Life-cycle environmental performance of renewable building materials in the context of residential construction : phase II research report : an extension to the 2005 phase I research report. Module N, Life-cycle inventory of manufacturing prefinished engineered wood flooring in the eastern United States

Treesearch

Richard D. Bergman; Scott A. Bowe

2011-01-01

This study summarizes the environmental performance of prefinished engineered wood flooring using life-cycle inventory (LCI) analysis. Using primary mill data gathered from manufacturers in the eastern United States and applying the methods found in Consortium for Research on Renewable Industrial Materials (CORRIM) Research Guidelines and International Organization of...

Life cycle inventory of manufacturing prefinished engineered wood flooring in eastern U.S. with comparison to solid strip wood flooring

Treesearch

Richard D. Bergman; Scott A. Bowe

2011-01-01

Building products have come under increased scrutiny because of environmental impacts from their manufacture. Our study followed the life cycle inventory approach for prefinished engineered wood flooring in the eastern US and compared the results with those of solid strip wood flooring. Our study surveyed five engineered wood flooring manufacturers in the eastern US....

Status of the Body of Knowledge and Curriculum to Advance Systems Engineering (BKCASE (trademark)) Project

DTIC Science & Technology

2011-10-01

Systems engineer- ing knowledge has also been documented through the standards bodies, most notably : • ISO /IEC/IEEE 15288, Systems Engineer- ing...System Life Cycle Processes, 2008 (see [10]). • ANSI/EIA 632, Processes for Engineering a System, (1998) • IEEE 1220, ISO /IEC 26702 Application...tion • United States Defense Acquisition Guidebook, Chapter 4, June 27, 2011 • IEEE/EIA 12207 , Software Life Cycle Processes, 2008 • United

Failure of engineering artifacts: a life cycle approach.

PubMed

Del Frate, Luca

2013-09-01

Failure is a central notion both in ethics of engineering and in engineering practice. Engineers devote considerable resources to assure their products will not fail and considerable progress has been made in the development of tools and methods for understanding and avoiding failure. Engineering ethics, on the other hand, is concerned with the moral and social aspects related to the causes and consequences of technological failures. But what is meant by failure, and what does it mean that a failure has occurred? The subject of this paper is how engineers use and define this notion. Although a traditional definition of failure can be identified that is shared by a large part of the engineering community, the literature shows that engineers are willing to consider as failures also events and circumstance that are at odds with this traditional definition. These cases violate one or more of three assumptions made by the traditional approach to failure. An alternative approach, inspired by the notion of product life cycle, is proposed which dispenses with these assumptions. Besides being able to address the traditional cases of failure, it can deal successfully with the problematic cases. The adoption of a life cycle perspective allows the introduction of a clearer notion of failure and allows a classification of failure phenomena that takes into account the roles of stakeholders involved in the various stages of a product life cycle.

Prospects for energy efficiency improvement and reduction of emissions and life cycle costs for natural gas vehicles

NASA Astrophysics Data System (ADS)

Kozlov, A. V.; Terenchenko, A. S.; Luksho, V. A.; Karpukhin, K. E.

2017-01-01

This work is devoted to the experimental investigation of the possibilities to reduce greenhouse gas emissions and to increase energy efficiency of engines that use natural gas as the main fuel and the analysis of economic efficiency of use of dual fuel engines in vehicles compared to conventional diesel. The results of experimental investigation of a 190 kW dual-fuel engine are presented; it is shown that quantitative and qualitative working process control may ensure thermal efficiency at the same level as that of the diesel engine and in certain conditions 5...8% higher. The prospects for reduction of greenhouse gas emissions have been assessed. The technical and economic evaluation of use of dual fuel engines in heavy-duty vehicles has been performed, taking into account the total life cycle. It is shown that it is possible to reduce life cycle costs by two times.

Research requirements to reduce civil helicopter life cycle cost

NASA Technical Reports Server (NTRS)

Blewitt, S. J.

1978-01-01

The problem of the high cost of helicopter development, production, operation, and maintenance is defined and the cost drivers are identified. Helicopter life cycle costs would decrease by about 17 percent if currently available technology were applied. With advanced technology, a reduction of about 30 percent in helicopter life cycle costs is projected. Technological and managerial deficiencies which contribute to high costs are examined, basic research and development projects which can reduce costs include methods for reduced fuel consumption; improved turbine engines; airframe and engine production methods; safety; rotor systems; and advanced transmission systems.

Increasing marketability and profitability of product line thru PATRAN and NASTRAN

NASA Technical Reports Server (NTRS)

Hyatt, Art

1989-01-01

Starting with the design objective the operational cycle life of the Swaging Tool was increased. To accomplish this increase in cycle life without increasing the size or weight of the tool would be engineering achievement. However, not only was the operational cycle life increased between 2 to 10 times but simultaneously the size and weight of the Swage Tool was decreased by about 50 percent. This accomplishment now becomes an outstanding engineering achievement. This achievement was only possible because of the computerized Patran, Nastran and Medusa programs.

Weibull-Based Design Methodology for Rotating Aircraft Engine Structures

NASA Technical Reports Server (NTRS)

Zaretsky, Erwin; Hendricks, Robert C.; Soditus, Sherry

2002-01-01

The NASA Energy Efficient Engine (E(sup 3)-Engine) is used as the basis of a Weibull-based life and reliability analysis. Each component's life and thus the engine's life is defined by high-cycle fatigue (HCF) or low-cycle fatigue (LCF). Knowing the cumulative life distribution of each of the components making up the engine as represented by a Weibull slope is a prerequisite to predicting the life and reliability of the entire engine. As the engine Weibull slope increases, the predicted lives decrease. The predicted engine lives L(sub 5) (95 % probability of survival) of approximately 17,000 and 32,000 hr do correlate with current engine maintenance practices without and with refurbishment. respectively. The individual high pressure turbine (HPT) blade lives necessary to obtain a blade system life L(sub 0.1) (99.9 % probability of survival) of 9000 hr for Weibull slopes of 3, 6 and 9, are 47,391 and 20,652 and 15,658 hr, respectively. For a design life of the HPT disks having probable points of failure equal to or greater than 36,000 hr at a probability of survival of 99.9 %, the predicted disk system life L(sub 0.1) can vary from 9,408 to 24,911 hr.

Project Interface Requirements Process Including Shuttle Lessons Learned

NASA Technical Reports Server (NTRS)

Bauch, Garland T.

2010-01-01

Most failures occur at interfaces between organizations and hardware. Processing interface requirements at the start of a project life cycle will reduce the likelihood of costly interface changes/failures later. This can be done by adding Interface Control Documents (ICDs) to the Project top level drawing tree, providing technical direction to the Projects for interface requirements, and by funding the interface requirements function directly from the Project Manager's office. The interface requirements function within the Project Systems Engineering and Integration (SE&I) Office would work in-line with the project element design engineers early in the life cycle to enhance communications and negotiate technical issues between the elements. This function would work as the technical arm of the Project Manager to help ensure that the Project cost, schedule, and risk objectives can be met during the Life Cycle. Some ICD Lessons Learned during the Space Shuttle Program (SSP) Life Cycle will include the use of hardware interface photos in the ICD, progressive life cycle design certification by analysis, test, & operations experience, assigning interface design engineers to Element Interface (EI) and Project technical panels, and linking interface design drawings with project build drawings

Towards a Sustainable Approach to Nanotechnology by Integrating Life Cycle Assessment into the Undergraduate Engineering Curriculum

ERIC Educational Resources Information Center

Kopelevich, Dmitry I.; Ziegler, Kirk J.; Lindner, Angela S.; Bonzongo, Jean-Claude J.

2012-01-01

Because rapid growth of nanotechnology is expected to lead to intentional and non-intentional releases, future engineers will need to minimize negative environmental and health impacts of nanomaterials. We developed two upper-level undergraduate courses centered on life-cycle assessment of nanomaterials. The first part of the course sequence…

Bypass control valve seal and bearing life cycle test report

NASA Technical Reports Server (NTRS)

Lundback, A. V.

1972-01-01

The operating characteristics of a bypass control valve seal and bearing life cycle tests are reported. Data from the initial assembly, leak, torque, and deflection tests are included along with the cycle life test results and conclusions. The equipment involved was to be used in the nuclear engine for the rocket vehicles program.

Methods Used to Support a Life Cycle of Complex Engineering Products

NASA Astrophysics Data System (ADS)

Zakharova, Alexandra A.; Kolegova, Olga A.; Nekrasova, Maria E.; Eremenko, Andrey O.

2016-08-01

Management of companies involved in the design, development and operation of complex engineering products recognize the relevance of creating systems for product lifecycle management. A system of methods is proposed to support life cycles of complex engineering products, based on fuzzy set theory and hierarchical analysis. The system of methods serves to demonstrate the grounds for making strategic decisions in an environment of uncertainty, allows the use of expert knowledge, and provides interconnection of decisions at all phases of strategic management and all stages of a complex engineering product lifecycle.

