Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “START Program”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,459 records · Page 81
All sourcesNASA NTRSDOE OSTI
NASA NTRS2010

Testing to Transition the J-2X from Paper to Hardware

The J-2X Upper Stage Engine (USE) will be the first new human-rated upper stage engine since the Apollo program of the 1960s. It is designed to carry the Ares I and Ares V into orbit and send the Ares V to the Moon as part of NASA's Constellation Program. This paper will provide an overview of progress on the design, testing, and manufacturing of this new engine in 2009 and 2010. The J-2X embodies the program goals of basing the design on proven technology and experience and seeking commonality between the Ares vehicles as a way to minimize risk, shorten development times, and live within current budget constraints. It is based on the proven J-2 engine used on the Saturn IB and Saturn V launch vehicles. The prime contractor for the J-2X is Pratt & Whitney Rocketdyne (PWR), which is under a design, development, test, and engineering (DDT&E) contract covering the period from June 2006 through September 2014. For Ares I, the J-2X will provide engine start at approximately 190,000 feet, operate roughly 500 seconds, and shut down. For Ares V, the J-2X will start at roughly 190,000 feet to place the Earth departure stage (EDS) in orbit, shut down and loiter for up to five days, re-start on command and operate for roughly 300 seconds at its secondary power level to perform trans lunar injection (TLI), followed by final engine shutdown. The J-2X development effort focuses on four key areas: early risk mitigation, design risk mitigation, component and subassembly testing, and engine system testing. Following that plan, the J-2X successfully completed its critical design review (CDR) in 2008, and it has made significant progress in 2009 and 2010 in moving from the drawing board to the machine shop and test stand. Post-CDR manufacturing is well under way, including PWR in-house and vendor hardware. In addition, a wide range of component and sub-component tests have been completed, and more component tests are planned. Testing includes heritage powerpack, turbopump inducer water flow, turbine air flow, turbopump seal testing, main injector and gas generator, injector testing, augmented spark igniter testing, nozzle side loads cold flow testing, nozzle extension film cooling flow testing, control system testing with hardware in the loop, and nozzle extension emissivity coating tests. In parallel with hardware manufacturing, work is progressing on the new A-3 test stand to support full duration altitude testing. The Stennis A-2 test stand is scheduled to be turned over to the Constellation Program in September 2010 to be modified for J-2X testing also. As the structural steel was rising on the A-3 stand, work was under way in the nearby E complex on the chemical steam generator and subscale diffuser concepts to be used to evacuate the A-3 test cell and simulate altitude conditions.

Byrd, Tom↗
DOE OSTI2020

Improving the Success of Underrepresented Populations in Computer and Computational Science Research with the CRA-W Women and URMD Grad Cohort Workshops

The Computing Research Association’s Committee on Widening Participation (CRA-WP) aims to increase the number of individual researchers from underrepresented groups in computing (UGC) (including women, underrepresented minorities, and persons with disabilities) who participate and succeed in computer science research at every stage of the research pipeline. Achieving these objectives requires that an increasing number of individuals from UGC start and progress to the next stage. The CRA-WP Grad Cohort Workshops are focused at the graduate level to maximize the likelihood participants will successfully complete their graduate degrees. Factors such as role models, skills, competence, confidence, mentoring, social support, and development of identity as a researcher help students to persist in graduate school, while factors such as sexism, racism, and dissatisfaction with their graduate program may cause them to leave. We, therefore, help first, second, and third year students build their skills, research strategies, and confidence; meet potential mentors from outside their institutions; develop connections with each other and with their research communities; and inform them about strategies for successful publishing, speaking, and advisor management strategies. By targeting early graduate students, we seek to help them stay in graduate school and in research.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗
DOE OSTI2022

Spark-Assisted HCCI Residential CHP

A transformative small spark ignition (SI) internal combustion (IC) engine fueled with natural gas was developed for combined heat and power (CHP) applications using a combination of cycle simulations, computational fluid dynamics (CFD) modeling, and engine experiments. The resulting 1 kW CHP engine was demonstrated to achieve 36.1% brake thermal efficiency (BTE) while meeting aggressive exhaust emissions targets using a low-cost three-way catalyst. Starting from a “clean-sheet” design, modeling tools were used to select the optimal engine parameters and operating characteristics. The disruptive technologies developed for the CHP system have a target lifetime of at least 10 years. The engine cost at volume of 10,000 units was estimated to be $\$$1,050. A combination of experimental and simulation results were used to identify a path to the program target of 38.6% BTE. Base engine design parameters (i.e., displacement, speed, bore, stroke, valve timings, and compression ratio) were optimized to reduce friction, heat transfer, and exhaust losses. The base clean sheet prototype engine achieved 32% BTE. Optimization of the lube oil and coolant temperatures added 1.8% BTE. The addition of exhaust gas recirculation added 1.1% BTE. Novel thermal barrier coatings (TBCs) developed over the course of the project added 1.2% BTE. Further improvements in engine friction reduction (1.3% BTE) and improved combustion (1.2% BTE) are estimated to meet the program target 38.6% BTE, while also meeting the stringent criteria pollutant emissions targets.

