Hydrogen/Oxygen Propellant Densifier Using a Two-Stage Pulse Tube Cryocooler

Abstract

A unique, patent pending, thermoacoustic propellant densifier, that simultaneously densifies liquid hydrogen and liquid oxygen propellants for aerospace vehicles is introduced. The thermoacoustic densifier consists of a two-stage pulse tube cryocooler that operates at 30 Hz using helium as the working fluid. The extremely reliable pulse tube has no moving parts, is water cooled, and is acoustically driven. The pulse tube has been driven by a Thermoacoustic Stirling Heat Engine (TASHE) and a linear flexure bearing compressor. A laboratory prototype was designed, fabricated, and tested at the Sierra Lobo, Inc. facility in Milan, Ohio. Unique design features include a removable 2 nd stage for easy testing of low temperature regenerator materials and an advanced aftercooler design geometry. A system description will be presented and experimental data of the pulse tube performance will be compared with REGEN 3.2 and other analytical predictions.

Two-stage high frequency pulse tube cooler for refrigeration at 25K

“…From the pulse tube design of Nguyen et al(author?) [11], we estimated the target efficiency at T c = 25 K and T h = 300 K to η = 10% of Carnot relative to pV-power. Then Eq.…”