A Mechanically Pumped Two-Phase Fluid Loop for Thermal Control Based on the Capillary Pumped Loop

Abstract

The NASA Jet Propulsion Laboratory has developed a mechanically pumped two-phase fluid loop for thermal control to enable novel mission designs and greater science return. The system is designed to be able to accommodate multiple heat loads totaling up to 500 W and is able to accommodate local fluxes up to 5 W/cm2, while maintaining a high degree of isothermally along the heat loads. Central to the system is a novel evaporator design built via additive manufacturing, which enables unique integrated wicking geometries to be integrated into a planar evaporator. In this paper results are presented from a testbed that replicates key components of the anticipated flight system. In particular the flight working fluid (ammonia) is used as well as a flight like evaporator, condenser and pump. System performance and stability is demonstrated for multiple cases, and the details of the evaporator design are discussed.