Results for “Propulsion System” — Page 44

NASA NTRS1980

Energy efficient engine: Flight propulsion system preliminary analysis and design

The characteristics of an advanced flight propulsion system (FPS), suitable for introduction in the late 1980's to early 1990's, was more fully defined. It was determined that all goals for efficiency, environmental considerations, and economics could be met or exceeded with the possible exception of NOx emission. In evaluating the FPS, all aspects were considered including component design, performance, weight, initial cost, maintenance cost, engine system integration (including nacelle), and aircraft integration considerations. The current FPS installed specific fuel consumption was reduced 14.2% from that of the CF6-50C reference engine. When integrated into an advanced, subsonic, study transport, the FPS produced a fuel burn savings of 15 to 23% and a direct operating cost reduction of 5 to 12% depending on the mission and study aircraft characteristics relative to the reference engine.

Johnston, R. P.↗

NASA NTRS1979

Energy efficient engine. Flight propulsion system preliminary analysis and design

The characteristics of an advanced Flight Propulsion System (FPS) suitable for introduction in the late 1980's to early 1990's, were defined. It was determined that NASA goals for efficiency, environmental considerations, and economics could be met or exceeded with the possible exception of NOx emission. In evaluating the FPS, all aspects were considered including component design, performance, weight, initial cost, maintenance cost, engine-system integration (including nacelle), and aircraft integration considerations. In terms of the NASA goals, the current FPS installed specific fuel consumption was reduced 14.2% from that of the CF6-50C reference engine. When integrated into an advanced, subsonic, study transport, the FPS produced a fuel-burn savings of 15 to 23% and a direct operating cost reduction of 5 to 12% depending on the mission and study-aircraft characteristics relative to the reference engine.

Johnston, R. P.↗

NASA NTRS1986

Space station propulsion technology: Space station propulsion system test bed test plan

Testing of the hydrogen/oxygen Space Station Propulsion System will demonstrate the technology readiness for the IOC application. To facilitate early demonstration of this technology and to allow demonstration of maturing technology, this testing will be performed with the components installed on a test bed which simulated the Space Station Structure. The test plan contains a description of the test bed, test objective, instrumentation plan, and controls plan. Each of these is discussed in detail.

Briley, G. L.↗

NASA NTRS1989

Average-passage simulation of counter-rotating propfan propulsion systems as applied to cruise missiles

Counter-rotating propfan (CRP) propulsion technologies are currently being evaluated as cruise missile propulsion systems. The aerodynamic integration concerns associated with this application are being addressed through the computational modeling of the missile body-propfan flowfield interactions. The work described in this paper consists of a detailed analysis of the aerodynamic interactions between the control surfaces and the propfan blades through the solution of the average-passage equation system. Two baseline configurations were studied, the control fins mounted forward of the counter-rotating propeller and the control fins mounted aft of the counter-rotating propeller. In both cases, control fin-propfan separation distance and control fin deflection angle were varied.

Mulac, Richard A.↗

NASA NTRS1989

Average-passage simulation of counter-rotating propfan propulsion systems as applied to cruise missiles

Counter-rotating propfan (CRP) propulsion technologies are currently being evaluated as cruise missile propulsion systems. The aerodynamic integration concerns associated with this application are being addressed through the computational modeling of the missile body-propfan flowfield interactions. The work described in this paper consists of a detailed analysis of the aerodynamic interactions between the control surfaces and the propfan blades through the solution of the average-passage equation system. Two baseline configurations were studied, the control fins mounted forward of the counter-rotating propeller and the control fins mounted aft of the counter-rotating propeller. In both cases, control fin-propfan separation distance and control fin deflection angle were varied.

Mulac, Richard A.↗

NASA NTRS1991

Comments on dual-mode nuclear space power and propulsion system concepts

Some form of Dual-Mode Nuclear Space Power & Propulsion System (D-MNSP&PS) will be essential to spacefaring throughout teh solar system and that such systems must evolve as mankind moves into outer space. The initial D-MNPSP&PS Reference System should be based on (1) present (1990), and (2) advanced (1995) technology for use on comparable mission in the 2000 and 2005 time period respectively. D-MNSP&PS can be broken down into a number of subsystems: Nuclear subsystems including the energy source and controls for the release of thermal power at elevated temperatures; power conversion subsystems; waste heat rejection subsystems; and control and safety subsystems. These systems are briefly detailed.