A Holistic Approach to Systems Development

NASA Technical Reports Server (NTRS)

Wong, Douglas T.

2008-01-01

Introduces a Holistic and Iterative Design Process. Continuous process but can be loosely divided into four stages. More effort spent early on in the design. Human-centered and Multidisciplinary. Emphasis on Life-Cycle Cost. Extensive use of modeling, simulation, mockups, human subjects, and proven technologies. Human-centered design doesn t mean the human factors discipline is the most important Disciplines should be involved in the design: Subsystem vendors, configuration management, operations research, manufacturing engineering, simulation/modeling, cost engineering, hardware engineering, software engineering, test and evaluation, human factors, electromagnetic compatibility, integrated logistics support, reliability/maintainability/availability, safety engineering, test equipment, training systems, design-to-cost, life cycle cost, application engineering etc. 9

Using Model-Based Systems Engineering To Provide Artifacts for NASA Project Life-Cycle and Technical Reviews

NASA Technical Reports Server (NTRS)

Parrott, Edith L.; Weiland, Karen J.

2017-01-01

The ability of systems engineers to use model-based systems engineering (MBSE) to generate self-consistent, up-to-date systems engineering products for project life-cycle and technical reviews is an important aspect for the continued and accelerated acceptance of MBSE. Currently, many review products are generated using labor-intensive, error-prone approaches based on documents, spreadsheets, and chart sets; a promised benefit of MBSE is that users will experience reductions in inconsistencies and errors. This work examines features of SysML that can be used to generate systems engineering products. Model elements, relationships, tables, and diagrams are identified for a large number of the typical systems engineering artifacts. A SysML system model can contain and generate most systems engineering products to a significant extent and this paper provides a guide on how to use MBSE to generate products for project life-cycle and technical reviews. The use of MBSE can reduce the schedule impact usually experienced for review preparation, as in many cases the review products can be auto-generated directly from the system model. These approaches are useful to systems engineers, project managers, review board members, and other key project stakeholders.

Engineering Changes in Product Design - A Review

NASA Astrophysics Data System (ADS)

Karthik, K.; Janardhan Reddy, K., Dr

2016-09-01

Changes are fundamental to product development. Engineering changes are unavoidable and can arise at any phase of the product life cycle. The consideration of market requirements, customer/user feedbacks, manufacturing constraints, design innovations etc., turning them into viable products can be accomplished when product change is managed properly. In the early design cycle, informal changes are accepted. However, changes become formal when its complexity and cost increases, and as product matures. To maximize the market shares, manufacturers have to effectively and efficiently manage engineering changes by means of Configuration Control. The paper gives a broad overview about ‘Engineering Change Management’ (ECM) through configuration management and its implications in product design. The aim is to give an idea and understanding about the engineering changes in product design scenario to the new researchers. This paper elaborates the significant aspect of managing the engineering changes and the importance of ECM in a product life cycle.

Current Status of an Organic Rankine Cycle Engine Development Program

NASA Technical Reports Server (NTRS)

Barber, R. E.

1984-01-01

The steps taken to achieve improved bearing life in the organic Rankine cycle (ORC) engine being developed for use on solar parabolic dishes are presented. A summary of test results is given. Dynamic tests on the machine shaft and rotors of the ORC engine are also discussed.

Using Screening Level Environmental Life Cycle Assessment to Aid Decision Making: A Case Study of a College Annual Report

ERIC Educational Resources Information Center

Ingwersen, Wesley W.; Curran, Mary Ann; Gonzalez, Michael A.; Hawkins, Troy R.

2012-01-01

Purpose: The purpose of this study is to compare the life cycle environmental impacts of the University of Cincinnati College of Engineering and Applied Sciences' current printed annual report to a version distributed via the internet. Design/methodology/approach: Life cycle environmental impacts of both versions of the report are modeled using…

Engineering empty space between Si nanoparticles for lithium-ion battery anodes.

PubMed

Wu, Hui; Zheng, Guangyuan; Liu, Nian; Carney, Thomas J; Yang, Yuan; Cui, Yi

2012-02-08

Silicon is a promising high-capacity anode material for lithium-ion batteries yet attaining long cycle life remains a significant challenge due to pulverization of the silicon and unstable solid-electrolyte interphase (SEI) formation during the electrochemical cycles. Despite significant advances in nanostructured Si electrodes, challenges including short cycle life and scalability hinder its widespread implementation. To address these challenges, we engineered an empty space between Si nanoparticles by encapsulating them in hollow carbon tubes. The synthesis process used low-cost Si nanoparticles and electrospinning methods, both of which can be easily scaled. The empty space around the Si nanoparticles allowed the electrode to successfully overcome these problems Our anode demonstrated a high gravimetric capacity (~1000 mAh/g based on the total mass) and long cycle life (200 cycles with 90% capacity retention). © 2012 American Chemical Society

Air Force Systems Engineering Assessment Model (AF SEAM) Management Guide, Version 2

DTIC Science & Technology

2010-09-21

gleaned from experienced professionals who assisted with the model’s development. Examples of the references used include the following: • ISO /IEC...Defense Acquisition Guidebook, Chapter 4 • AFI 63-1201, Life Cycle Systems Engineering • IEEE/EIA 12207 , Software Life Cycle Processes • Air...Selection criteria Reference Material: IEEE/EIA 12207 , MIL-HDBK-514 Other Considerations: Modeling, simulation and analysis techniques can be

The US Army Corps of Engineers Roadmap for Life-Cycle Building Information Modeling (BIM). Supplement 2 - BIM Implementation Guide for Military Construction (MILCON) Projects Using the Bentley Platform

DTIC Science & Technology

2012-11-01

Building Information Modeling ( BIM ...12-2, Supplement 2 November 2012 The US Army Corps of Engineers Roadmap for Life-Cycle Building Information Modeling ( BIM ) Supplement 2 – BIM ...39180 ERDC SR-12-2, Supplement 2 (November 2012) ii Abstract Building Information Modeling ( BIM ) technology has rapidly gained ac-

The US Army Corps of Engineers Roadmap for Life-Cycle Building Information Modeling (BIM). Supplement 1- BIM Implementation Guide for Military Construction (MILCON) Projects Using the Autodesk Platform

DTIC Science & Technology

2012-11-01

Building Information Modeling ( BIM ...12-2, Supplement 1 November 2012 The US Army Corps of Engineers Roadmap for Life-Cycle Building Information Modeling ( BIM ) Supplement 1 – BIM ...ERDC SR-12-2, Supplement 1 (November 2012) ii Abstract Building Information Modeling ( BIM ) technology has rapidly gained ac- ceptance throughout

40 CFR 1045.103 - What exhaust emission standards must my outboard and personal watercraft engines meet?

Code of Federal Regulations, 2011 CFR

2011-07-01

... emission standards must my outboard and personal watercraft engines meet? (a) Duty-cycle emission standards.... (3) Other engines: THC emissions. (e) Useful life. Your engines must meet the exhaust emission standards in paragraphs (a) through (c) of this section over the full useful life as follows: (1) For...

Electric vehicle life cycle cost analysis : final research project report.

DOT National Transportation Integrated Search

2017-02-01

This project compared total life cycle costs of battery electric vehicles (BEV), plug-in hybrid electric vehicles (PHEV), hybrid electric vehicles (HEV), and vehicles with internal combustion engines (ICE). The analysis considered capital and operati...

Using Model-Based Systems Engineering to Provide Artifacts for NASA Project Life-cycle and Technical Reviews

NASA Technical Reports Server (NTRS)

Parrott, Edith L.; Weiland, Karen J.

2017-01-01

This paper is for the AIAA Space Conference. The ability of systems engineers to use model-based systems engineering (MBSE) to generate self-consistent, up-to-date systems engineering products for project life-cycle and technical reviews is an important aspect for the continued and accelerated acceptance of MBSE. Currently, many review products are generated using labor-intensive, error-prone approaches based on documents, spreadsheets, and chart sets; a promised benefit of MBSE is that users will experience reductions in inconsistencies and errors. This work examines features of SysML that can be used to generate systems engineering products. Model elements, relationships, tables, and diagrams are identified for a large number of the typical systems engineering artifacts. A SysML system model can contain and generate most systems engineering products to a significant extent and this paper provides a guide on how to use MBSE to generate products for project life-cycle and technical reviews. The use of MBSE can reduce the schedule impact usually experienced for review preparation, as in many cases the review products can be auto-generated directly from the system model. These approaches are useful to systems engineers, project managers, review board members, and other key project stakeholders.

