Heat balance research with a thin-walled cube in a simulated space environment

Heat balance research with a thin-balled cube was initiated to verify heat balance computer programmes of the nodal network type. The heat balance experiments were carried out in a simulated space environment (inside the NLR thermal—vacuum chamber with liquid nitrogen cooled shroud, using a carbon arc solar simulator). The experimentally...

Thermal conductivity of honeycomb sandwich panels for space applications

The thermal conductivity of a honeycomb sandwich panel was mesisured in the three characteristic directions. The measurements were carried out in the NLR space simulation chamber. The results are in good agreement with values calculated for a simplified model.

Development of a sensor for high-quality two-phase flow

The monitoring of the quality of the two-phase mixture at various locations in the system is a valuable, possibly indispensable, part of the control system needed to properly operate a two-phase heat transport system for large spacecraft. Based on a trade-off of various quality monitoring concepts, NLR started to develop a dedicated quality...

High efficiency, low pressure drop two-phase condenser: Final report

Capillary pumped two-phase systems are considered to be: -Prime candidates to provide efficient thermal management systems for future advanced spacecraft. -Promising candidates for the thermal control of advanced larger instruments (e.g. laser-based earth observation instruments) or microgravity experiments. In such capillary pumped two-phase...

High efficiency low pressure drop tow-phase condenser for space

This paper describes all analytical and experimental activities (of NLR, prime contractor, and the subcontractors Bradford Engineering and Daimler Benz Aerospace-Space Infrastructure) to develop a high efficiency low pressure drop condenser and to bring it up to pre-qualifïcation level: - The inventory, dedicated to a literature review of...

NLR contributions to Columbus Resource Module main body thermal control

This memorandum contains the original issue of the NLR contribution to ESA Columbus Resource Module Activities (Phase B2X Extended). The work has been carried out as subcontractor of Fokker Space & Systems with Dornier Systems and Aerospatiale as the element (prime) and cocontractors respectively.

Multilayer insulation blankets for spacecraft applications: thermal model accounting for outgassing and different ways of gas migration

Models describing the thermal performance of evacuated multilayer insulation blankets are usually^ based on the simple addition of the three mutually interacting modes of energy transfer: radiation between the shields, solid conduction via the components and their interfaces and gas conduction in the interstices, determined by residual gas...

Heat transfer experiments with liquid helium in Spacelab

The experiment described is proposed to be performed on the first spacelab mission. Its scientific goal is the study of heat transfer to liquid helium above and below the lambda point under nearly zero gravity conditions. Technological results to be expected, are in the field of cooling with cryogens and management of cryogens in space. The...

A theoretical investigation of gas conduction effects on multilayer insulation performance

The thermal performance of multilayer insulation hlankets depends on three (interacting) modes of energy transfer: radiation between the radiation shields, gas conduction in the residual interstitial gas and solid conduction via the contacting interfaces. The contribution of the gas conduction depends on the interstitial gas and its pressure,...

Theoretical investigation of the basic thermal performance of multilayer insulation blankets

The thermal performance of evacuated multilayer insulation blankets depends on three modes of energy transfer: radiation between the radiation shields, gas conduction m the residual interstitial gas and solid conduction via the contacting interfaces. The importance of the contributions of the three heat transfer modes depends on many parameters...

The influence of outgas on the performance of multilayer insulation blankets with perforated shields

Reported are the results of the first measurements of a series of performance experiments with nonperforated and perforated blankets. The mathematical description of the performance is considered to be in reasonable agreement with the measurements in the nonperforated case. For perforated blankets the pressure distribution inside the blanket...

Test loops for two-phase thermal management system components

Two mechanically pumped two-phase test rigs were built at NLR in order to experimentally study critical issues of spacecraft two-phase thermal management systems: - a 5 kW, 31 mm ID, freon loop, focusing on the critical components of the ESA Two-Phase Heat Transport System. - a 30000 W, 4.93 mm ID, ammonia loop, to support the development of the...

Concept of an acoustic method for particle tracking in opaque liquids

Acoustic techniques for the tracking of a tracer particle in a liquid have been detailed for a specific problem. The liquid is a molten metal in a crucible in a precision furnace; the tracer particle could be a bubble. The acoustic hardware is exterior to the furnace and is coupled to the sample via a small number of liquid-filled waveguides...