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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 1,225 records · Page 68

All sources NASA NTRS DOE OSTI

NASA NTRS1971

Experimental investigation to simulate propellant heating in the nuclear light bulb engine.

Experiments to heat a simulated propellant to high bulk temperatures by the absorption of thermal radiation are discussed. Argon seeded with micron-sized carbon particles was used as the simulated propellant; a 500 kw d-c arc was used as the radiant energy source. Bulk temperatures up to 3860 K were obtained with greater than 95% of the incident radiation absorbed. The arc radiation source, seed dispersal equipment, techniques used to prevent transparent wall coating by the seeds, and calorimetric measurement of bulk temperature are also discussed.

Klein, J. F.↗

NASA NTRS1971

Maximum propellant utilization in an electron-bombardment thruster.

Current theory and experimental data on propellant utilization in electron-bombardment ion thrusters are reviewed. Because the majority of investigations have been conducted with mercury, the presentation emphasizes that propellant. The results are presented in as general a form as possible to facilitate use in areas other than space propulsion.

Kaufman, H. R.↗

NASA NTRS1972

Coupling between structure and liquid propellants in a parallel-stage space shuttle design.

A study was conducted to determine the influence of liquid propellants on the dynamic loads for space shuttle vehicles. A parallel-stage configuration model was designed and tested to determine the influence of liquid propellants on coupled natural modes. A forty degree-of-freedom analytical model was also developed for predicting these modes. Currently available analytical models were used to represent the liquid contributions, even though coupled longitudinal and lateral motions are present in such a complex structure. Agreement between the results was found in the lower few modes.

Kana, D. D.↗

NASA NTRS1972

Oscillatory burning of solid propellants including gas phase time lag.

An analysis has been performed for oscillatory burning of solid propellants including gas phase time lag. The gaseous flame is assumed to be premixed and laminar with a one-step overall chemical reaction. The propellant is assumed to decompose according to the Arrenhius Law, with no condensed phase reaction. With this model, strong gas phase resonance has been found in certain cases at the characteristic gas-phase frequencies, but the peaking of the acoustic admittance is in the direction favoring the damping of pressure waves. At still higher frequencies, moderate wave-amplifying ability was found. The limit of low frequency response obtained previously by Denison and Baum was recovered, and the limitations of the quasi-steady theory were investigated.

T'Ien, J. S.↗

NASA NTRS1972

Orbital propellant depot system.

Review of some of the problems involved in the design of a long-term propellant storage depot in earth orbit to act as a resupply station for cargo/personnel shuttles between earth orbit and lunar orbit, between low earth orbit and synchronous orbit, and possibly for use with interplanetary probes. The problems discussed pertain essentially to the long-term storage and propellant transfer capabilities.

Wilson, D. J.↗

NASA NTRS1972

Some considerations in the combustion of AP/composite propellants

Theoretical studies are presented on the time-independent and oscillatory combustion of nonmetallized AP/composite propellants. Three hypotheses are introduced: (1) The extent of propellant degradation at the vaporization step has to be specified through a scientific criterion. (2) The condensed phase degradation reaction of ammonium perchlorate to a vaporizable state is the overall rate-limiting step. (3) Gas phase combustion rate is controlled by the mixing rate of fuel and oxidizer vapors. In the treatment of oscillatory combustion, the assumption of quasi-steady fluctuations in the gas phase is used to supplement these hypotheses. In comparison with experimental data, this study predicts several of the observations including a few that remain inconsistent with theoretical results.

Kumar, R. N.↗

NASA NTRS1971

Orbiting propellant depot safety. Volume 3: Appendices

Appendices to support the findings of the Orbiting Propellant Depot Safety study are presented. The subjects discussed are ullage control subsystems, evaluation of methods, propellant transfer, and baseline subsystem selection.

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NASA NTRS1972

Pulse performance analysis for small hypergolic propellant rocket engines

Small rocket engine tests were conducted for the purpose of obtaining pulse performance data to aid in preliminary design and evaluation of attitude control systems. Both monopropellant and hypergolic bipropellant engines of thrust levels from 5 to 445 N (1 to 100 lb) were tested. The performance data for the hypergolic propellant rockets are compared with theoretical performance calculated from idealized chamber filling and evacuation characteristics. Electromechanical delays in valve response and heat transfer characteristics were found to cause substantial deviation between theoretical performance and test performance. The theoretical analysis is modified to obtain a semiempirical model for hypergolic propellant rockets.

Smith, G. W.↗

NASA NTRS1971

Orbiting propellent depot safety. Volume 2: Technical discussion

The results of a study assessing the gross requirements and concomitant safety hazards associated with the operation of several configurations of orbiting propellant depots (OPD) are presented. The major structural and operational aspects of the integral, semimodular, and modular concepts are described. The concepts are evaluated to determine their safety hazards, and emphasis is placed on propellant transfer to and from the OPD. The study indicates that a modular mode of depot resupply is desirable regardless of the OPD configuration. This resupply mode requires no flow transfer to resupply either the semimodular or modular OPD. Of the three concepts, the semimodular appears to provide the best operational advantage and lowest safety risk.

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NASA NTRS1972

Advanced techniques for determining long term compatibility of materials with propellants

The search for advanced measurement techniques for determining long term compatibility of materials with propellants was conducted in several parts. A comprehensive survey of the existing measurement and testing technology for determining material-propellant interactions was performed. Selections were made from those existing techniques which were determined could meet or be made to meet the requirements. Areas of refinement or changes were recommended for improvement of others. Investigations were also performed to determine the feasibility and advantages of developing and using new techniques to achieve significant improvements over existing ones. The most interesting demonstration was that of the new technique, the volatile metal chelate analysis. Rivaling the neutron activation analysis in terms of sensitivity and specificity, the volatile metal chelate technique was fully demonstrated.