A Life-Cycle Assessment of Biofuels: Tracing Energy and Carbon through a Fuel-Production System

ERIC Educational Resources Information Center

Krauskopf, Sara

2010-01-01

A life-cycle assessment (LCA) is a tool used by engineers to make measurements of net energy, greenhouse gas production, water consumption, and other items of concern. This article describes an activity designed to walk students through the qualitative part of an LCA. It asks them to consider the life-cycle costs of ethanol production, in terms of…

Easy method of matching fighter engine to airframe for use in aircraft engine design courses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mattingly, J.D.

1989-01-01

The proper match of the engine(s) to the airframe affects both aircraft size and life cycle cost. A fast and straightforward method is developed and used for the matching of fighter engine(s) to airframes during conceptual design. A thrust-lapse equation is developed for the dual-spool, mixed-flow, afterburning turbofan type of engine based on the installation losses of 'Aircraft Engine Design' and the performance predictions of the cycle analysis programs ONX and OFFX. Using system performance requirements, the effects of aircraft thrust-to-weight, wing loading, and engine cycle on takeoff weight are analyzed and example design course results presented. 5 refs.

Optimizing conceptual aircraft designs for minimum life cycle cost

NASA Technical Reports Server (NTRS)

Johnson, Vicki S.

1989-01-01

A life cycle cost (LCC) module has been added to the FLight Optimization System (FLOPS), allowing the additional optimization variables of life cycle cost, direct operating cost, and acquisition cost. Extensive use of the methodology on short-, medium-, and medium-to-long range aircraft has demonstrated that the system works well. Results from the study show that optimization parameter has a definite effect on the aircraft, and that optimizing an aircraft for minimum LCC results in a different airplane than when optimizing for minimum take-off gross weight (TOGW), fuel burned, direct operation cost (DOC), or acquisition cost. Additionally, the economic assumptions can have a strong impact on the configurations optimized for minimum LCC or DOC. Also, results show that advanced technology can be worthwhile, even if it results in higher manufacturing and operating costs. Examining the number of engines a configuration should have demonstrated a real payoff of including life cycle cost in the conceptual design process: the minimum TOGW of fuel aircraft did not always have the lowest life cycle cost when considering the number of engines.

Probabilistic/Fracture-Mechanics Model For Service Life

NASA Technical Reports Server (NTRS)

Watkins, T., Jr.; Annis, C. G., Jr.

1991-01-01

Computer program makes probabilistic estimates of lifetime of engine and components thereof. Developed to fill need for more accurate life-assessment technique that avoids errors in estimated lives and provides for statistical assessment of levels of risk created by engineering decisions in designing system. Implements mathematical model combining techniques of statistics, fatigue, fracture mechanics, nondestructive analysis, life-cycle cost analysis, and management of engine parts. Used to investigate effects of such engine-component life-controlling parameters as return-to-service intervals, stresses, capabilities for nondestructive evaluation, and qualities of materials.

Ontology for Life-Cycle Modeling of Water Distribution Systems: Model View Definition

DTIC Science & Technology

2013-06-01

Research and Development Center, Construction Engineering Research Laboratory (ERDC-CERL) to develop a life-cycle building model have resulted in the...Laboratory (ERDC-CERL) to develop a life-cycle building model have resulted in the definition of a “core” building information model that contains...developed experimental BIM models us- ing commercial off-the-shelf (COTS) software. Those models represent three types of typical low-rise Army

Heat engine development for solar thermal power systems

NASA Technical Reports Server (NTRS)

Pham, H. Q.; Jaffe, L. D.

1981-01-01

The technical status of three heat engines (Stirling, high-temperature Brayton, and Combined cycle) for use in solar thermal power systems is presented. Performance goals necessary to develop a system competitive with conventional power requirements include an external heated engine output less than 40 kW, and efficiency power conversion subsystem at least 40% at rated output, and a half-power efficiency of at least 37%. Results show that the Stirling engine can offer a 39% efficiency with 100 hours of life, and a 20% efficiency with 10,000 hours of life, but problems with seals and heater heads exist. With a demonstrated efficiency near 31% at 1500 F and a minimum lifetime of 100,000 hours, the Brayton engine does not offer sufficient engine lifetime, efficiency, and maintenance for solar thermal power systems. Examination of the Rankine bottoming cycle of the Combined cycle engine reveals a 30 year lifetime, but a low efficiency. Additional development of engines for solar use is primarily in the areas of components to provide a long lifetime, high reliability, and low maintenance (no more than $0.001/kW-hr).

Using screening level environmental life cycle assessment to aid decision making: A case study of a college annual report

EPA Science Inventory

Purpose – In this study we compare the life cycle environmental impacts of the University of Cincinnati College of Engineering and Applied Sciences’ current printed annual report to a version distributed via the Internet. This case study demonstrates how a screening level life cy...

A simplified life-cycle cost comparison of various engines for small helicopter use

NASA Technical Reports Server (NTRS)

Civinskas, K. C.; Fishbach, L. M.

1974-01-01

A ten-year, life-cycle cost comparison is made of the following engines for small helicopter use: (1) simple turboshaft; (2) regenerative turboshaft; (3) compression-ignition reciprocator; (4) spark-ignited rotary; and (5) spark-ignited reciprocator. Based on a simplified analysis and somewhat approximate data, the simple turboshaft engine apparently has the lowest costs for mission times up to just under 2 hours. At 2 hours and above, the regenerative turboshaft appears promising. The reciprocating and rotary engines are less attractive, requiring from 10 percent to 80 percent more aircraft to have the same total payload capability as a given number of turbine powered craft. A nomogram was developed for estimating total costs of engines not covered in this study.

LIFE CYCLE DESIGN GUIDANCE MANUAL - ENVIRONMENTAL REQUIREMENTS AND THE PRODUCT SYSTEM

EPA Science Inventory

The U.S Environmental Protection Agency's (EPA) Risk Reduction Engineering Laboratory and the University of Michigan are cooperating in a project to reduce environmental impacts and health risks through product system design. The resulting framework for life cycle design is pr...

Problems of the high-cycle fatigue of the materials intended for the parts of modern gas-turbine engines and power plants

NASA Astrophysics Data System (ADS)

Petukhov, A. N.

2010-10-01

The problems related to the determination of the life of the structural materials applied for important parts in gas-turbine engines and power plants from the results of high-cycle fatigue tests are discussed. Methods for increasing the reliability of the high-cycle fatigue characteristics and the factors affecting the operational reliability are considered.

From cradle-to-grave at the nanoscale: gaps in U.S. regulatory oversight along the nanomaterial life cycle.

PubMed

Beaudrie, Christian E H; Kandlikar, Milind; Satterfield, Terre

2013-06-04

Engineered nanomaterials (ENMs) promise great benefits for society, yet our knowledge of potential risks and best practices for regulation are still in their infancy. Toward the end of better practices, this paper analyzes U.S. federal environmental, health, and safety (EHS) regulations using a life cycle framework. It evaluates their adequacy as applied to ENMs to identify gaps through which emerging nanomaterials may escape regulation from initial production to end-of-life. High scientific uncertainty, a lack of EHS and product data, inappropriately designed exemptions and thresholds, and limited agency resources are a challenge to both the applicability and adequacy of current regulations. The result is that some forms of engineered nanomaterials may escape federal oversight and rigorous risk review at one or more stages along their life cycle, with the largest gaps occurring at the postmarket stages, and at points of ENM release to the environment. Oversight can be improved through pending regulatory reforms, increased research and development for the monitoring, control, and analysis of environmental and end-of-life releases, introduction of periodic re-evaluation of ENM risks, and fostering a "bottom-up" stewardship approach to the responsible management of risks from engineered nanomaterials.

Determination of Turbine Blade Life from Engine Field Data

NASA Technical Reports Server (NTRS)

Zaretsky, Erwin V.; Litt, Jonathan S.; Hendricks, Robert C.; Soditus, Sherry M.

2013-01-01

It is probable that no two engine companies determine the life of their engines or their components in the same way or apply the same experience and safety factors to their designs. Knowing the failure mode that is most likely to occur minimizes the amount of uncertainty and simplifies failure and life analysis. Available data regarding failure mode for aircraft engine blades, while favoring low-cycle, thermal-mechanical fatigue (TMF) as the controlling mode of failure, are not definitive. Sixteen high-pressure turbine (HPT) T-1 blade sets were removed from commercial aircraft engines that had been commercially flown by a single airline and inspected for damage. Each set contained 82 blades. The damage was cataloged into three categories related to their mode of failure: (1) TMF, (2) Oxidation/erosion (O/E), and (3) Other. From these field data, the turbine blade life was determined as well as the lives related to individual blade failure modes using Johnson-Weibull analysis. A simplified formula for calculating turbine blade life and reliability was formulated. The L10 blade life was calculated to be 2427 cycles (11 077 hr). The resulting blade life attributed to O/E equaled that attributed to TMF. The category that contributed most to blade failure was Other. If there were no blade failures attributed to O/E and TMF, the overall blade L(sub 10) life would increase approximately 11 to 17 percent.

