Liquid hydrogen mass flow through a multiple orifice Joule-Thomson device

“…5). This expansion is described through the fluid pressure drop ∆P of the vented branch based on the mass flow rate ṁTVS and on the JT-valve pressure drop constant K JT (characterizing the JT-valve geometry (17)) :…”

Section: Appendix a Tvs Components Formulationmentioning

confidence: 99%

Optimal design of a Thermodynamic Vent System for cryogenic propellant storage

et al. 2016

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“…The resistance to flow in Visco Jets is measured in liquid ohms -or "Lohm", a term coined by the manufacturer. NASA has previously tested Visco Jets in LN 2 [7], LH 2 [1,2,8], LO 2 [9] and LCH 4 [10]. Based on the expected flow rates, Visco Jets used for these tests were rated at 8,200 and 41,000 Lohm, with expected flow rates from 0.14 to 0.82 kg/hour.…”

Section: Test Hardwarementioning

confidence: 99%

Clogging of Joule-Thomson Devices in Liquid Hydrogen—lunar Lander Descent Stage Operating Regime

Jurns¹,

Weisend²

2010

AIP Conference Proceedings

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Joule-Thomson (J-T) devices have been identified as critical components for future space exploration missions. The NASA Constellation Program lunar architecture considers LOX/LH 2 propulsion for the lunar lander descent stage main engine an enabling technology, ensuring the cryogenic propellants are available at the correct conditions for engine operation. This cryogenic storage system may utilize a Thermodynamic Vent System (TVS) that includes J-T devices to maintain tank fluid pressure and temperature. Previous experimental investigations have indicated that J-T devices may become clogged when flowing LH 2 while operating at a temperature range from 20.5 K to 24.4 K.It has been proposed that clogging is due to a trace amount of metastable, supercooled liquid neon in the regular LH 2 supply. In time, flow blockage occurs from accretion of solid neon on the orifice.This clogging poses a realistic threat to spacecraft propulsion systems utilizing J-T devices in cryogenic pressure control systems. TVS failure due to J-T clogging would prevent removal of environmental heat from the propellant and potential loss of mission.This report describes J-T clogging tests performed with LH 2 . Tests were performed in the expected Lunar Lander operating regime, and several methods were evaluated to determine the optimum approach to mitigating the potential risk of J-T clogging.

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“…The Joule-Thomson valve or pressure orifice for this vent flow rate was chosen using equations developed during a cryogenic nitrogen mass flow test. 3 Spreadsheets were created to size the pressure orifice, determine the vent fluid quality of the throttled nitrogen through the J-T valve, determine the flow rate of the cold nitrogen, and determine the heat transfer in the heat exchanger.…”

Section: Test Hardwarementioning

confidence: 99%

Thermodynamic Vent System Test in Low Earth Orbit Simulation

Vanoverbeke

2004

40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit

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Liquid hydrogen mass flow through a multiple orifice Joule-Thomson device

Cited by 3 publications

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Optimal design of a Thermodynamic Vent System for cryogenic propellant storage

Optimal design of a Thermodynamic Vent System for cryogenic propellant storage

Clogging of Joule-Thomson Devices in Liquid Hydrogen—lunar Lander Descent Stage Operating Regime

Thermodynamic Vent System Test in Low Earth Orbit Simulation

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