Some chemical propulsion technology highlights
Detailed discussions of advances in the fields of turbomachinery, rocket combustion, performance, engine systems, and fluid flow components are presented.
Paul, H. G.↗
Engineering topics
Propulsion
Explore propulsion reports from NASA NTRS and DOE OSTI. Search rocket engines, electric propulsion and thrusters; verify designs and performance in the source documents.
Rocket engine bipropellant valve problems and current efforts
In developing the highly successful bipropellant valves for the Apollo primary propulsion engines, a variety of developmental problems were encountered and resolved. These problems and the new technology that is being pursued to eliminate or minimize these problems on the space shuttle orbital maneuvering engine are discussed. The space shuttle, being a reusable system, has new requirements of the valve. The potential effects of these requirements on valve design and potential solutions are also discussed.
Fries, J.↗
Liquid rocket actuators and operators
All the types of actuators and associated operators used in booster, upper stage, and spacecraft propulsion and reaction-control systems except for chemical-explosive actuators and turbine actuators are discussed. Discussion of static and dynamic seals, mechanical transmission of motion, and instrumentation is included to the extent that actuator or operator design is affected. Selection of the optimum actuator configuration is discussed for specific application which require a tradeoff study that considers all the relevant factors: available energy sources, load capacity, stroke, speed of response, leakage limitations, environmental conditions, chemical compatibility, storage life and conditions, size, weight, and cost. These factors are interrelated with overall control-system design evaluations that are beyond the scope of this monograph; however, literature references are cited for a detailed review of the general considerations. Perinent advanced-state-of-the-art design concepts are surveyed briefly.
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Composite propulsion systems for an advanced reusable launch vehicle application
Summary of a detailed engineering study conducted to evaluate the potential of composite engines when applied to the first stage of a two-stage manned advanced reusable launch vehicle. A total of 36 composite engines were evaluated for this mission/application. In all cases considered, composite engines were clearly shown to be superior when compared to an advanced liquid rocket engine. Payload in orbit results are presented for the more attractive composite engines. In addition, vehicle payload performance as a function of vehicle staging velocity is presented. Typical staging velocities are Mach 8 to 10.
Bendot, J. G.↗
Ramjet propulsion for single-stage-to-orbit vehicles
The concept of single stage earth-to-orbit transportation is studied with respect to existing and projected ramjet technology. Four types of ramjet are analyzed: fan ejector, fan ramjet, supersonic combustion ramjet, and fan ramjet with turbojet boosters. A fan ramjet with a removable fan, with separate rockets for the non-air-breathing flight phase, is considered superior to an ejector ramjet, for both ease of orbit insertion and payload boost capability. Vehicle design is also discussed in terms of trajectory integration and optimization, aerodynamic trim and stability, and complete mass estimation. Graphs are presented showing Mach number for air-breathing and non-air-breathing flight, specific impulse from various ramjet engines, and orbital-insertion parameters.
Martin, J. A.↗
Rocket exhaust plume impingement on the Voyager spacecraft
In connection with the conduction of the long-duration Voyager missions to the outer planets and the sophisticated propulsion systems required, it was necessary to carry out an investigation to avoid exhaust plume impingement problems. The rarefied gas dynamics literature indicates that, for most engineering surfaces, the assumption of diffuse reemission and complete thermal accommodation is warranted in the free molecular flow regime. This assumption was applied to an analysis of a spacecraft plume impingement problem in the near-free molecular flow regime and yielded results to within a few percent of flight data. The importance of a correct treatment of the surface temperature was also demonstrated. Specular reflection, on the other hand, was shown to yield results which may be unconservative by a factor of 2 or 3. It is pointed out that one of the most difficult portions of an exhaust plume impingement analysis is the simulation of the impinged hardware. The geometry involved must be described as accurately and completely as possible.
Baerwald, R. K.↗
Advanced oxygen-hydrocarbon Earth-to-orbit propulsion
Liquid oxygen/hydrocarbon (LO2/HC) rocket engine cycles for a surface to orbit transportation system were evaluated. A consistent engine system data base is established for defining advantages and disadvantages, system performance and operating limits, engine parametric data, and technology requirements for candidate engine systems. Preliminary comparisons of the engine cycles utilizing delivered specific impulse values are presented. Methane and propane staged combustion cycles are the highest LO2/HC performers. The hydrogen cooled LO2/methane dual throat engine was found to be the highest performing. Technology needs identified in the study include: high temperature turbines; oxidizer-rich preburners; LO2, methane, and propane cooling; methane and propane fuel-rich preburners; the HC fuel turbopump; and application of advanced composite materials to the engine system. Parametric sensitivity analysis data are displayed which show the effect of variations in engine thrust, mixture ratio, chamber pressure, area ratio, cycle life, and turbine inlet temperature on specific impulse and engine weight.