42 ENGINEERING↗
NASA NTRS1978

Alternatives for jet engine control

General goals of the research were classified into two categories. The first category involves the use of modern multivariable frequency domain methods for control of engine models in the neighborhood of a quiescent point. The second category involves the use of nonlinear modelling and optimization techniques for control of engine models over a more extensive part of the flight envelope. In the frequency domain category, works were published in the areas of low-interaction design, polynomial design, and multiple setpoint studies. A number of these ideas progressed to the point at which they are starting to attract practical interest. In the nonlinear category, advances were made both in engine modelling and in the details associated with software for determination of time optimal controls. Nonlinear models for a two spool turbofan engine were expanded and refined; and a promising new approach to automatic model generation was placed under study. A two time scale scheme was developed to do two-dimensional dynamic programming, and an outward spiral sweep technique has greatly speeded convergence times in time optimal calculations.

Leake, R. J.↗
NASA NTRS1999

Research Data Acquired in World-Class, 60-atm Subsonic Combustion Rig

NASA Lewis Research Center's new, world-class, 60-atmosphere (atm) combustor research facility, the Advanced Subsonic Combustion Rig (ASCR), is in operation and producing highly unique research data. Specifically, data were acquired at high pressures and temperatures representative of future subsonic engines from a fundamental flametube configuration with an advanced fuel injector. The data acquired include exhaust emissions as well as pressure and temperature distributions. Results to date represent an improved understanding of nitrous oxide (NOx) formation at high pressures and temperatures and include an NOx emissions reduction greater than 70 percent with an advanced fuel injector at operating pressures to 800 pounds per square inch absolute (psia). ASCR research is an integral part of the Advanced Subsonic Technology (AST) Propulsion Program. This program is developing critical low-emission combustion technology that will result in the next generation of gas turbine engines producing 50 to 70 percent less NOx emissions in comparison to 1996 International Civil Aviation Organization (ICAO) limits. The results to date indicate that the AST low-emission combustor goals of reducing NOx emissions by 50 to 70 percent are feasible. U.S. gas turbine manufacturers have started testing the low-emissions combustors at the ASCR. This collaborative testing will enable the industry to develop low-emission combustors at the high pressure and temperature conditions of future subsonic engines. The first stage of the flametube testing has been implemented. Four GE Aircraft Engines low-emissions fuel injector concepts, three Pratt & Whitney concepts, and two Allison concepts have been tested at Lewis ASCR facility. Subsequently, the flametube was removed from the test stand, and the sector combustor was installed. The testing of low emissions sector has begun. Low-emission combustors developed as a result of ASCR research will enable U.S. engine manufacturers to compete on a worldwide basis by producing environmentally acceptable commercial engines.

Lee, Chi-Ming↗
NASA NTRS2013

Developing IVHM Requirements for Aerospace Systems

The term Integrated Vehicle Health Management (IVHM) describes a set of capabilities that enable sustainable and safe operation of components and subsystems within aerospace platforms. However, very little guidance exists for the systems engineering aspects of design with IVHM in mind. It is probably because of this that designers have to use knowledge picked up exclusively by experience rather than by established process. This motivated a group of leading IVHM practitioners within the aerospace industry under the aegis of SAE's HM-1 technical committee to author a document that hopes to give working engineers and program managers clear guidance on all the elements of IVHM that they need to consider before designing a system. This proposed recommended practice (ARP6883 [1]) will describe all the steps of requirements generation and management as it applies to IVHM systems, and demonstrate these with a "real-world" example related to designing a landing gear system. The team hopes that this paper and presentation will help start a dialog with the larger aerospace community and that the feedback can be used to improve the ARP and subsequently the practice of IVHM from a systems engineering point-of-view.