Layton, J. Preston↗

NASA NTRS1991

Slosh wave excitation due to cryogenic liquid reorientation in space-based propulsion system

The objective of the cryogenic fluid management of the spacecraft propulsion system is to develop the technology necessary for acquistion or positioning of liquid and vapor within a tank in reduced gravity to enable liquid outflow or vapor venting. In this study slosh wave excitation induced by the resettling flow field activated by 1.0 Hz medium frequency impulsive reverse gravity acceleration during the course of liquid fluid reorientation with the initiation of geyser for liquid filled levels of 30, 50, and 80 percent have been studied. Characteristics of slosh waves with various frequencies excited are discussed.

Hung, R. J.↗

NASA NTRS1995

F-15 propulsion system

A brief description of the NASA F-15 research aircraft propulsion system is given. The F-15 is powered by two PW1128 afterburning turbofan engines which are growth versions of the F100-PW-100 engine. The PW1128 is controlled by a full-authority digital electronic engine control (DEEC). The F-15 inlet is a two-dimensional, three-ramp, external compression design with partially cut back side plates. Each inlet is independently controlled by an electronic air inlet controller (EAIC).

Bushman, Mark↗

NASA NTRS2006

Marshall Space Flight Center Propulsion Systems Department (PSD) KM Initiative

NASA Marshall Space Flight Center s Propulsion Systems Department (PSD) is four months into a fifteen month Knowledge Management (KM) initiative to support enhanced engineering decision making and analyses, faster resolution of anomalies (near-term) and effective, efficient knowledge infused engineering processes, reduced knowledge attrition, and reduced anomaly occurrences (long-term). The near-term objective of this initiative is developing a KM Pilot project, within the context of a 3-5 year KM strategy, to introduce and evaluate the use of KM within PSD. An internal NASA/MSFC PSD KM team was established early in project formulation to maintain a practitioner, user-centric focus throughout the conceptual development, planning and deployment of KM technologies and capabilities with in the PSD. The PSD internal team is supported by the University of Alabama's Aging Infrastructure Systems Center Of Excellence (AISCE), Intergraph Corporation, and The Knowledge Institute. The principle product of the initial four month effort has been strategic planning of PSD KM implementation by first determining the "as is" state of KM capabilities and developing, planning and documenting the roadmap to achieve the desired "to be" state. Activities undertaken to support the planning phase have included data gathering; cultural surveys, group work-sessions, interviews, documentation review, and independent research. Assessments and analyses have been performed including industry benchmarking, related local and Agency initiatives, specific tools and techniques used and strategies for leveraging existing resources, people and technology to achieve common KM goals. Key findings captured in the PSD KM Strategic Plan include the system vision, purpose, stakeholders, prioritized strategic objectives mapped to the top ten practitioner needs and analysis of current resource usage. Opportunities identified from research, analyses, cultural/KM surveys and practitioner interviews include: executive and senior management sponsorship, KM awareness, promotion and training, cultural change management, process improvement, leveraging existing resources and new innovative technologies to align with other NASA KM initiatives (convergence: the big picture). To enable results based incremental implementation and future growth of the KM initiative, key performance measures have been identified including stakeholder value, system utility, learning and growth (knowledge capture, sharing, reduced anomaly recurrence), cultural change, process improvement and return-on-investment. The next steps for the initial implementation spiral (focused on SSME Turbomachinery) have been identified, largely based on the organization and compilation of summary level engineering process models, data capture matrices, functional models and conceptual-level systems architecture. Key elements include detailed KM requirements definition, KM technology architecture assessment, evaluation and selection, deployable KM Pilot design, development, implementation and evaluation, and justifying full implementation (estimated Return-on-Investment). Features identified for the notional system architecture include the knowledge presentation layer (and its components), knowledge network layer (and its components), knowledge storage layer (and its components), User Interface and capabilities. This paper provides a snapshot of the progress to date, the near term planning for deploying the KM pilot project and a forward look at results based growth of KM capabilities with-in the MSFC PSD.