Neutronics Design of a Thorium-Fueled Fission Blanket for LIFE (Laser Inertial Fusion-based Energy)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Powers, J; Abbott, R; Fratoni, M

The Laser Inertial Fusion-based Energy (LIFE) project at LLNL includes development of hybrid fusion-fission systems for energy generation. These hybrid LIFE engines use high-energy neutrons from laser-based inertial confinement fusion to drive a subcritical blanket of fission fuel that surrounds the fusion chamber. The fission blanket contains TRISO fuel particles packed into pebbles in a flowing bed geometry cooled by a molten salt (flibe). LIFE engines using a thorium fuel cycle provide potential improvements in overall fuel cycle performance and resource utilization compared to using depleted uranium (DU) and may minimize waste repository and proliferation concerns. A preliminary engine designmore » with an initial loading of 40 metric tons of thorium can maintain a power level of 2000 MW{sub th} for about 55 years, at which point the fuel reaches an average burnup level of about 75% FIMA. Acceptable performance was achieved without using any zero-flux environment 'cooling periods' to allow {sup 233}Pa to decay to {sup 233}U; thorium undergoes constant irradiation in this LIFE engine design to minimize proliferation risks and fuel inventory. Vast reductions in end-of-life (EOL) transuranic (TRU) inventories compared to those produced by a similar uranium system suggest reduced proliferation risks. Decay heat generation in discharge fuel appears lower for a thorium LIFE engine than a DU engine but differences in radioactive ingestion hazard are less conclusive. Future efforts on development of thorium-fueled LIFE fission blankets engine development will include design optimization, fuel performance analysis work, and further waste disposal and nonproliferation analyses.« less

Tracking and Control of Gas Turbine Engine Component Damage/Life

NASA Technical Reports Server (NTRS)

Jaw, Link C.; Wu, Dong N.; Bryg, David J.

2003-01-01

This paper describes damage mechanisms and the methods of controlling damages to extend the on-wing life of critical gas turbine engine components. Particularly, two types of damage mechanisms are discussed: creep/rupture and thermo-mechanical fatigue. To control these damages and extend the life of engine hot-section components, we have investigated two methodologies to be implemented as additional control logic for the on-board electronic control unit. This new logic, the life-extending control (LEC), interacts with the engine control and monitoring unit and modifies the fuel flow to reduce component damages in a flight mission. The LEC methodologies were demonstrated in a real-time, hardware-in-the-loop simulation. The results show that LEC is not only a new paradigm for engine control design, but also a promising technology for extending the service life of engine components, hence reducing the life cycle cost of the engine.

Systems engineering aspects of a preliminary conceptual design of the space station environmental control and life support system

NASA Technical Reports Server (NTRS)

Lin, C. H.; Meyer, M. S.

1983-01-01

The systems engineering aspects of developing a conceptual design of the Space Station Environmental Control and Life Support System (ECLSS) are discussed. Topics covered include defining system requirements and groundrules for approach, formulating possible cycle closure options, and establishing a system-level mass balance on the essential materials processed in oxygen and water cycles. Consideration is also given to the performance of a system trade-off study to determine the best degree of cycle closure for the ECLSS, and the construction of a conceptual design of the ECLSS with subsystem performance specifications and candidate concepts. For the optimum balance between development costs, technological risks, and resupply penalties, a partially closed cycle ECLSS option is suggested.

Systems engineering real estate development projects

NASA Astrophysics Data System (ADS)

Gusakova, Elena; Titarenko, Boris; Stepanov, Vitaliy

2017-10-01

In recent years, real estate development has accumulated a wealth of experience in implementing major projects, which requires comprehension and systematization. The scientific instrument of system engineering is studied in the article and is substantively interpreted with reference to real estate development projects. The most perspective approaches and models are substantiated, allowing strategically to plan the life cycle of the project as a whole, and also to solve the engineering butt problems of the project. The relevance of further scientific studies of regularities and specifics of the life cycle of real estate development projects conducted at the Moscow State University of Economics and Management at the ISTA department is shown.

A Treatise on the Application of Life Cycle Management Principles in Agricultural & Biological Engineering

USDA-ARS?s Scientific Manuscript database

Life Cycle Management (LCM) is a systematic approach, mindset and culture that considers economic, social, and environmental factors among other factors in the decision making process throughout various business or organizational decisions that affect both inputs and outputs of a product or service...

Designing for the ISD Life Cycle.

ERIC Educational Resources Information Center

Wallace, Guy W.; Hybert, Peter R.; Smith, Kelly R.; Blecke, Brian D.

2002-01-01

Outlines the recent criticisms of traditional ISD (Instructional Systems Design) and discusses the implications that impact the life cycle costs of T&D (Training and Development) projects and their ROI (Return On Investment) potential. Describes a modified approach to ISD which mimics the modular approach of systems engineering design.…

From Centralized Disassembly to Life Cycle Management: Status and Progress of E-waste Treatment System in China

NASA Astrophysics Data System (ADS)

Song, Xiaolong; Yang, Jianxin; Lu, Bin; Yang, Dong

2017-01-01

China is now facing e-waste problems from both growing domestic generation and illegal imports. Many stakeholders are involved in the e-waste treatment system due to the complexity of e-waste life cycle. Beginning with the state of the e-waste treatment industry in China, this paper summarizes the latest progress in e-waste management from such aspects as the new edition of the China RoHS Directive, new Treatment List, new funding subsidy standard, and eco-design pilots. Thus, a conceptual model for life cycle management of e-waste is generalized. The operating procedure is to first identify the life cycle stages of the e-waste and extract the important life cycle information. Then, life cycle tools can be used to conduct a systematic analysis to help decide how to maximize the benefits from a series of life cycle engineering processes. Meanwhile, life cycle thinking is applied to improve the legislation relating to e-waste so as to continuously improve the sustainability of the e-waste treatment system. By providing an integrative framework, the life cycle management of e-waste should help to realize sustainable management of e-waste in developing countries.

A Combined High and Low Cycle Fatigue Model for Life Prediction of Turbine Blades

PubMed Central

Yue, Peng; Yu, Zheng-Yong; Wang, Qingyuan

2017-01-01

Combined high and low cycle fatigue (CCF) generally induces the failure of aircraft gas turbine attachments. Based on the aero-engine load spectrum, accurate assessment of fatigue damage due to the interaction of high cycle fatigue (HCF) resulting from high frequency vibrations and low cycle fatigue (LCF) from ground-air-ground engine cycles is of critical importance for ensuring structural integrity of engine components, like turbine blades. In this paper, the influence of combined damage accumulation on the expected CCF life are investigated for turbine blades. The CCF behavior of a turbine blade is usually studied by testing with four load-controlled parameters, including high cycle stress amplitude and frequency, and low cycle stress amplitude and frequency. According to this, a new damage accumulation model is proposed based on Miner’s rule to consider the coupled damage due to HCF-LCF interaction by introducing the four load parameters. Five experimental datasets of turbine blade alloys and turbine blades were introduced for model validation and comparison between the proposed Miner, Manson-Halford, and Trufyakov-Kovalchuk models. Results show that the proposed model provides more accurate predictions than others with lower mean and standard deviation values of model prediction errors. PMID:28773064

A Combined High and Low Cycle Fatigue Model for Life Prediction of Turbine Blades.

PubMed

Zhu, Shun-Peng; Yue, Peng; Yu, Zheng-Yong; Wang, Qingyuan

2017-06-26

Combined high and low cycle fatigue (CCF) generally induces the failure of aircraft gas turbine attachments. Based on the aero-engine load spectrum, accurate assessment of fatigue damage due to the interaction of high cycle fatigue (HCF) resulting from high frequency vibrations and low cycle fatigue (LCF) from ground-air-ground engine cycles is of critical importance for ensuring structural integrity of engine components, like turbine blades. In this paper, the influence of combined damage accumulation on the expected CCF life are investigated for turbine blades. The CCF behavior of a turbine blade is usually studied by testing with four load-controlled parameters, including high cycle stress amplitude and frequency, and low cycle stress amplitude and frequency. According to this, a new damage accumulation model is proposed based on Miner's rule to consider the coupled damage due to HCF-LCF interaction by introducing the four load parameters. Five experimental datasets of turbine blade alloys and turbine blades were introduced for model validation and comparison between the proposed Miner, Manson-Halford, and Trufyakov-Kovalchuk models. Results show that the proposed model provides more accurate predictions than others with lower mean and standard deviation values of model prediction errors.