IVHM↗
DOE OSTI2023

Hand Calculation Methods for Nuclear Criticality Safety

This primer provides an overview of the most common hand calculation methods used for criticality safety calculations. The most widely used tools available to a nuclear criticality safety (NCS) practitioner are probably the common Monte Carlo or deterministic criticality safety codes, which can be used to model very complex systems. However, use of these codes can obscure the parameters to which a particular fissile system may be sensitive, whereas the hand calculation methods can be used to delve into the ways each parameter may affect the reactivity of a fissile material system. Furthermore, practitioners must avoid using computer codes as devices that take inputs and simply provide outputs (i.e., a “black box”). Many years ago, pioneers such as Joe Thomas, David Smith, and Hugh Paxton, among others in the field of nuclear criticality safety, took the time before the advent of high-speed desktop computers to create simple hand methods for criticality safety analyses. Some of the methods can be used for single fissile units; others are applicable to fissile units arranged into simple array configurations. This primer discusses the applicability of the various methods, illustrates how they are used, and provides an interpretation of the various results. The NCS practitioner will need to spend time to master the methods that could be most useful; however, they can provide the practitioner with fast and accurate answers to criticality safety problems if they are used correctly and if critical data exist for the problem at hand. Hand calculation methods can be used as a starting point for more advanced calculations, and in many circumstances, they can provide sensitivity and perturbation information more quickly than using a criticality code.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2021

Comparative evaluation of analogue front-end designs for the CMS Inner Tracker at the High Luminosity LHC

The CMS Inner Tracker, made of silicon pixel modules, will be entirely replaced prior to the start of the High Luminosity LHC period. One of the crucial components of the new Inner Tracker system is the readout chip, being developed by the RD53 Collaboration, and in particular its analogue front-end, which receives the signal from the sensor and digitizes it. Three different analogue front-ends (Synchronous, Linear, and Differential) were designed and implemented in the RD53A demonstrator chip. A dedicated evaluation program was carried out to select the most suitable design to build a radiation tolerant pixel detector able to sustain high particle rates with high efficiency and a small fraction of spurious pixel hits. The test results showed that all three analogue front-ends presented strong points, but also limitations. The Differential front-end demonstrated very low noise, but the threshold tuning became problematic after irradiation. Moreover, a saturation in the preamplifier feedback loop affected the return of the signal to baseline and thus increased the dead time. The Synchronous front-end showed very good timing performance, but also higher noise. For the Linear front-end all of the parameters were within specification, although this design had the largest time walk. This limitation was addressed and mitigated in an improved design. The analysis of the advantages and disadvantages of the three front-ends in the context of the CMS Inner Tracker operation requirements led to the selection of the improved design Linear front-end for integration in the final CMS readout chip.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS1975

The effects of exposure to LN2 temperatures and 2.5 suns solar radiation on 30-cm ion thruster performance

An experimental test program was developed to demonstrate all 30 cm Hg-ion bombardment thruster functions over the thermal environment of several proposed missions. A 30 cm thruster with grids dished 1.25 cm and instrumented with 31 thermocouples, was placed in a vacuum tank equipped with -196 C walls. Cold storage of a thruster was simulated and temperatures as low as -100 C were attained on the thruster. The thruster started successfully from these cold conditions. The thruster operating at both half and full beam power was exposed to 2.5 suns on axis solar simulation. Various thruster thermal configurations, used to simulate multiple thruster operation, were tested at the above conditions. The results of these tests are reported herein.

Mirtich, M. J.↗
NASA NTRS1984

Application of the generalized reduced gradient method to conceptual aircraft design

The complete aircraft design process can be broken into three phases of increasing depth: conceptual design, preliminary design, and detail design. Conceptual design consists primarily of developing general arrangements and selecting the configuration that optimally satisfies all mission requirements. The result of the conceptual phase is a conceptual baseline configuration that serves as the starting point for the preliminary design phase. The conceptual design of an aircraft involves a complex trade-off of many independent variables that must be investigated before deciding upon the basic configuration. Some of these variables are discrete (number of engines), some represent different configurations (canard vs conventional tail) and some may represent incorporation of new technologies (aluminum vs composite materials). At Lockheed-Georgia, the sizing program is known as GASP (Generalized Aircraft Sizing Program). GASP is a large program containing analysis modules covering the many different disciplines involved fin defining the aricraft, such as aerodynamics, structures, stability and control, mission performance, and cost. These analysis modules provide first-level estimates the aircraft properties that are derived from handbook, experimental, and historical sources.

Gabriele, G. A.↗
NASA NTRS1994

NASA's Man-Systems Integration Standards: A Human Factors Engineering Standard for Everyone in the Nineties

During the second half of the 1980s, a document was created by the National Aeronautics and Space Administration (NASA) to aid in the application of good human factors engineering and human interface practices to the design and development of hardware and systems for use in all United States manned space flight programs. This comprehensive document, known as NASA-STD-3000, the Man-Systems Integration Standards (MSIS), attempts to address, from a human factors engineering/human interface standpoint, all of the various types of equipment with which manned space flight crew members must deal. Basically, all of the human interface situations addressed in the MSIS are present in terrestrially based systems also. The premise of this paper is that, starting with this already created standard, comprehensive documents addressing human factors engineering and human interface concerns could be developed to aid in the design of almost any type of equipment or system which humans interface with in any terrestrial environment. Utilizing the systems and processes currently in place in the MSIS Development Facility at the Johnson Space Center in Houston, TX, any number of MSIS volumes addressing the human factors / human interface needs of any terrestrially based (or, for that matter, airborne) system could be created.

