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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 19 records

Technology Development and Design of an Electrically Driven Pump Fed (EDPF) Bi-Propellant Propulsion System for a Mars Ascent Vehicle (MAV)

A Mars Ascent Vehicle (MAV), as part of a potential Mars Sample Return (MSR) campaign, is a very unique challenge and has been the focus of technology development and design efforts at JPL (Jet Propulsion Lab.) for several decades. Recent trajectory studies, for the current range of notional MAV payloads (6-25 kilograms), evaluated performance using propulsion systems in the 2.5 kiloNewton to 4.5 kiloNewton (600-1000 pounds-force) thrust range. The study examined several propulsion system approaches - solid rocket, bi-propellant and hybrid propulsion systems - and developed a ranking based on several key figures of merit. This paper focuses on the evaluations conducted for the two bi-propellant propulsion system options considered for a potential MAV. Historically, bi-propellant propulsion systems have been considered for this application; this study took a fresh look at both a conventional State of the Art (SOA) pressure fed bi-propellant propulsion system and recent developments using small EDPF (Electrically-Driven Pump-Fed) bi-propellant propulsion systems.

Vaughan, David↗

Low thrust chemical orbit to orbit propulsion system propellant management study

Low thrust chemical propulsion systems were sized for transfer of large space systems from LEO to GEO. The influence of propellant combination, tankage and insulation requirements, and propellant management techniques on the LTPS mass and volume were studied. Liquid oxygen combined with hydrogen, methane or kerosene were the propellant combinations. Thrust levels of 445, 2230, and 4450 N were combined with 1, 4 and 8 perigee burn strategies. This matrix of systems was evaluated using multilayer insulation and spray-on-foam insulation systems. Various combinations of toroidal, cylindrical with ellipsoidal domes, and ellipsoidal tank shapes were investigated. Results indicate that low thrust (445 N) and single perigee burn approaches are considerably less efficient than the higher thrust level and multiple burn strategies. A modified propellant settling approach minimized propellant residuals and decreased system complexity, in addition, the toroid/ellipsoidal tank combination was predicted to be shortest.

Dergance, R. H.↗

Low-thrust chemical orbit to orbit propulsion system propellant management study

Propellant requirements, tankage configurations, preferred propellant management techniques, propulsion systems weights, and technology deficiencies for low thrust expendable propulsion systems are examined. A computer program was utilized which provided a complete propellant inventory (including boil-off for cryogenic cases), pressurant and propellant tank dimensions for a given ullage, pressurant requirements, insulation requirements, and miscellaneous masses. The output also includes the masses of all tanks; the mass of the insulation, engines and other components; total wet system and burnout mass; system mass fraction; total impulse and burn time.

Dergance, R. H.↗

Propeller propulsion system integration: State of technology survey

A literature survey was performed to identify and review technical material applicable to the problem area of propeller propulsion system integration. The survey covered only aerodynamic interference aspects of the problem, and was restricted primarily to propeller effects on the airframe. The subject of airframe aerodynamic interference on the propeller was limited to the problem of vibration due to nonuniform inflow. The problem of airframe effects on propeller performance was not included. A total of 1121 references are given. The references are grouped into the subject areas of Aircraft Stability, Propulsive Efficiency, Aerodynamic Interference, Aerodynamic Interference-Propeller Vibration, and Miscellaneous.

Miley, S. J.↗

PC programs for the prediction of the linear stability behavior of liquid propellant propulsion systems and application to current MSFC rocket engine test programs, volume 1

Research on propulsion stability (chugging and acoustic modes), and propellant valve control was investigated. As part of the activation of the new liquid propulsion test facilities, it is necessary to analyze total propulsion system stability. To accomplish this, several codes were built to run on desktop 386 machines. These codes enable one to analyze the stability question associated with the propellant feed systems. In addition, further work was adapted to this computing environment and furnished along with other codes. This latter inclusion furnishes those interested in high frequency oscillatory combustion behavior (that does not couple to the feed system) a set of codes for study of proposed liquid rocket engines.

Doane, George B., III↗

Low-thrust chemical propulsion system propellant expulsion and thermal conditioning study. Executive summary

Preferred techniques for providing abort pressurization and engine feed system net positive suction pressure (NPSP) for low thrust chemical propulsion systems (LTPS) were determined. A representative LTPS vehicle configuration is presented. Analysis tasks include: propellant heating analysis; pressurant requirements for abort propellant dump; and comparative analysis of pressurization techniques and thermal subcoolers.

Merino, F.↗

A Survey and Evaluation of High Energy Liquid Chemical Propulsion Systems: Propellant Selection Criteria for Space Missions - Part 1

This report presents the results of a study to develop a procedure for evaluating liquid propellants in order (a) to select the most appropriate propellant (from among those under development) for each of several applications on each of the various missions in the NASA program, or (b) to select new propellants (from among those being proposed) for initiation or continuation of research and development. The analysis begins with a consideration of requirements--either for the specific application or for the various classes of applications. The known characteristics of the propellant or propellants to be evaluated are then put into a convenient form for evaluation. The next step is to determine whether or not there are requirements that simply cannot be met by the propellant. If the propellant passes this test, an optimum vehicle configuration using the propellant (and meeting all requirements) is estimated. (The configuration should be optimized with respect to the total resource consumption for all aspects of the mission, including R&D, production, logistics, and operation.) The total resource consumption for this configuration is then compared with that for similar configurations using other propellants (and meeting all requirements equally well). If all factors have been properly taken into account, this comparison of resource consumption will complete the evaluation. Such an evaluation may be performed several times, in increasing detail and with correspondingly increasing accuracy, as an R&D program proceeds, and the accuracy of the data as well as the cost of the next step in the program increase. The procedure is superior to those in common use in that it minimizes both the amount of analytical work and the number of points at which subjective value judgments are made.