NASA Systems Engineering Handbook

NASA Technical Reports Server (NTRS)

2007-01-01

This handbook is intended to provide general guidance and information on systems engineering that will be useful to the NASA community. It provides a generic description of Systems Engineering (SE) as it should be applied throughout NASA. A goal of the handbook is to increase awareness and consistency across the Agency and advance the practice of SE. This handbook provides perspectives relevant to NASA and data particular to NASA. The coverage in this handbook is limited to general concepts and generic descriptions of processes, tools, and techniques. It provides information on systems engineering best practices and pitfalls to avoid. There are many Center-specific handbooks and directives as well as textbooks that can be consulted for in-depth tutorials. This handbook describes systems engineering as it should be applied to the development and implementation of large and small NASA programs and projects. NASA has defined different life cycles that specifically address the major project categories, or product lines, which are: Flight Systems and Ground Support (FS&GS), Research and Technology (R&T), Construction of Facilities (CoF), and Environmental Compliance and Restoration (ECR). The technical content of the handbook provides systems engineering best practices that should be incorporated into all NASA product lines. (Check the NASA On-Line Directives Information System (NODIS) electronic document library for applicable NASA directives on topics such as product lines.) For simplicity this handbook uses the FS&GS product line as an example. The specifics of FS&GS can be seen in the description of the life cycle and the details of the milestone reviews. Each product line will vary in these two areas; therefore, the reader should refer to the applicable NASA procedural requirements for the specific requirements for their life cycle and reviews. The engineering of NASA systems requires a systematic and disciplined set of processes that are applied recursively and iteratively for the design, development, operation, maintenance, and closeout of systems throughout the life cycle of the programs and projects.

A software engineering approach to expert system design and verification

NASA Technical Reports Server (NTRS)

Bochsler, Daniel C.; Goodwin, Mary Ann

1988-01-01

Software engineering design and verification methods for developing expert systems are not yet well defined. Integration of expert system technology into software production environments will require effective software engineering methodologies to support the entire life cycle of expert systems. The software engineering methods used to design and verify an expert system, RENEX, is discussed. RENEX demonstrates autonomous rendezvous and proximity operations, including replanning trajectory events and subsystem fault detection, onboard a space vehicle during flight. The RENEX designers utilized a number of software engineering methodologies to deal with the complex problems inherent in this system. An overview is presented of the methods utilized. Details of the verification process receive special emphasis. The benefits and weaknesses of the methods for supporting the development life cycle of expert systems are evaluated, and recommendations are made based on the overall experiences with the methods.

Life cycle cost assessment of future low heat rejection engines

NASA Technical Reports Server (NTRS)

Petersen, D. R.

1986-01-01

The Adiabatic Diesel Engine Component Development (ADECD) represents a project which has the objective to accelerate the development of highway truck engines with advanced technology aimed at reduced fuel consumption. The project comprises three steps, including the synthesis of a number of engine candidate designs, the coupling of each with a number of systems for utilizing exhaust gas energy, and the evaluation of each combination in terms of desirability. Particular attention is given to the employed evaluation method and the development of this method. The objective of Life Cycle Cost (LCC) evaluation in the ADECD program was to select the best from among 42 different low heat rejection engine (LHRE)/exhaust energy recovery system configurations. The LCC model is discussed along with a maintenance cost model, the evaluation strategy, the selection of parameter ranges, and a full factorial analysis.

Reusability aspects for space transportation rocket engines: programmatic status and outlook

NASA Astrophysics Data System (ADS)

Preclik, D.; Strunz, R.; Hagemann, G.; Langel, G.

2011-09-01

Rocket propulsion systems belong to the most critical subsystems of a space launch vehicle, being illustrated in this paper by comparing different types of transportation systems. The aspect of reusability is firstly discussed for the space shuttle main engine, the only rocket engine in the world that has demonstrated multiple reuses. Initial projections are contrasted against final reusability achievements summarizing three decades of operating the space shuttle main engine. The discussion is then extended to engines employed on expendable launch vehicles with an operational life requirement typically specifying structural integrities up to 20 cycles (start-ups) and an accumulated burning time of about 6,000 s (Vulcain engine family). Today, this life potential substantially exceeds the duty cycle of an expendable engine. It is actually exploited only during the development and qualification phase of an engine when system reliability is demonstrated on ground test facilities with a reduced number of hardware sets that are subjected to an extended number of test cycles and operation time. The paper will finally evaluate the logic and effort necessary to qualify a reusable engine for a required reliability and put this result in context of possible cost savings realized from reuse operations over a time span of 25 years.

Tailoring Systems Engineering Processes in a Conceptual Design Environment: A Case Study at NASA Marshall Spaceflight Center's ACO

NASA Technical Reports Server (NTRS)

Mulqueen, John; Maples, C. Dauphne; Fabisinski, Leo, III

2012-01-01

This paper provides an overview of Systems Engineering as it is applied in a conceptual design space systems department at the National Aeronautics and Space Administration (NASA) Marshall Spaceflight Center (MSFC) Advanced Concepts Office (ACO). Engineering work performed in the NASA MFSC's ACO is targeted toward the Exploratory Research and Concepts Development life cycle stages, as defined in the International Council on Systems Engineering (INCOSE) System Engineering Handbook. This paper addresses three ACO Systems Engineering tools that correspond to three INCOSE Technical Processes: Stakeholder Requirements Definition, Requirements Analysis, and Integration, as well as one Project Process Risk Management. These processes are used to facilitate, streamline, and manage systems engineering processes tailored for the earliest two life cycle stages, which is the environment in which ACO engineers work. The role of systems engineers and systems engineering as performed in ACO is explored in this paper. The need for tailoring Systems Engineering processes, tools, and products in the ever-changing engineering services ACO provides to its customers is addressed.

Using trading zones and life cycle analysis to understand nanotechnology regulation.

PubMed

Wardak, Ahson; Gorman, Michael E

2006-01-01

This article reviews the public health and environmental regulations applicable to nanotechnology using a life cycle model from basic research through end-of-life for products. Given nanotechnology's immense promise and public investment, regulations are important, balancing risk with the public good. Trading zones and earth systems engineering management assist in explaining potential solutions to gaps in an otherwise complex, overlapping regulatory system.

Life cycle models of conventional and alternative-fueled automobiles

NASA Astrophysics Data System (ADS)

Maclean, Heather Louise

This thesis reports life cycle inventories of internal combustion engine automobiles with feasible near term fuel/engine combinations. These combinations include unleaded gasoline, California Phase 2 Reformulated Gasoline, alcohol and gasoline blends (85 percent methanol or ethanol combined with 15 percent gasoline), and compressed natural gas in spark ignition direct and indirect injection engines. Additionally, I consider neat methanol and neat ethanol in spark ignition direct injection engines and diesel fuel in compression ignition direct and indirect injection engines. I investigate the potential of the above options to have a lower environmental impact than conventional gasoline-fueled automobiles, while still retaining comparable pricing and consumer benefits. More broadly, the objective is to assess whether the use of any of the alternative systems will help to lead to the goal of a more sustainable personal transportation system. The principal tool is the Economic Input-Output Life Cycle Analysis model which includes inventories of economic data, environmental discharges, and resource use. I develop a life cycle assessment framework to assemble the array of data generated by the model into three aggregate assessment parameters; economics, externalities, and vehicle attributes. The first step is to develop a set of 'comparable cars' with the alternative fuel/engine combinations, based on characteristics of a conventional 1998 gasoline-fueled Ford Taurus sedan, the baseline vehicle for the analyses. I calculate the assessment parameters assuming that these comparable cars can attain the potential thermal efficiencies estimated by experts for each fuel/engine combination. To a first approximation, there are no significant differences in the assessment parameters for the vehicle manufacture, service, fixed costs, and the end-of-life for any of the options. However, there are differences in the vehicle operation life cycle components and the state of technology development for the combinations. Overall, none of the alternatives emerges as a clear winner, lowering the externalities and improving sustainability, while considering technology issues and vehicle attributes. The majority of the alternatives are not likely to displace the baseline automobile. However, the attractiveness of the alternatives depends on the focus of future regulations, government priorities, and technology development. If long-term global sustainability is the principal concern, then improvements in fuel economy alone will not provide the level of reduction in impact required. A switch to renewable fuels (e.g., alcohols or diesel produced from biomass) to power the vehicles will likely be necessary. (Abstract shortened by UMI.)

Analysis of environmental factors impacting the life cycle cost analysis of conventional and fuel cell/battery-powered passenger vehicles. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This report presents the results of the further developments and testing of the Life Cycle Cost (LCC) Model previously developed by Engineering Systems Management, Inc. (ESM) on behalf of the U.S. Department of Energy (DOE) under contract No. DE-AC02-91CH10491. The Model incorporates specific analytical relationships and cost/performance data relevant to internal combustion engine (ICE) powered vehicles, battery powered electric vehicles (BPEVs), and fuel cell/battery-powered electric vehicles (FCEVs).