Caraccioli, Paul↗

NASA NTRS2008

Simulink Model of the Ares I Upper Stage Main Propulsion System

A numerical model of the Ares I upper stage main propulsion system is formulated based on first principles. Equation's are written as non-linear ordinary differential equations. The GASP fortran code is used to compute thermophysical properties of the working fluids. Complicated algebraic constraints are numerically solved. The model is implemented in Simulink and provides a rudimentary simulation of the time history of important pressures and temperatures during re-pressurization, boost and upper stage firing. The model is validated against an existing reliable code, and typical results are shown.

Burchett, Bradley T.↗

NASA NTRS2015

NASA Glenn Propulsion Systems Lab (PSL) Icing Facility Update

The NASA Glenn Research Center Propulsion Systems Lab (PSL) was recently upgraded to perform engine inlet ice crystal testing in an altitude environment. The system installed 10 spray bars in the inlet plenum for ice crystal generation using 222 spray nozzles. As an altitude test chamber, PSL is capable of simulation of in-flight icing events in a ground test facility. The system was designed to operate at altitudes from 4,000 ft. to 40,000 ft. at Mach numbers up to 0.8M and inlet total temperatures from -60F to +15F.

Calibrating↗

NASA NTRS2016

Update on the NASA Glenn Propulsion Systems Lab Ice Crystal Cloud Characterization (2015, 2016)

NASA Glenn's Propulsion Systems Lab, an altitude engine test facility, was outfitted with a spray system to generate ice crystals in 2011. Turbine engines and driven rigs can experience ice crystal icing at flight altitudes, temperatures and Mach numbers. To support these tests, four ice crystal characterizations have been conducted in two different facility configurations. In addition, super-cooled liquid and mixed phase clouds have also been generated. This paper represents a work in progress. It will describe some of the 11-parameter calibration space, and how those parameters interact with each other, the instrumentation used to characterize the cloud and present a sample of the cloud characterization results.

Engine Icing↗

NASA NTRS1966

Development of compressor end seals stator interstage seals, and stator pivot seals in air breathing propulsion systems Semiannual report no. 1, 29 Jun. - 31 Dec. 1965

Seal concepts evaluation for compressor end seals, stator interchange seals, and stator pivot seals in air breathing propulsion system

SEALING↗

NASA NTRS2015

Service Life Extension of the ISS Propulsion System Elements

The International Space Station (ISS) is a result of international collaboration in building a sophisticated laboratory of an unprecedented scale in Low Earth Orbit. After a complex assembly sequence spanning over a decade, some of the early modules launched at the beginning of the program would reach the end of their certified lives, while the newer modules were just being commissioned into operation. To maximize the return on global investments in this one-of-a-kind orbiting platform that was initially conceived for a service life until 2016, it is essential for the cutting edge research on ISS to continue as long as the station can be sustained safely in orbit. ISS Program is assessing individual modules in detail to extend the service life of the ISS to 2024, and possibly to 2028. Without life extension, Functional Cargo Block (known by its Russian acronym as FGB) and the Service Module (SM), two of the early modules on the Russian Segment, would reach the end of their certified lives in 2013 and 2015 respectively. Both FGB and SM are critical for the propulsive function of the ISS. This paper describes the approach used for the service life extension of the FGB propulsion system. Also presented is an overview of the system description along with the process adopted for developing the life test plans based on considerations of system failure modes, fault tolerance and safety provisions. Tests and analyses performed, important findings and life estimates are summarized. Based on the life extension data, FGB propulsion system, in general, is considered ready for a service life until 2028.

Kamath, Ulhas↗

NASA NTRS1992

Highlights of NASA's Special ETO Program Planning Workshop on rocket-based combined-cycle propulsion system technologies

A NASA workshop on rocket-based combined-cycle propulsion technologies is described emphasizing the development of a starting point for earth-to-orbit (ETO) rocket technologies. The tutorial is designed with attention given to the combined development of aeronautical airbreathing propulsion and space rocket propulsion. The format, agenda, and group deliberations for the tutorial are described, and group deliberations include: (1) mission and space transportation infrastructure; (2) vehicle-integrated propulsion systems; (3) development operations, facilities, and human resource needs; and (4) spaceflight fleet applications and operations. Although incomplete the workshop elevates the subject of combined-cycle hypersonic propulsion and develops a common set of priniciples regarding the development of these technologies.