Cletis R. Booher↗
NASA NTRS2000

Partnering to Change the Way NASA and the Nation Communicate Through Space

For at least 20 years, the Space Communications Program at NASA Glenn Research Center (GRC) has focused on enhancing the capability and competitiveness of the U.S. commercial communications satellite industry. GRC has partnered with the industry on the development of enabling technologies to help maintain U.S. preeminence in the worldwide communications satellite marketplace. The Advanced Communications Technology Satellite (ACTS) has been the most significant space communications technology endeavor ever performed at GRC, and the centerpiece of GRC's communication technology program for the last decade. Under new sponsorship from NASA's Human Exploration and Development of Space Enterprise, GRC has transitioned the focus and direction of its program, from commercial relevance to NASA mission relevance. Instead of one major experimental spacecraft and one headquarters sponsor, GRC is now exploring opportunities for all of NASA's Enterprises to benefit from advances in space communications technologies, and accomplish their missions through the use of existing and emerging commercially provided services. A growing vision within NASA is to leverage the best commercial standards, technologies, and services as a starting point to satisfy NASA's unique needs. GRC's heritage of industry partnerships is closely aligned with this vision. NASA intends to leverage the explosive growth of the telecommunications industry through its impressive technology advancements and potential new commercial satellite systems. GRC's partnerships with the industry, academia, and other government agencies will directly support all four NASA's future mission needs, while advancing the state of the art of commercial practice. GRC now conducts applied research and develops and demonstrates advanced communications and network technologies in support of all four NASA Enterprises (Human Exploration and Development of Space, Space Science, Earth Science, and Aero-Space Technologies).

Vrotsos, Pete A.↗
NASA NTRS2010

Processing AIRS Scientific Data Through Level 3

The Atmospheric Infra-Red Sounder (AIRS) Science Processing System (SPS) is a collection of computer programs, known as product generation executives (PGEs). The AIRS SPS PGEs are used for processing measurements received from the AIRS suite of infrared and microwave instruments orbiting the Earth onboard NASA's Aqua spacecraft. Early stages of the AIRS SPS development were described in a prior NASA Tech Briefs article: Initial Processing of Infrared Spectral Data (NPO-35243), Vol. 28, No. 11 (November 2004), page 39. In summary: Starting from Level 0 (representing raw AIRS data), the AIRS SPS PGEs and the data products they produce are identified by alphanumeric labels (1A, 1B, 2, and 3) representing successive stages or levels of processing. The previous NASA Tech Briefs article described processing through Level 2, the output of which comprises geo-located atmospheric data products such as temperature and humidity profiles among others. The AIRS Level 3 PGE samples selected information from the Level 2 standard products to produce a single global gridded product. One Level 3 product is generated for each day s collection of Level 2 data. In addition, daily Level 3 products are aggregated into two multiday products: an eight-day (half the orbital repeat cycle) product and monthly (calendar month) product.

Granger, Stephanie↗
NASA NTRS2012

Anaphylaxis, Intra-Abdominal Infections, Skin Lacerations, and Behavioral Emergencies: A Literature Review of Austere Analogs for a near Earth Asteroid Mission

As space exploration is directed towards destinations beyond low-Earth orbit, the consequent new set of medical risks will drive requirements for new capabilities and more resources to ensure crew health. The Space Medicine Exploration Medical Conditions List (SMEMCL), developed by the Exploration Medical Capability element of the Human Research Program, addresses the risk of "unacceptable health and mission outcomes due to limitations of in-flight medical capabilities". It itemizes 85 evidence-based clinical requirements for eight different mission profiles and identifies conditions warranting further research and technology development. Each condition is given a clinical priority for each mission profile. Four conditions -- intra-abdominal infections, skin lacerations, anaphylaxis, and behavioral emergencies -- were selected as a starting point for analysis. A systematic literature review was performed to understand how these conditions are treated in austere, limited-resource, space-analog environments (i.e., high-altitude and mountain environments, submarines, military deployments, Antarctica, isolated wilderness environments, in-flight environments, and remote, resource-poor, rural environments). These environments serve as analogs to spaceflight because of their shared characteristics (limited medical resources, delay in communication, confined living quarters, difficulty with resupply, variable time to evacuation). Treatment of these four medical conditions in austere environments provides insight into medical equipment and training requirements for exploration-class missions.