Obrien, C. J.↗
NASA Orbit Transfer Rocket Engine Technology Program
The advanced expander cycle engine with a 15,000 lb thrust level and a 6:1 mixture ratio and optimized performance was used as the baseline for a design study of the hydrogen/oxgyen propulsion system for the orbit transfer vehicle. The critical components of this engine are the thrust chamber, the turbomachinery, the extendible nozzle system, and the engine throttling system. Turbomachinery technology is examined for gears, bearing, seals, and rapid solidification rate turbopump shafts. Continuous throttling concepts are discussed. Components of the OTV engine described include the thrust chamber/nozzle assembly design, nozzles, the hydrogen regenerator, the gaseous oxygen heat exchanger, turbopumps, and the engine control valves.
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A tandem mirror plasma source for a hybrid plume plasma propulsion concept
This paper describes a tandem mirror magnetic plasma confinement device to be considered as a hot plasma source for the hybrid plume rocket concept. The hot plasma from this device is injected into an exhaust duct, which will interact with an annular layer of hypersonic neutral gas. Such a device can be used to study the dynamics of the hybrid plume and to experimentally verify the numerical predictions obtained with computer codes. The basic system design is also geared toward being lightweight and compact, as well as having high power density (i.e., several kW/sq cm) at the exhaust. This feature is aimed toward the feasibility of 'space testing'. The plasma is heated by microwaves. A 50 percent heating efficiency can be obtained by using two half-circle antennas. The preliminary Monte Carlo modeling of test particles result reported here indicates that interaction does take place in the exhaust duct. Neutrals gain energy from the ion, which confirms the hybrid plume concept.
Yang, T. F.↗
Novel extraterrestrial processing for space propulsion
In the present quantitative consideration of space processing concepts for chemicals, theoretical parametric calculations are supplemented by a bench scale experiment. Attention is given to the case of water splitting to generate hydrogen and oxygen for a simple rocket motor that can be used in periodic thrusting. This concept of in situ propellant production is treated in detail and compared with more recent energy and materials technologies.
Ramohalli, K.↗
Progress in the development of parabolized Navier-Stokes (PNS) methodology for analyzing propulsive jet mixing problems
A brief review of 2D PNS methodology is first presented which describes the specialized features of supersonic shock-capturing and subsonic pressure-split models required for the analysis of aircraft, rocket and scramjet jet mixing problems. These features include techniques for dealing with various types of embedded and interfacing subsonic regions, the inclusion of finite-rate chemistry and the direct-coupling with potential flow solutions. Preliminary 3D extensions of this PNS methodology geared to supersonic and subsonic rectangular free jet mixing problems are also reviewed. New 3D PNS work will be described which includes the development of a hybrid supersonic/subsonic free jet mixing model, and, a supersonic model geared to the analysis of turbulent mixing and combustion processes occurring in scramjet combustor/nozzle flowfields.
Dash, S. M.↗
Thrust imbalance of solid rocket motor pairs on Space Shuttle flights
This analysis extends the investigation presented at the 17th Joint Propulsion Conference in 1981 to include fifteen sets of Space Shuttle flight data. The previous report dealt only with static test data and the first flight pair. The objective is to compare the authors' previous theoretical analysis of thrust imbalance with actual Space Shuttle performance. The theoretical prediction method, which involves a Monte Carlo technique, is reviewed briefly as are salient features of the flight instrumentation system and the statistical analysis. A scheme for smoothing flight data is discussed. The effects of changes in design parameters are discussed with special emphasis on the filament wound motor case being developed to replace the steel case. Good agreement between the predictions and the flight data is demonstrated.
Foster, W. A., Jr.↗
A new high strength alloy for hydrogen fueled propulsion systems
This paper describes the development of a high-strength alloy (1241 MPa ultimate and 1103 MPa yield, with little or no degradation in hydrogen) for application in advanced hydrogen-fueled rocket engines. Various compositions of the Fe-Ni-Co-Cr system with elemental additions of Cb, Ti and Al are discussed. After processing, notched tensile specimens were tested in 34.5-MPa hydrogen at room temperature, as the main screening test. The H2/air notch tensile ratio was used as the selection/rejection criterion. The most promising alloys are discussed.