Green, R. L.↗

NASA NTRS1973

Investigation of gaseous propellant combustion and associated injector/chamber design guidelines

Injector design criteria are provided for gaseous hydrogen-gaseous oxygen propellants. Design equations and procedures are presented which will allow an injector-chamber designer to a priori estimate of the performance, compatibility and stability characteristics of prototype injectors. The effects of chamber length, element geometry, thrust per element, mixture ratio, impingement angle, and element spacing were evaluated for four element concepts and their derivatives. The data from this series of tests were reduced to a single valued mixing function that describes the mixing potential of the various elements. Performance, heat transfer and stability data were generated for various mixture ratios, propellant temperatures, chamber pressures, contraction ratios, and chamber lengths. Applications of the models resulted in the design of procedures, whereby the performance and chamber heat flux can be calculated directly, and the injector stability estimated in conjunction with existing models.

Calhoon, D. F.↗

NASA NTRS1973

Regeneratively cooled rocket engine for space storable propellants

Analyses and experimental studies were performed with the OF2 (F2/O2)/B2H6 propellant combination over a range in operating conditions to determine suitability for a space storable pressure fed engine configuration for an extended flight space vehicle configuration. The regenerative cooling mode selected for the thrust chamber was explored in detail with the use of both the fuel and oxidizer as coolants in an advanced milled channel construction thrust chamber design operating at 100 psia chamber pressure and a nominal mixture ratio of 3.0 with a 60:1 area ratio nozzle. Benefits of the simultaneous cooling as related to gaseous injection of both fuel and oxidizer propellants were defined. Heat transfer rates, performance and combustor stability were developed for impinging element triplet injectors in uncooled copper calorimeter hardware with flow, pressure and temperature instrumentation. Evaluation of the capabilities of the B2H6 and OF2 during analytical studies and numerous tests with flow through electrically heated blocks provided design criteria for subsequent regenerative chamber design and fabrication.

Wagner, W. R.↗

NASA NTRS1973

Centaur D-1T propulsion and propellant systems

A description is presented of the propulsion and propellant systems of the Centaur D-1T, an improved version of the Centaur high energy upper state. The primary change to the propulsion system to provide three-burn capability was the addition of radiation shielding to the propellant duct. The redundant valves and feed paths were added to the H202 supply and reaction control system to increase system tolerance to the most probable causes of failure. Other changes were made to enhance mission capability of the Centaur, and represent an increase in inherent reliability of the vehicle through reduction of single failure points and by substitution of more reliable components.

Goette, W. E.↗

NASA NTRS1972

Optimum performance of static propellers and rotors.

A criterion for the optimum performance of static propellers and hovering helicopter rotors is developed. Numerical results are presented for the optimum radial distributions of circulation and inflow at the propeller disk and relating the optimum power coefficient and the figure of merit to the thrust coefficient. It is shown that the present theory, which fully accounts for the effect of slipstream rotation, predicts optimum distributions of circulation and inflow that differ significantly from those based on approximate methods.

Wu, J. C.↗

NASA NTRS1972

Extending the life and recycle capability of earth storable propellant systems.

Rocket propulsion systems for reusable vehicles will be required to operate reliably for a large number of missions with a minimum of maintenance and a fast turnaround. For the space shuttle reaction control system to meet these requirements, current and prior related system failures were examined for their impact on reuse and, where warranted, component design and/or system configuration changes were defined for improving system service life. It was found necessary to change the pressurization component arrangement used on many single-use applications in order to eliminate a prevalent check valve failure mode and to incorporate redundant expulsion capability in propellant tank designs to achieve the necessary system reliability. Material flaws in pressurant and propellant tanks were noted to have a significant effect on tank cycle life. Finally, maintenance considerations dictated a modularized systems approach, allowing the system to be removed from the vehicle for service and repair at a remote site.

Schweickert, T. F.↗

NASA NTRS1972

Critical mass of cryogenic rocket propellants.

This paper introduces the new concept of 'Critical mass' for liquid rocket propellants and verifies its existence. Internal mechanisms inherent in the mixing processes of fuel and oxidizer produce ignition conditions and centers which limit the quantities which can be brought together without explosion, or limit the size of the explosion which can be produced, regardless of the total propellant quantities present.

Farber, E. A.↗

NASA NTRS1974

Propellant acquisition device for use with a spinning toroidal tank

System consists of four radially disposed communication channels attached to propellant-retaining ring situated at bottom of toroidal tank. Ring-and-channel acquisition system design provides uniform propellant distribution within spinning tank during all mission phases.

Anderson, J. E.↗

NASA NTRS1973

Space shuttle seal material and design development for earth storable propellant systems

The results of a program to investigate and characterize seal materials suitable for space shuttle storable propellant systems are given. Two new elastomeric materials were identified as being potentially superior to existing state-of-the art materials for specific sealing applications. These materials were AF-E-124D and AF-E-411. AF-E-124D is a cured perfluorinated polymer suitable for use with dinitrogen tetroxide oxidizer, and hydrazine base fuels. AF-E-411 is an ethylene propylene terpolymer material for hydrazine base fuel service. Data are presented relative to low and high temperature characteristics as well as propellant exposure effects. Types of data included are: mechanical properties, stress strain curves, friction and wear characteristics, compression set and permeability. Sealing tests with a flat poppet-seal valve were conducted for verification of sealing capability. A bibliography includes over 200 references relating to seal design or materials and presents a concise tabulation of the more useful seal design data sources.

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