Search NASA⌕ Search

SEARCH · Search NASA

Results for “VACUUM CHAMBER”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Vacuum chamber pressure effects on thrust measurements

Tests were conducted to investigate the effect of vacuum facility pressure on the performance of small thruster nozzles. Thrust measurements of two converging-diverging nozzles with an area ratio of 140 and an orifice plate flowing unheated nitrogen and hydrogen were taken over a wide range of vacuum facility pressures and nozzle throat Reynolds numbers. In the Reynolds number range of 2200 to 12,000 there was no discernable viscous effect on thrust below an ambient to total pressure ratio of 1000. In nearly all cases, flow separation occurred at a pressure ratio of about 1000. This was the upper limit for obtaining an accurate thrust measurement for a conical nozzle with an area ratio of 140.

Sovey, J. S.↗
NASA NTRS1985

Vacuum chamber pressure effects on thrust measurements of low Reynolds number nozzles

Tests were conducted to investigate the effect of vacuum facility pressure on the performance of small thruster nozzles. Thrust measurements of two converging-diverging nozzles with an area ratio of 140 and an orifice plate flowing unheated nitrogen and hydrogen were taken over a wide range of vacuum facility pressures and nozzle throat Reynolds numbers. In the Reynolds number range of 2200 to 12 000 there was no discernable viscous effect on thrust below an ambient to total pressure ratio of 1000. In nearly all cases, flow separation occurred at a pressure ratio of about 1000. This was the upper limit for obtaining an accurate thrust measurement for a conical nozzle with an area ratio of 140.

Sovey, J. S.↗
NASA NTRS1986

Vacuum chamber pressure effects on thrust measurements of low Reynolds number nozzles

Tests were conducted to investigate the effect of vacuum facility pressure on the performance of small thruster nozzles. Thrust measurements of two converging-diverging nozzles with an area ratio of 140 and an orifice plate flowing unheated nitrogen and hydrogen were taken over a wide range of vacuum facility pressures and nozzle throat Reynolds numbers. In the Reynolds number range of 2200 to 12,000 there was no discernable viscous effect on thrust below an ambient to total pressure ratio of 1000. In nearly all cases, flow separation occurred at a pressure ratio of about 1000. This was the upper limit for obtaining an accurate thrust measurement for a conical nozzle with an area ratio of 140.

Sovey, J. S.↗
NASA NTRSDate not supplied

Dual Glovebox Thermal Vacuum Chamber: Testing Capabilities for Spacesuit Arms and Gloves

The development of Extravehicular Activity (EVA) suits and hand mobility EVA tasks are complex, high risk, and difficult to test in a simulated space environment. During the early assembly of the International Space Station (ISS), the Crew and Thermal Systems Division (CTSD) at NASA Johnson Space Center (JSC) was tasked to design a chamber that could use two Extravehicular Mobility Unit (EMU) arms and gloves in a simulated space environment versus testing with a full suit. The Dual Glovebox (DGB) Chamber was built and served to help develop EVA tools and operations to assist with Return to Flight for the Space Shuttle after the Columbia accident. With the recent development of the Exploration Extravehicular Mobility Unit (xEMU) and new commercial suits through the Extravehicular Activities Services (xEVAS) contract, the DGB can support the need to do suit component testing at thermal extremes and EVA operations without the cost of full suit testing. The DGB can simulate realistic delta pressures, vacuum down to 5x10-4 Torr (0.066 Pa) with roughing and cryogenic pumps, and a wide range of temperatures achieved via a combination of Liquid Nitrogen (LN2), conditioned Gaseous Nitrogen (GN2), Infrared (IR) lamps, and heater cables. Recent developmental work has verified operational status of the chamber and expanded the capabilities of the DGB to include thermal contact testing of suit gloves through two temperature-controlled grab bars. This paper will discuss the history and capabilities of the DGB, and the chamber’s future role in the development of new spacesuit systems.

spacesuit arms↗
NASA NTRSDate not supplied

Cryogenic Vacuum Chamber Testing of A Conductively-Cooled, High Temperature Superconducting Rotor for a 1.4 MW Electric Machine for Aeronautics Applications

This paper presents the first ever demonstration of a superconducting rotor cooled conductively without a cryogenic fluid or solid. The full-scale rotor was operated statically in its intended environment – about 1e-3 torr vacuum with only conductive cooling through mechanical connections to a cryocooler contained on the rotor. Stable operation of the rotor in a representative magnetic environment was demonstrated up to its rated direct current (57.2 A) and the designed temperature limit for the superconductor (62 K). Additional electrical measurements increased confidence that the superconducting coils functioned as intended. A collection of steady state temperature distributions was measured at operating and non-operating conditions. In all but one case, the observed temperature gradient between the cold tip and superconducting coils satisfies the design but with little margin. Opportunities to reduce the gradient are identified.

