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Results for “liquid-metals”

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.

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At least 19 records

Feasibility of liquid-metal vacuum seals

A basic component of any ultrahigh-vacuum system is a seal capable of isolating a test chamber from its higher pressure surroundings. Two of the most common vacuum seals now in use are the elastomer O-ring seal and the metallic shear seal. The former has the problem of outgassing and gas permeation; the latter requires a large force per unit seal-length to maintain the sealing action. The search for a seal which would provide minimal virtual and real leak rates in a chamber, without requiring a large force to consummate the seal, led to investigation of a liquid-metal seal.

SEALANT↗

Review of experimental investigations of liquid-metal heat transfer

Experimental data of various investigators of liquid-metal heat-transfer characteristics were reevaluated using as consistent assumptions and methods as possible and then compared with each other and with theoretical results. The reevaluated data for both local fully developed and average Nusselt numbers in the turbulent flow region were found still to have considerable spread, with the bulk of the data being lower than predicted by existing analysis. An equation based on empirical grounds which represents most of the fully developed heat-transfer data is nu = 0.625 pe(0.4) where nu represents the Nusselt number and pe the Peclet number. The theoretical prediction of the heat transfer in the entrance region was found to give lower values, in most cases, than those found in the experimental work.

Lubarsky, Bernard↗

Liquid-metal technology

Liquid metal technology for high temperature heat transfer, working fluid, and electrical applications

WORKING FLUID↗

Preliminary analysis of three cycles for nuclear propulsion of aircraft

A preliminary study was made of the feasibility of three cycles for nuclear propulsion of aircraft: a direct-air-turbojet, a binary liquid-metal turbojet, and a helium compressor jet. All three cycles appeared feasible for flight at a Mach number of 0.9 and altitudes up to 50,000 feet; the liquid-metal cycle appeared feasible for flight at a Mach number of 1.5. The air and helium cycles resulted in heavier aircraft than did the liquid-metal cycle, particularly at a Mach number of 1.5. The relative advantage of the liquid-metal cycle became greater as the flight speed and altitude increased, and as the reactor wall temperature decreased.

Humble, L V↗