Enterprise and system of systems capability development life-cycle processes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beck, David Franklin

2014-08-01

This report and set of appendices are a collection of memoranda originally drafted circa 2007-2009 for the purpose of describing and detailing a models-based systems engineering approach for satisfying enterprise and system-of-systems life cycle process requirements. At the time there was interest and support to move from Capability Maturity Model Integration (CMMI) Level One (ad hoc processes) to Level Three. The main thrust of the material presents a rational exposâe of a structured enterprise development life cycle that uses the scientific method as a framework, with further rigor added from adapting relevant portions of standard systems engineering processes. While themore » approach described invokes application of the Department of Defense Architectural Framework (DoDAF), it is suitable for use with other architectural description frameworks.« less

Construction Performance Optimization toward Green Building Premium Cost Based on Greenship Rating Tools Assessment with Value Engineering Method

NASA Astrophysics Data System (ADS)

Latief, Yusuf; Berawi, Mohammed Ali; Basten, Van; Riswanto; Budiman, Rachmat

2017-07-01

Green building concept becomes important in current building life cycle to mitigate environment issues. The purpose of this paper is to optimize building construction performance towards green building premium cost, achieving green building rating tools with optimizing life cycle cost. Therefore, this study helps building stakeholder determining building fixture to achieve green building certification target. Empirically the paper collects data of green building in the Indonesian construction industry such as green building fixture, initial cost, operational and maintenance cost, and certification score achievement. After that, using value engineering method optimized green building fixture based on building function and cost aspects. Findings indicate that construction performance optimization affected green building achievement with increasing energy and water efficiency factors and life cycle cost effectively especially chosen green building fixture.

Determination of Turbine Blade Life from Engine Field Data

NASA Technical Reports Server (NTRS)

Zaretsky, Erwin V.; Litt, Jonathan S.; Hendricks, Robert C.; Soditus, Sherry M.

2012-01-01

It is probable that no two engine companies determine the life of their engines or their components in the same way or apply the same experience and safety factors to their designs. Knowing the failure mode that is most likely to occur minimizes the amount of uncertainty and simplifies failure and life analysis. Available data regarding failure mode for aircraft engine blades, while favoring low-cycle, thermal mechanical fatigue as the controlling mode of failure, are not definitive. Sixteen high-pressure turbine (HPT) T-1 blade sets were removed from commercial aircraft engines that had been commercially flown by a single airline and inspected for damage. Each set contained 82 blades. The damage was cataloged into three categories related to their mode of failure: (1) Thermal-mechanical fatigue, (2) Oxidation/Erosion, and (3) "Other." From these field data, the turbine blade life was determined as well as the lives related to individual blade failure modes using Johnson-Weibull analysis. A simplified formula for calculating turbine blade life and reliability was formulated. The L(sub 10) blade life was calculated to be 2427 cycles (11 077 hr). The resulting blade life attributed to oxidation/erosion equaled that attributed to thermal-mechanical fatigue. The category that contributed most to blade failure was Other. If there were there no blade failures attributed to oxidation/erosion and thermal-mechanical fatigue, the overall blade L(sub 10) life would increase approximately 11 to 17 percent.

NREL: U.S. Life Cycle Inventory Database - Project Management Team

Science.gov Websites

Project Management Team Information about the U.S. Life Cycle Inventory (LCI) Database project management team is listed on this page. Additional project information is available about the U.S. LCI Mechanical Engineering, Colorado State University Professional History Michael has worked as a Senior

Computerized systems analysis and optimization of aircraft engine performance, weight, and life cycle costs

NASA Technical Reports Server (NTRS)

Fishbach, L. H.

1979-01-01

The computational techniques utilized to determine the optimum propulsion systems for future aircraft applications and to identify system tradeoffs and technology requirements are described. The characteristics and use of the following computer codes are discussed: (1) NNEP - a very general cycle analysis code that can assemble an arbitrary matrix fans, turbines, ducts, shafts, etc., into a complete gas turbine engine and compute on- and off-design thermodynamic performance; (2) WATE - a preliminary design procedure for calculating engine weight using the component characteristics determined by NNEP; (3) POD DRG - a table look-up program to calculate wave and friction drag of nacelles; (4) LIFCYC - a computer code developed to calculate life cycle costs of engines based on the output from WATE; and (5) INSTAL - a computer code developed to calculate installation effects, inlet performance and inlet weight. Examples are given to illustrate how these computer techniques can be applied to analyze and optimize propulsion system fuel consumption, weight, and cost for representative types of aircraft and missions.

A review of findings of a study of rocket based combined cycle engines applied to extensively axisymmetric single stage to orbit vehicles

NASA Technical Reports Server (NTRS)

Foster, Richard W.

1992-01-01

Extensively axisymmetric and non-axisymmetric Single Stage To Orbit (SSTO) vehicles are considered. The information is presented in viewgraph form and the following topics are presented: payload comparisons; payload as a percent of dry weight - a system hardware cost indicator; life cycle cost estimations; operations and support costs estimation; selected engine type; and rocket engine specific impulse calculation.

Conceptional Considerations to Energy Balance and Global Warming Potential of Soil Bioengineering Structures

NASA Astrophysics Data System (ADS)

von der Thannen, Magdalena; Paratscha, Roman; Smutny, Roman; Lampalzer, Thomas; Strauss, Alfred; Rauch, Hans Peter

2016-04-01

Nowadays there is a high demand on engineering solutions considering not only technical aspects but also ecological and aesthetic values. In this context soil bioengineering techniques are often used as standalone solutions or in combination with conventional engineering structures. It is a construction technique that uses biological components for hydraulic and civil engineering solutions. In general it pursues the same objectives as conventional civil engineering structures. Currently the used assessment methods for soil bioengineering structures are referencing technically, ecologically and socio-economically. In a modern engineering approach additionally, environmental impacts and potential added values should be considered. The research project E-Protect aims at developing Environmental Life Cycle Assessment (LCA) models for this special field of alpine protective constructions. Both, the Cumulative Energy Demand (CED) and the Global Warming Potential (GWP) should be considered in an Environmental LCA over the whole life cycle of an engineering structure. The life cycle itself can be divided into three phases: the construction phase, the use phase and the end of life phase. The paper represents a concept to apply an Environmental LCA model for soil bioengineering structures. Beside the construction phase of these structures particular attention will be given to the use phase. It is not only important in terms of engineering effects but also plays an important role for positive carbon footprint due to the growing plants of soil bioengineering structures in contrast to conventional structures. Innovative Environmental LCA models will be applied to soil bioengineering structures which provide a new transparency for the responsible planners and stakeholders, by pointing out the total consumption of resources in all construction phases and components.

Generation of Finite Life Distributional Goodman Diagrams for Reliability Prediction

NASA Technical Reports Server (NTRS)

Kececioglu, D.; Guerrieri, W. N.

1971-01-01

The methodology of developing finite life distributional Goodman diagrams and surfaces is described for presenting allowable combinations of alternating stress and mean stress to the design engineer. The combined stress condition is that of an alternating bending stress and a constant shear stress. The finite life Goodman diagrams and surfaces are created from strength distributions developed at various ratios of alternating to mean stress at particular cycle life values. The conclusions indicate that the Von Mises-Hencky ellipse, for cycle life values above 1000 cycles, is an adequate model of the finite life Goodman diagram. In addition, suggestions are made which reduce the number of experimental data points required in a fatigue data acquisition program.

Data-Mining Toolset Developed for Determining Turbine Engine Part Life Consumption

NASA Technical Reports Server (NTRS)

Litt, Jonathan S.

2003-01-01

The current practice in aerospace turbine engine maintenance is to remove components defined as life-limited parts after a fixed time, on the basis of a predetermined number of flight cycles. Under this schedule-based maintenance practice, the worst-case usage scenario is used to determine the usable life of the component. As shown, this practice often requires removing a part before its useful life is fully consumed, thus leading to higher maintenance cost. To address this issue, the NASA Glenn Research Center, in a collaborative effort with Pratt & Whitney, has developed a generic modular toolset that uses data-mining technology to parameterize life usage models for maintenance purposes. The toolset enables a "condition-based" maintenance approach, where parts are removed on the basis of the cumulative history of the severity of operation they have experienced. The toolset uses data-mining technology to tune life-consumption models on the basis of operating and maintenance histories. The flight operating conditions, represented by measured variables within the engine, are correlated with repair records for the engines, generating a relationship between the operating condition of the part and its service life. As shown, with the condition-based maintenance approach, the lifelimited part is in service until its usable life is fully consumed. This approach will lower maintenance costs while maintaining the safety of the propulsion system. The toolset is a modular program that is easily customizable by users. First, appropriate parametric damage accumulation models, which will be functions of engine variables, must be defined. The tool then optimizes the models to match the historical data by computing an effective-cycle metric that reduces the unexplained variability in component life due to each damage mode by accounting for the variability in operational severity. The damage increment due to operating conditions experienced during each flight is used to compute the effective cycles and ultimately the replacement time. Utilities to handle data problems, such as gaps in the flight data records, are included in the toolset. The tool was demonstrated using the first stage, high-pressure turbine blade of the PW4077 engine (Pratt & Whitney, East Hartford, CT). The damage modes considered were thermomechanical fatigue and oxidation/erosion. Each PW4077 engine contains 82 first-stage, high-pressure turbine blades, and data from a fleet of engines were used to tune the life-consumption models. The models took into account not only measured variables within the engine, but also unmeasured variables such as engine health parameters that are affected by degradation of the engine due to aging. The tool proved effective at predicting the average number of blades scrapped over time due to each damage mode, per engine, given the operating history of the engine. The customizable tools are available to interested parties within the aerospace community.

