21 research outputs found
Thermal analysis for the Cryogenic Fluid Management Flight Experiment (CFMFE)
The purpose was to identify recent thermal analysis efforts and to review that part of the analysis that addresses the prediction of fluid and container temperature gradients during low gravity storage in space. It was concluded that both small and large tanks require hundreds of hours to reach even 60 PSIA. In about 1000 hours, the small tank is close to equilibrium; the large tank requires many thousands of hours to reach equilibrium
Analysis of Thermal-Protection Systems for Space-Vehicle Cryogenic-Propellant Tanks
Analytical techniques are presented that permit the calculation of heat-transfer rates with various thermal-protection systems for liquid-cryogenic-propellant tanks subjected to on-board, solar, and planetary heat fluxes. The thermal-protection systems considered include using closely spaced reflective surfaces (foils) and widely spaced reflective surfaces (shadow shields), insulation, arrangement of vehicle components, orientation with respect to radiant heating sources, and coatings for the control of solar absorptivity. The effectiveness of these thermal-protection systems in reducing propellant heating is shown both for ideal heat-transfer models and for a simplified hydrogen-oxygen terminal stage on a Mars mission. The proper orientation of a space-vehicle cryogenic tank with respect to the Sun is one of the more beneficial methods of reducing the heating effect of solar flux. Shadow shields can be extremely effective in reducing the propellant heating due to both solar and on-board fluxes. However, low-altitude planet orbits can result in high propellant heating rates due to planetary radiation reflected from the shields. For low-altitude orbits of more than a few days, foils appear to be desirable for all cryogenic-tank surfaces. Foils are also effective in reducing the on-board heating. A choice of shadow shields or foils cannot be made until a particular vehicle and a particular mission are chosen. The thermal conductivity of insulation materials would have to be lower by about two orders of magnitude with no increase in density before insulation could compete with reflective surfaces for use in long-duration thermal protection of cryogenic tanks in space. To demonstrate the application of the methods devised, thermal-protection systems are developed for a hydrogen-oxygen terminal stage for typical Mars missions
Altitude Investigation of Can-type Flame Holder in 20-inch-diameter Ram-jet Combustor
Altitude effects on can-type flameholder in ramjet combusto
Analysis of Thermal-Protection Systems for Space-Vehicle Cryogenic-Propellant Tanks
Analytical techniques are presented that permit the calculation of heat-transfer rates with various thermal-protection systems for liquid-cryogenic-propellant tanks subjected to on-board, solar, and planetary heat fluxes . The effectiveness of these protection systems in reducing propellant heating is shown both for ideal heat-transfer models and for a simplified hydrogen-oxygen terminal stage used for typical Mars missions
Recommended from our members
NACA Research Memorandums
Report discussing the performance of a 20-inch-diameter ram-jet engine at Mach number 3.0 over a range of simulated altitudes from 60,500 to 66,500 feet. Information about the maximum combustor efficiency, range of exhaust-nozzle total pressures, lean blow-out, diffuser total-pressure recovery, and internal thrust coefficient is provided
Recommended from our members
NACA Research Memorandums
From Introduction: "The combustor efficiency, combustor total-pressure ratio, combustor-outlet total pressure, combustor-inlet Mach number, and specific fuel consumption are presented. The effect of combustor length on efficiency and the effect of pilot operating conditions burning limits are also presented.
Recommended from our members
NACA Research Memorandums
Report presenting an investigation of the performance of a 20-inch-diameter ram-jet engine at Mach number 3.0 in a free-jet facility over a range of simulated altitudes. Results regarding the diffuser characteristics, combustor performance, thrust output, and operational characteristics are provided
Recommended from our members
NACA Research Memorandums
Report presenting an investigation conducted on a full-scale afterburner and turbojet engine to determine the effect of pressure level on afterburner-wall temperature. For a given ratio of cooling airflow to afterburner gas flow, the afterburner-wall temperature increased as afterburner-outlet pressure was increased. The results indicated that heat transfer by luminous radiation was not significant any pressure level investigated