Mcpherson, W. B.↗
An experimental study of laser-supported plasmas for laser propulsion: Center director's discretionary fund project DFP-82-33
The rudiments of a rocket thruster, which receives its enthalpy from an energy source which is remotely beamed from a laser, is described. An experimental study, now partially complete, is discussed which will eventually provide a detailed understanding of the physics for assessing the feasibility of using hydrogen plasmas for accepting and converting this energy to enthalpy. A plasma ignition scheme which uses a pulsed CO2 laser was develped and the properites of the ignition spark documented, including breakdown intensities in hydrogen. A complete diagnostic system capable of determining plasma temperature and the plasma absorptivitiy for subsequent steady-state absorption of a high power CO2 laser beam are developed and demonstrative use is discussed for the preliminary case study, a two atmosphere laser supported argon plasma.
Eskridge, R. H.↗
Some aspects of space propulsion with extraterrestrial resources
Extraterrestrial resources for space processing of chemicals, in general, and propellants, in particular, are explored quantitatively. It is seen that, for several candidate space mission scenarios, space processing of both space resources and earth-carried resources can make decisive differences in the mission success for a given payload. To fix ideas and demonstrate trends, the specific case of water splitting to extract oxygen, discard (or use without storage) the resulting hydrogen, and burn earth-carried noncryogenic liquid fuel(s) in a simple rocket motor, designed for periodic thrusting, is treated in some detail. Experimental hardware is assembled and demonstrated to perform adequately, besides showing compactness of the space-packaged 'capsule' module that is self-contained. Building upon previous studies, the concept of in situ propellant production (ISPP) is reexamined in light of more recent energy and materials technologies. Missions to comets and Mars Sample Return are mentioned as candidate scenarios. The mission duration, reliability-repairability of hardware, resource availability in low earth orbit (LEO), and the thrust requirements are considered in turn. It is seen that space storage of hydrogen for extended durations (5-10 years) involves problems that require detailed studies, besides involving many presently unanswered issues. A study of the energy option in LEO and in deep space is developed in simple terms. The different solar, radioisotope, and nuclear power sources are mentioned. Storage and handling of raw and processed chemicals are considered.
Ramohalli, Kumar↗
An RF heated tandem mirror plasma propulsion study
Experimental results on a tandem mirror hybrid plume rocket involving a three-stage system of plasma injection, heating, and subsequent injection through a magnetic nozzle are presented. In the experiments, a plasma is created by breaking down the gas with electron cyclotron resonance heating at 2 kW in the central cell, and the ion species is then heated to high temperatures with ion cyclotron resonance heating at 10 kW in the end cell. A Langmuir probe measured an electron density of 2.5 x 10 to the 16th/cu m and a temperature of 100 eV in the central cell and an ion density of 1.25 x 10 to the 17th/cu m and a temperature of 500 eV in the end cell.
Yang, T. F.↗
Expendable vs reusable propulsion systems cost sensitivity
One of the key trade studies that must be considered when studying any new space transportation hardware is whether to go reusable or expendable. An analysis is presented here for such a trade relative to a proposed Liquid Rocket Booster which is being studied at MSFC. The assumptions or inputs to the trade were developed and integrated into a model that compares the Life-Cycle Costs of both a reusable LRB and an expendable LRB. Sensitivities were run by varying the input variables to see their effect on total cost. In addition a Monte-Carlo simulation was run to determine the amount of cost risk that may be involved in a decision to reuse or expend.
Hamaker, Joseph W.↗
Space Shuttle propulsion performance reconstruction from flight data
The aplication of extended Kalman filtering to estimating Space Shuttle Solid Rocket Booster (SRB) performance, specific impulse, from flight data in a post-flight processing computer program. The flight data used includes inertial platform acceleration, SRB head pressure, and ground based radar tracking data. The key feature in this application is the model used for the SRBs, which represents a reference quasi-static internal ballistics model normalized to the propellant burn depth. Dynamic states of mass overboard and propellant burn depth are included in the filter model to account for real-time deviations from the reference model used. Aerodynamic, plume, wind and main engine uncertainties are included.
Rogers, Robert M.↗