Escher, W. J. D.↗

NASA NTRSDate not supplied

Failure Behavior and Control Based Mitigation for a Parallel Hybrid Propulsion System

NASA is pursuing research to advance Electrified Aircraft Propulsion (EAP) technologies that address fuel burn and emission reduction goals. EAP brings the potential for improved performance over the state of the art. However, for these systems to be practical and certifiable, they need to possess adequate robustness to adverse conditions including a variety of system failures that are not applicable to conventional turbofans today. Numerous EAP concepts interface gas turbine engines with an electrical power system that includes electric machines and sometimes electrical energy storage. The expansion of the powertrain increases the probability of encountering a failure and introduces new failure modes. Failures within the electrical power system may also impact the gas turbine engine(s) to which the electrical powertrain is coupled. This effort investigates failures originating in the electrical power system and their impact on the parallel hybrid propulsion system. Reversionary control strategies are also demonstrated to reduce the impact of the failures. Failure mitigation strategies were devised and employed in simulation. Various failure scenarios were simulated including those occurring during steady state operation, transients, and takeoff and landing scenarios. The timing of the failure and delay in failure identification and activation of mitigation strategies are noteworthy variables in the study. While the system remained stable throughout all failure scenarios, delays in failure identification could result in undesirable conditions such as increased operating temperatures and reduced stall margin. The results demonstrate successful mitigation of failures through reversionary control modes and help to generate confidence in the robustness of the conceptual parallel hybrid propulsion system.

Failure behavior↗

NASA NTRSDate not supplied

Failure Behavior and Control-Based Mitigation for a Parallel Hybrid Propulsion System

NASA is pursuing research to advance Electrified Aircraft Propulsion (EAP) technologies that address fuel burn and emission reduction goals. EAP brings the potential for improved performance over the state of the art. However, for these systems to be practical and certifiable, they need to possess adequate robustness to adverse conditions including a variety of system failures that are not applicable to conventional turbofans today. Numerous EAP concepts interface gas turbine engines with an electrical power system that includes electric machines and sometimes electrical energy storage. The expansion of the powertrain increases the probability of encountering a failure and introduces new failure modes. Failures within the electrical power system may also impact the gas turbine engine(s) to which the electrical powertrain is coupled. This effort investigates failures originating in the electrical power system and their impact on the parallel hybrid propulsion system. Reversionary control strategies are also demonstrated to reduce the impact of the failures. Failure mitigation strategies were devised and employed in simulation. Various failure scenarios were simulated including those occurring during steady state operation, transients, and takeoff and landing scenarios. The timing of the failure and delay in failure identification and activation of mitigation strategies are noteworthy variables in the study. While the system remained stable throughout all failure scenarios, delays in failure identification could result in undesirable conditions such as increased operating temperatures and reduced stall margin. The results demonstrate successful mitigation of failures through reversionary control modes and help to generate confidence in the robustness of the conceptual parallel hybrid propulsion system.

Failure behavior↗

NASA NTRSDate not supplied

Considering Turbofan Operability in Hybrid Electric Aircraft Propulsion System Design

This paper explores the design of a hybrid electric aircraft propulsion system that uses a turbofan to power an electric system. In such a system, the gas turbine will experience a loss of power generation as altitude increases, however the electric system will not. This difference results in designs that may over size the electric system at high altitude or under size at low altitude. Two studies are performed within this paper. The first looks at extracting power from the engine for use with electric aircraft propulsion at cruise and the second reviews a design of an engine that uses thrust assist for takeoff. Both studies look at the effects of changing altitude on the amount of power extraction or insertion that can be taken from the turbofan as dictated by operability limits. Results of the paper show that low-pressure compressor surge margin and high-pressure compressor speed can be pushed to unaccepted limits with large scale power extraction or insertion, however these issues can be mitigated by adding power extraction or insertion at off design operating points to compensate. Additionally, the benefits of thrust assist are quantified for this configuration demonstrating a reduction in thrust specific fuel consumption at cruise of over 5%.

Gas Turbine↗