Extended cryogenic performance of Lobar Wick heat pipe/radiator
Abstract
Two series of cryogenic-vacuum tests were performed as part of a continuing research program aimed at developing lightweight, reliable, and efficient Lobar Wick heat pipe/radiator or heat pipe/solid cryogen cooling systems for earth resource and meteorological spaceborne detectors. In the first series, a 640 cm long nitrogen heat pipe/radiator was tested from 74 to 116 K; pipe performance was isothermal to approximately 1 K. During the second, a thermal evaluation was made on the feasibility of converting a complex focal plane assembly into an integral part of a heat pipe cooling system. High power localized heating was applied along the 1.3 cm wide lip on an arc-shaped evaporator that was 42.4 cm long and 7.6 x 10.24 sq cm in cross section. Performance indicates that design goals of less than 0.5 K longitudinal and 1.0 K lateral gradients, with + or - 1 K temporal stability during transient loadings, can be achieved with power levels up to 20 watts. While no attempt was made to identify the upper heat transport limit of the Lobar Wick, 31.3 watts was successfully carried by nitrogen.
- Publication:
-
Heat Pipes
- Pub Date:
- September 1976
- Bibcode:
- 1976hepi.rept..683C
- Keywords:
-
- Cryogenics;
- Heat Pipes;
- Spacecraft Radiators;
- Wicks;
- Evaporators;
- Focal Plane Devices;
- Liquid Nitrogen;
- Remote Sensors;
- Temperature Profiles;
- Vacuum Tests;
- Fluid Mechanics and Heat Transfer