/min.nbsp; This capability results from a passive design that exploits two-phase phenomena and the unique behavior of fluids at saturation conditions.nbsp;Compared to single-phase systems at significant heat loads, two-phase thermal management systems reduce spacecraft mass, volume, and power usage while providing performance improvements such as enhanced heat transfer and temperature uniformity.nbsp; The Thermal Management Systems Roadmap (TA14) challenges researchers to develop two-phase thermal management systems that can manage high heat loads with improved temperature control. nbsp;Such systems have been described by numerous NASA research papers and, as outlined there, these systems have significant mass- and power-saving potential, as well as additional capabilities such as isothermality and heat sharing.nbsp; The purpose of the work proposed here is to support pumped two-phase thermal management system development by addressing technology gaps that are related to heat collection as identified in the referenced work and outlined in the solicitation.