Software Program: Software Management Guidebook

NASA Technical Reports Server (NTRS)

1996-01-01

The purpose of this NASA Software Management Guidebook is twofold. First, this document defines the core products and activities required of NASA software projects. It defines life-cycle models and activity-related methods but acknowledges that no single life-cycle model is appropriate for all NASA software projects. It also acknowledges that the appropriate method for accomplishing a required activity depends on characteristics of the software project. Second, this guidebook provides specific guidance to software project managers and team leaders in selecting appropriate life cycles and methods to develop a tailored plan for a software engineering project.

Low-cycle fatigue analysis of a cooled copper combustion chamber

NASA Technical Reports Server (NTRS)

Miller, R. W.

1974-01-01

A three-dimensional finite element elastoplastic strain analysis was performed for the throat section of regeneratively cooled rocket engine combustion chamber. The analysis included thermal and pressure loads, and the effects of temperature dependent material properties, to determine the strain range corresponding to the engine operating cycle. The strain range was used in conjunction with OFHC copper isothermal fatigue test data to predict engine low-cycle fatigue life. The analysis was performed for chamber configuration and operating conditions corresponding to a hydrogen-oxygen chamber which was fatigue tested to failure at the NASA Lewis Research Center.

Merits of full flow vs. conventional staged combustion cycles for reusable launch vehicle propulsion

NASA Astrophysics Data System (ADS)

Peery, Steven D.; Parsley, Randy C.

1996-03-01

This paper provides a comparison between full-flow and conventional staged combustion thermodynamic O2/H2 rocket engine cycles for Reusable Launch Vehicle, RLV, single-stage-to-orbit applications. The impact of the cycle thermodynamics, component configuration, and component operating parameters on engine performance and weight for the two approaches is presented. Both cycles were modeled with equivalent technology turbomachinery and chamber/nozzle RLV life requirements. The first order impact of cycle selection, pump exit pressure, and turbine temperature on the empty weight of an SSTO Reusable Launch Vehicle is presented.

Chronic Sublethal Effects of San Francisco Bay Sediments on Nereis (Neanthes) arenaceodentata; Full Life-Cycle Exposure to Bedded Sediments

DTIC Science & Technology

1993-06-01

COMMUNITY ENZYME OSMOREGULATION ENERGY FLOW DNA/RNA BEHAVIOR NUTRIENT CYCLING END POINT MEMBRANES METABOLISM INTRASPECIFIC HISTOPATHOLOGY SURVIVAL...Miscellaneous Paper D-93-2AD-A268 207 June 1993 US Army Corps of Engineers Waterways Experiment Station Long-Term Effects of Dredging Operations...Program Chronic Sublethal Effects of San Francisco Bay Sediments on Nereis (Neanthes) arenaceodentata; Full Life-Cycle Exposure to Bedded Sediments by

Overview of the National Timber Bridge Inspection Study

Treesearch

James P. Wacker; Brian K. Brashaw; Frank Jalinoos

2013-01-01

As many engineers begin to implement life cycle cost analyses within the preliminary bridge design phase, there is a significant need for more reliable data on the expected service life of highway bridges. Many claims are being made about the expected longevity of concrete and steel bridges, but few are based on actual performance data. Because engineers are least...

Main propulsion system design recommendations for an advanced Orbit Transfer Vehicle

NASA Technical Reports Server (NTRS)

Redd, L.

1985-01-01

Various main propulsion system configurations of an advanced OTV are evaluated with respect to the probability of nonindependent failures, i.e., engine failures that disable the entire main propulsion system. Analysis of the life-cycle cost (LCC) indicates that LCC is sensitive to the main propulsion system reliability, vehicle dry weight, and propellant cost; it is relatively insensitive to the number of missions/overhaul, failures per mission, and EVA and IVA cost. In conclusion, two or three engines are recommended in view of their highest reliability, minimum life-cycle cost, and fail operational/fail safe capability.

The Lived Experiences of Professional Engineers over the Life-Cycle of a Technological Device

ERIC Educational Resources Information Center

Gandara, Guillermo F.

2012-01-01

One of the goals of this study was to pose the engineering role in a way that allows engineers to understand the impact that professional requirements have on their career. For engineers making medical devices, requirements come from three principal sources, professional engineering, regulatory agencies, and their own organization. Engineering…

Software Engineering Guidebook

NASA Technical Reports Server (NTRS)

Connell, John; Wenneson, Greg

1993-01-01

The Software Engineering Guidebook describes SEPG (Software Engineering Process Group) supported processes and techniques for engineering quality software in NASA environments. Three process models are supported: structured, object-oriented, and evolutionary rapid-prototyping. The guidebook covers software life-cycles, engineering, assurance, and configuration management. The guidebook is written for managers and engineers who manage, develop, enhance, and/or maintain software under the Computer Software Services Contract.

Orbit Transfer Vehicle (OTV) advanced expander cycle engine point design study, volume 2

NASA Technical Reports Server (NTRS)

1981-01-01

The engine requirements are emphasized and include: high specific impulse within a restricted installed length constraint, long life, multiple starts, different thrust levels, and man-rated reliability. The engine operating characteristics and the major component analytical design are summarized.

A Strategy for Improved System Assurance

DTIC Science & Technology

2007-06-20

Quality (Measurements Life Cycle Safety, Security & Others) ISO /IEC 12207 * Software Life Cycle Processes ISO 9001 Quality Management System...14598 Software Product Evaluation Related ISO /IEC 90003 Guidelines for the Application of ISO 9001:2000 to Computer Software IEEE 12207 Industry...Implementation of International Standard ISO /IEC 12207 IEEE 1220 Standard for Application and Management of the System Engineering Process Use in

LIFE CYCLE ENGINEERING GUIDELINES

EPA Science Inventory

This document provides guidelines for the implementation of LCE concepts, information, and techniques in engineering products, systems, processes, and facilities. To make this document as practical and useable as possible, a unifying LCE framework is presented. Subsequent topics ...

Computerized systems analysis and optimization of aircraft engine performance, weight, and life cycle costs

NASA Technical Reports Server (NTRS)

Fishbach, L. H.

1980-01-01

The computational techniques are described which are utilized at Lewis Research Center to determine the optimum propulsion systems for future aircraft applications and to identify system tradeoffs and technology requirements. Cycle performance, and engine weight can be calculated along with costs and installation effects as opposed to fuel consumption alone. Almost any conceivable turbine engine cycle can be studied. These computer codes are: NNEP, WATE, LIFCYC, INSTAL, and POD DRG. Examples are given to illustrate how these computer techniques can be applied to analyze and optimize propulsion system fuel consumption, weight and cost for representative types of aircraft and missions.

Feasibility of water injection into the turbine coolant to permit gas turbine contingency power for helicopter application

NASA Technical Reports Server (NTRS)

Vanfossen, G. J.

1983-01-01

A system which would allow a substantially increased output from a turboshaft engine for brief periods in emergency situations with little or no loss of turbine stress rupture life is proposed and studied analytically. The increased engine output is obtained by overtemperaturing the turbine; however, the temperature of the compressor bleed air used for hot section cooling is lowered by injecting and evaporating water. This decrease in cooling air temperature can offset the effect of increased gas temperature and increased shaft speed and thus keep turbine blade stress rupture life constant. The analysis utilized the NASA-Navy-Engine-Program or NNEP computer code to model the turboshaft engine in both design and off-design modes. This report is concerned with the effect of the proposed method of power augmentation on the engine cycle and turbine components. A simple cycle turboshaft engine with a 16:1 pressure ratio and a 1533 K (2760 R) turbine inlet temperature operating at sea level static conditions was studied to determine the possible power increase and the effect on turbine stress rupture life that could be expected using the proposed emergency cooling scheme. The analysis showed a 54 percent increse in output power can be achieved with no loss in gas generator turbine stress rupture life. A 231 K (415 F) rise in turbine inlet temperature is required for this level of augmentation. The required water flow rate was found to be .0109 kg water per kg of engine air flow.

A 10,000-hr life test of an engineering model resistojet

NASA Technical Reports Server (NTRS)

Slutz, Rodger J.

1990-01-01

One of the major issues associated with using resistojet thrusters on Space Station Freedom is the long life required. An engineering model resistojet was life-tested to determine if it was capable of meeting that requirement. This thruster, which was designed for 10,000 hr of operation at 2552.4 F (1400 C) or less under cyclical thermal conditions, successfully operated for 10,036 hr at 1836 F (1002 C) while undergoing 141 thermal cycles.