LIQUID PROPELLANT↗

Development of a biowaste resistojet propulsion system propellant management and control subsystem.

The subject subsystem is under development as the major portion of an overall biowaste resistojet system development program. The design is based on the Space Station model, but incorporates features compatible with all envisioned/anticipated advancements in the interfacing environmental control life support (EC/LS) system. Results to date, for system design, development plan, component selection, and system acceptance test will be presented. Subsystem usage in functional system tests to be performed at Langley Research Center, and its application to an envisioned and integrated system, and extended manned tests, are delineated. Expanded applications of the subsystem, to control/limit external contamination of manned spacecraft, are identified.-

Greco, R. V.↗

Low-thrust chemical propulsion system propellant expulsion and thermal conditioning study

Thermal conditioning systems for satisfying engine net positive suction pressure (NPSP) requirements, and propellant expulsion systems for achieving propellant dump during a return-to-launch site (RTLS) abort were studied for LH2/LO2 and LCH4/LO2 upper stage propellant combinations. A state-of-the-art thermal conditioning system employing helium injection beneath the liquid surface shows the lowest weight penalty for LO2 and LCH4. A technology system incorporating a thermal subcooler (heat exchanger) for engine NPSP results in the lowest weight penalty for the LH2 tank. A preliminary design of two state-of-the-art and two new technology systems indicates a weight penalty difference too small to warrant development of a LH2 thermal subcooler. Analysis results showed that the LH2/LO2 propellant expulsion system is optimized for maximum dump line diameters, whereas the LCH4/LO2 system is optimized for minimum dump line diameter (LCH4) and maximum dump line diameter (LO2). The primary uncertainty is the accurate determination of two-phase flow rates through the dump system; experimentation is not recommended because this uncertainty is not considered significant.

Merino, F.↗

Propulsion stability codes for liquid propellant propulsion systems developed for use on a PC computer

Research into component modeling and system synthesis leading to the analysis of the major types of propulsion system instabilities and the characterization of various components characteristics are presented. Last year, several programs designed to run on a PC were developed for Marshall Space Flight Center. These codes covered the low, intermediate, and high frequency modes of oscillation of a liquid rocket propulsion system. No graphics were built into these programs and only simple piping layouts were supported. This year's effort was to add run time graphics to the low and intermediate frequency codes, allow new types of piping elements (accumulators, pumps, and split pipes) in the low frequency code, and develop a new code for the PC to generate Nyquist plots.

Doane, George B., III↗

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.↗

Propulsion System Options for a Potential Sample Return Lander (SRL) for Mars

A potential Mars Sample Return (MSR) campaign would be very unique challenge and has been the focus of technology development and planning efforts at JPL for several decades. The latest mission concept study focuses on a potential Sample Return Lander (SRL). The potential SRL examined several propulsion system approaches using monopropellant and bi-propellants for the terminal descent phase. A ranking was developed based on a mathematical optimization program. This paper focuses on the evaluations conducted for these system options. Historically, monopropellant and bi-propellant propulsion systems are usually considered for this application; this study took a fresh look at both conventional State of the Art (SOA) pressure fed monopropellant and bi-propellant propulsion system and augmenting the system using small Electrically Driven Pumps (EDP) for both these propulsion systems.

Preudhomme, Michael↗

Method for providing real-time control of a gaseous propellant rocket propulsion system

The new and improved methods and apparatus disclosed provide effective real-time management of a spacecraft rocket engine powered by gaseous propellants. Real-time measurements representative of the engine performance are compared with predetermined standards to selectively control the supply of propellants to the engine for optimizing its performance as well as efficiently managing the consumption of propellants. A priority system is provided for achieving effective real-time management of the propulsion system by first regulating the propellants to keep the engine operating at an efficient level and thereafter regulating the consumption ratio of the propellants. A lower priority level is provided to balance the consumption of the propellants so significant quantities of unexpended propellants will not be left over at the end of the scheduled mission of the engine.

Morris, Brian G.↗

Liquid Propulsion: Propellant Feed System Design

The propellant feed system of a liquid rocket engine determines how the propellants are delivered from the tanks to the thrust chamber. They are generally classified as either pressure fed or pump fed. The pressure-fed system is simple and relies on tank pressures to feed the propellants into the thrust chamber. This type of system is typically used for space propulsion applications and auxiliary propulsion applications requiring low system pressures and small quantities of propellants. In contrast, the pump-fed system is used for high pressure, high performance applications. The selection of one propellant feed system over another is determined based on design trade studies at both the engine and vehicle levels. This chapter first provides a brief overview of the basic configurations of pressure-fed systems. Pump-fed systems are then discussed with greater detail given to the turbomachinery design. Selected design requirements and configurations are provided.

Cannon, James L.↗