Electrified aircraft propulsion↗
NASA NTRSDate not supplied

Cryogenic Vacuum Chamber Testing of A Conductively-Cooled, High Temperature Superconducting Rotor for a 1.4 MW Electric Machine for Aeronautics Applications

This paper presents the second ever demonstration of a superconducting rotor cooled only via conductive connection to a cryocooler, i.e., without pumped or solid cryogens. The fullscale rotor was operated statically in its intended environment – about 1e-3 torr vacuum with only conductive cooling through mechanical connections to a cryocooler contained on the rotor. Stable operation of the rotor in a representative magnetic environment was demonstrated up to its rated direct current (57.2 A) and the designed temperature limit for the superconductor (62 K). Additional electrical measurements increased confidence that the superconducting coils functioned as intended. A collection of steady state temperature distributions was measured at operating and non-operating conditions. In all but one case, the observed temperature gradient between the cold tip and superconducting coils satisfies the design but with little margin. Opportunities to reduce the gradient are identified.

Electrified aircraft propulsion↗
NASA NTRS2024

Dual Glovebox Thermal Vacuum Chamber: Testing Capabilities for Spacesuit Arms and Gloves

The development of Extravehicular Activity (EVA) suits and hand mobility EVA tasks are complex, high risk, and difficult to test in a simulated space environment. During the early assembly of the International Space Station (ISS), the Crew and Thermal Systems Division (CTSD) at NASA Johnson Space Center (JSC) was tasked to design a chamber that could use two Extravehicular Mobility Unit (EMU) arms and gloves in a simulated space environment versus testing with a full suit. The Dual Glovebox (DGB) Chamber was built and served to help develop EVA tools and operations to assist with Return to Flight for the Space Shuttle after the Columbia accident. With the recent development of the Exploration Extravehicular Mobility Unit (xEMU) and new commercial suits through the Extravehicular Activities Services (xEVAS) contract, the DGB can support the need to do suit component testing at thermal extremes and EVA operations without the cost of full suit testing. The DGB can simulate realistic delta pressures, vacuum down to 5x10-4 Torr (0.066 Pa) with roughing and cryogenic pumps, and a wide range of temperatures achieved via a combination of Liquid Nitrogen (LN2), conditioned Gaseous Nitrogen (GN2), Infrared (IR) lamps, and heater cables. Recent developmental work has verified operational status of the chamber and expanded the capabilities of the DGB to include thermal contact testing of suit gloves through two temperature-controlled grab bars. This paper will discuss the history and capabilities of the DGB, and the chamber’s future role in the development of new spacesuit systems.

Extravehicular Activity (EVA)↗
NASA NTRSDate not supplied

Dual Glovebox Thermal Vacuum Chamber: Testing Capabilities for Spacesuit Arms and Gloves

The development of Extravehicular Activity (EVA) suits and hand mobility EVA tasks are complex, high risk, and difficult to test in a simulated space environment. During the early assembly of the International Space Station (ISS), the Crew and Thermal Systems Division (CTSD) at NASA Johnson Space Center (JSC) was tasked to design a chamber that could use two Extravehicular Mobility Unit (EMU) arms and gloves in a simulated space environment versus testing with a full suit. The Dual Glovebox (DGB) Chamber was built and served to help develop EVA tools and operations to assist with Return to Flight for the Space Shuttle after the Columbia accident. With the recent development of the Exploration Extravehicular Mobility Unit (xEMU) and new commercial suits through the Extravehicular Activities Services (xEVAS) contract, the DGB can support the need to do suit component testing at thermal extremes and EVA operations without the cost of full suit testing. The DGB can simulate realistic delta pressures, vacuum down to 5x10-4 Torr (0.066 Pa) with roughing and cryogenic pumps, and a wide range of temperatures achieved via a combination of Liquid Nitrogen (LN2), conditioned Gaseous Nitrogen (GN2), Infrared (IR) lamps, and heater cables. Recent developmental work has verified operational status of the chamber and expanded the capabilities of the DGB to include thermal contact testing of suit gloves through two temperature-controlled grab bars. This paper will discuss the history and capabilities of the DGB, and the chamber’s future role in the development of new spacesuit systems.