Chough, Natacha G.↗
NASA NTRS2023

P-ACTIVE Project Report

The Phase change material-based actively-tunable filter (P-ACTIVE, Dr. Hyun Jung Kim, the Principal Investigator / PI) project is a NASA Langley Research Center (LaRC)-led research endeavor that began as a NASA CIF (Center Innovation Fund) project in 2019. The goal of P-ACTIVE is to develop all-solid-state tunable optical filters that can serve as low-Size, Weight, and Power (SWaP) replacements to the ubiquitous filter wheel technology current in use, and serve as a starting point for completely new optical component technologies. By using materials commonly used in electronic memory devices, namely chalcogenide phase-change materials (PCMs), in conjunction with nanostructured surfaces with exotic, tailored optical responses (“metasurfaces”), the P-ACTIVE filters are able to tune their optical transmission/reflection behavior in real-time. Because of this new functionality, P-ACTIVE filters are highlighted for NASA science and space programs such as next generation Lidar, landing system (SLS) thermal monitoring, thermal imaging, imaging spectroscopy, and disaster monitoring (e.g., volcanic eruption observations from SmallSats). This document intends to serve as a compendium of the P-ACTIVE project. We begin by describing the project from background science and assume no prior knowledge of the subject. We then address experimental and theoretical results of P-ACTIVE device performance, as well as recent results obtained from the MISSE-14 mission related to space qualification of P-ACTIVE devices and constituent materials. We conclude with a prospective view of the P-ACTIVE technology, and discuss the potential for these filters and other similar metasurface devices to serve NASA’s mission.

metamaterial↗
DOE OSTI2022

M4SF-22LL010301052-SUPCRTNE Thermodynamic Database Integration

This progress report (Level 4 Milestone Number M4SF-22LL010301052) summarizes research conducted at Lawrence Livermore National Laboratory (LLNL) within the Argillite Activity Number SF-22LL01030105. SUPCRTNE (starting with v. 1.0) is being developed as the primary engine for future thermodynamic database development. It replaces SUPCRT92 (Johnson et al., 1992), which was earlier used on the Yucca Mountain Project (Wolery and Jove-Colon, 2007). Various changes to SUPCRT92 were and are presently being made. A major change is replacing the original water properties module H2O92D. For this, we have developed a modularized form of the program H2OI95. H2OI95 (Wolery, 2018, 2020) evaluates a newer equation of state for water (IAPWS-95, (Wagner and Pruß, 2002)) that is the present international standard. Thermochemical properties including Gibbs energy, enthalpy, and entropy are now tied to the CODATA standard (Cox et al., 1989).

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1981

Solute partitioning under continuous cooling conditions as a cooling rate indicator

A model of solute partitioning in a finite body under conditions of continuous cooling is developed for the determination of cooling rates from concentration profile data, and applied to the partitioning of zirconium between ilmenite and ulvospinel in the Apollo 15 Elbow Crater rocks. Partitioning in a layered composite solid is described numerically in terms of concentration profiles and diffusion coefficients which are functions of time and temperature, respectively; a program based on the model can be used to calculate concentration profiles for various assumed cooling rates given the diffusion coefficients in the two phases and the equilibrium partitioning ratio over a range of temperatures. In the case of the Elbow Rock gabbros, the cooling rates are calculated from measured concentration ratios 10 microns from the interphase boundaries under the assumptions of uniform and equilibrium initial conditions at various starting temperatures. It is shown that the specimens could not have had uniform concentrations profiles at the previously suggested initial temperature of 1350 K. It is concluded that even under conditions where the initial temperature, grain sizes and solute diffusion coefficients are not well characterized, the model can be used to estimate the cooling rate of a grain assemblage to within an order of magnitude.

Onorato, P. I. K.↗
NASA NTRS1982

Concepts for large interferometers in space

Very high angular resolution can be achieved in optical and radio astronomy through interferometers in space. Evolutionary approaches and required technological advances are presented. In the optical region a phase-coherent array, (COSMIC) starting as a four-element linear array is discussed. Combining several modules results in greatly improved resolution with a goal of combining images to obtain a single field of view with 0.004 arcsecond resolution. The angular resolution, detail and temporal coverage of radio maps obtained by ground-based Very Long Interferometry (VLBI) can be greatly improved by placing one of the stations in earth orbit. An evolutionary program leading to a large aperture VLBI observatory in space is discussed.

Morgan, S. H.↗