Extravehicular Activity (EVA)↗
NASA NTRSDate not supplied

Dual Glovebox Thermal Vacuum Chamber: Testing Capabilities for Spacesuit Arms and Gloves

The development of Extravehicular Activity (EVA) suits and hand mobility EVA tasks are complex, high risk, and difficult to test in a simulated space environment. During the early assembly of the International Space Station, the Crew and Thermal Systems Division at NASA JSC was tasked to design a chamber that could use two Extravehicular Mobility Unit (EMU) arms in a simulated space environment versus testing with a full suit. The Dual Glove Box (DGB) Chamber was built and served to help develop EVA tools and operations to assist with Return to Flight for the Space Shuttle after the Columbia accident. With the recent development of the Exploration Extravehicular Mobility Unit (xEMU) and new commercial suits through the Extravehicular Activities Services (xEVAS) contract, the DGB can support the need to do suit component testing at thermal extremes and EVA operations without the cost of full suit testing. The DGB can simulate realistic delta pressures, vacuum down to 10^-5 Torr with roughing and cryogenic pumps, and a wide range of shroud temperatures achieved via a combination of Liquid Nitrogen (LN2), conditioned Gaseous Nitrogen (GN2), Infrared (IR) lamps, and heater plates. Recent developmental work has verified operational status of the chamber and expanded the capabilities of the DGB to include thermal contact testing of suit gloves through the development of 2 temperature-controlled grab bars. This paper will discuss the history and capabilities of the DGB, and the chamber’s future role in the development of new spacesuit systems.

Extravehicular Activity (EVA) suits↗
NASA NTRSDate not supplied

Dual Glovebox Thermal Vacuum Chamber: Testing Capabilities for Spacesuit Arms and Gloves

The development of Extravehicular Activity (EVA) suits and hand mobility EVA tasks are complex, high risk, and difficult to test in a simulated space environment. During the early assembly of the International Space Station, the Crew and Thermal Systems Division’s Systems Test Branch at NASA JSC was tasked to design a chamber that could use two Extravehicular Mobility Unit (EMU) arms in a simulated space environment versus testing with a full suit. The Dual Glove Box (DGB) Chamber was built and served to help develop EVA tools and operations to assist with Return to Flight for the Space Shuttle after the Columbia accident. With the recent development of the Exploration Extravehicular Mobility Unit (xEMU) and new commercial suits through the Extravehicular Activities Services (xEVAS) contract, the DGB can support the need to do suit component testing at thermal extremes and EVA operations without the cost of full suit testing. The DGB can simulate realistic delta pressures, vacuum down to 10^-5 Torr with roughing and cryogenic pumps, and a wide range of shroud temperatures achieved via a combination of Liquid Nitrogen (LN2), conditioned Gaseous Nitrogen (GN2), and Infrared (IR) lamps. Recent developmental work has verified operational status of the chamber and expanded the capabilities of the DGB to include thermal contact testing of suit gloves through the development of 2 temperature-controlled grab bars. This paper will discuss the history and capabilities of the DGB, and the chamber’s future role in the development of new spacesuit systems.

Kaixin Cui↗
NASA NTRS1975

Thermoelastic analysis of solar window of a vacuum chamber

It has been noted during space simulation test programs that the chamber penetration window becomes the limiting factor as the solar intensity increases. The temperature at the center of the window normally attains a level of 550 C, while the edge temperature remains at about 35 C. The stresses produced by this thermal gradient combined with the atmospheric pressure are studied within the framework of classical theory of elasticity. The solution for the problem is obtained by solving the static uncoupled thermoelastic equations for a circular blank, subjected to nonuniform heat on one face, by introduction of two auxiliary variables. The displacements are expressed in terms of Bessel functions and parameters of interest are computed at various mesh points of the window. The maximum principal stresses thus obtained show that even with steep temperature gradient, the safety factor is acceptable.

Amba-Rao, C. L.↗