Initial experiments with a laser driven Stirling engine

NASA Technical Reports Server (NTRS)

Byer, R. L.

1976-01-01

Operation of a Beale free piston Stirling engine with a 40-W CO2 laser is described. Advantages of such a system include: closed-cycle operation, long life, inexpensive construction, and size scalability to 100 MW.

Space Station Freedom - Configuration management approach to supporting concurrent engineering and total quality management. [for NASA Space Station Freedom Program

NASA Technical Reports Server (NTRS)

Gavert, Raymond B.

1990-01-01

Some experiences of NASA configuration management in providing concurrent engineering support to the Space Station Freedom program for the achievement of life cycle benefits and total quality are discussed. Three change decision experiences involving tracing requirements and automated information systems of the electrical power system are described. The potential benefits of concurrent engineering and total quality management include improved operational effectiveness, reduced logistics and support requirements, prevention of schedule slippages, and life cycle cost savings. It is shown how configuration management can influence the benefits attained through disciplined approaches and innovations that compel consideration of all the technical elements of engineering and quality factors that apply to the program development, transition to operations and in operations. Configuration management experiences involving the Space Station program's tiered management structure, the work package contractors, international partners, and the participating NASA centers are discussed.

Computational Infrastructure for Engine Structural Performance Simulation

NASA Technical Reports Server (NTRS)

Chamis, Christos C.

1997-01-01

Select computer codes developed over the years to simulate specific aspects of engine structures are described. These codes include blade impact integrated multidisciplinary analysis and optimization, progressive structural fracture, quantification of uncertainties for structural reliability and risk, benefits estimation of new technology insertion and hierarchical simulation of engine structures made from metal matrix and ceramic matrix composites. Collectively these codes constitute a unique infrastructure readiness to credibly evaluate new and future engine structural concepts throughout the development cycle from initial concept, to design and fabrication, to service performance and maintenance and repairs, and to retirement for cause and even to possible recycling. Stated differently, they provide 'virtual' concurrent engineering for engine structures total-life-cycle-cost.

Specialty and Systems Engineering Supplement to IEEE 15288.1

DTIC Science & Technology

2017-08-28

requirements with a space-specific recommended practice. (8) Added Section 3.2.21, Systems Engineering Data Item Descriptions (DIDs...Systems Engineering Data Item Descriptions ........................................................ 17 4. Applicable Documents...and life cycle cost analyses. d. Alternative designs and capabilities of manufacturing are evaluated . e. Long-lead-time items, material source

Challenges of Enterprise Wide AM for Air Force Sustainment

DTIC Science & Technology

2016-12-01

December 2016 Naguy is chief of the Air Force Life Cycle Management Center’s Product Support Engineering Division at Wright Patterson Air Force Base in...today and into the future. To truly capitalize on the full potential of AM, the Air Force Life Cycle Management Center (AFLCMC) in close collabora...approach for material standards and quality include un- derstanding powder characteristics, developing an enterprise material characterization

Rebecca Hanes | NREL

Science.gov Websites

cycle inventories Economic and environmentally extended input-output analysis Sustainable design and models for sustainable design and optimization of processes, supply chains and life cycles Interactions engineering design and assessment." Doctoral dissertation, The Ohio State University, 2015. Hanes

Parametric sensitivity study for solar-assisted heat-pump systems

NASA Astrophysics Data System (ADS)

White, N. M.; Morehouse, J. H.

1981-07-01

The engineering and economic parameters affecting life-cycle costs for solar-assisted heat pump systems are investigted. The change in energy usage resulting from each engineering parameter varied was developed from computer simulations, and is compared with results from a stand-alone heat pump system. Three geographical locations are considered: Washington, DC, Fort Worth, TX, and Madison, WI. Results indicate that most engineering changes to the systems studied do not provide significant energy savings. The most promising parameters to ary are the solar collector parameters tau (-) and U/sub L/ the heat pump capacity at design point, and the minimum utilizable evaporator temperature. Costs associated with each change are estimated, and life-cycle costs computed for both engineering parameters and economic variations in interest rate, discount rate, tax credits, fuel unit costs and fuel inflation rates. Results indicate that none of the feasibile engineering changes for the system configuration studied will make these systems economically competitive with the stand-alone heat pump without a considerable tax credit.

Engineering problems in ensuring the strength and reliability of the new generation of aircraft engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boguslaev, V.A.

1995-11-01

The {open_quotes}Motor Sich{close_quotes} plant - formerly the Zaporozh`e Engine Plant - has been a major contributor to the genesis and development of the domestic aviation industry. More than 20,000 engines made at the plant are currently operating in 18 domestic models of airplanes and helicopters, while roughly 4000 of the factory`s engines are in use abroad. Also, 998 mobile gas-turbine power plants of the PAES-2500 type are presently in service in and outside the CIS. Successes such as these are the result of the tremendous effort put forth by plant personnel and close collaboration with aircraft designers and buyers andmore » scientific-research institutes on engine manufacture, operation, and servicing. Their contributions have made it possible to improve the strength and reliability of engines AI-20, AI-241 AI-25, AI-25TL, and TVZ-117. These models are renowned most of all for their durability, surpassing comparable foreign makes with respect to length of service. Engines AI-20, AI-24, and AI-25 have an average service life of 200,000 h, versus the 50,000 h life of foreign counterparts {open_quotes}Tyne,{close_quotes} {open_quotes}Dart,{close_quotes} and TE.731. At present, engine model D-18T is still not the equal of comparable foreign-made engines in terms of reliability and service life. This can be attributed to both to the problems associated with designing high-thrust engines and to the lack of adequate diagnostic systems. After several problems are resolved, new-generation engines D-36, D-136, and D-18 will provide new levels of reliability and durability. The durability of the D-36 is presently limited by the life of the casing of the combustor (6053 cycles) and the disks of the low- and high-pressure compressors (6500-7000 cycles). The life of the D-18T is restricted mainly by the life of the rotor blades in the high-pressure turbine, defects in the disks of the high-pressure compressor, and other problems.« less

Software engineering standards and practices

NASA Technical Reports Server (NTRS)

Durachka, R. W.

1981-01-01

Guidelines are presented for the preparation of a software development plan. The various phases of a software development project are discussed throughout its life cycle including a general description of the software engineering standards and practices to be followed during each phase.

Air Force Space Command. Space and Missile Systems Center Standard. Configuration Management

DTIC Science & Technology

2008-06-13

Aerospace Corporation report number TOR-2006( 8583 )-1. 3. Beneficial comments (recommendations, additions, deletions) and any pertinent data that...Engineering Drawing Practices IEEE STD 610.12 Glossary of Software Engineering Terminology, September 28,1990 ISO /IEC 12207 Software Life...item, regardless of media, formally designated and fixed at a specific time during the configuration item’s life cycle. (Source: ISO /IEC 12207

A life-cycle comparison of alternative automobile fuels.

PubMed

MacLean, H L; Lave, L B; Lankey, R; Joshi, S

2000-10-01

We examine the life cycles of gasoline, diesel, compressed natural gas (CNG), and ethanol (C2H5OH)-fueled internal combustion engine (ICE) automobiles. Port and direct injection and spark and compression ignition engines are examined. We investigate diesel fuel from both petroleum and biosources as well as C2H5OH from corn, herbaceous bio-mass, and woody biomass. The baseline vehicle is a gasoline-fueled 1998 Ford Taurus. We optimize the other fuel/powertrain combinations for each specific fuel as a part of making the vehicles comparable to the baseline in terms of range, emissions level, and vehicle lifetime. Life-cycle calculations are done using the economic input-output life-cycle analysis (EIO-LCA) software; fuel cycles and vehicle end-of-life stages are based on published model results. We find that recent advances in gasoline vehicles, the low petroleum price, and the extensive gasoline infrastructure make it difficult for any alternative fuel to become commercially viable. The most attractive alternative fuel is compressed natural gas because it is less expensive than gasoline, has lower regulated pollutant and toxics emissions, produces less greenhouse gas (GHG) emissions, and is available in North America in large quantities. However, the bulk and weight of gas storage cylinders required for the vehicle to attain a range comparable to that of gasoline vehicles necessitates a redesign of the engine and chassis. Additional natural gas transportation and distribution infrastructure is required for large-scale use of natural gas for transportation. Diesel engines are extremely attractive in terms of energy efficiency, but expert judgment is divided on whether these engines will be able to meet strict emissions standards, even with reformulated fuel. The attractiveness of direct injection engines depends on their being able to meet strict emissions standards without losing their greater efficiency. Biofuels offer lower GHG emissions, are sustainable, and reduce the demand for imported fuels. Fuels from food sources, such as biodiesel from soybeans and C2H5OH from corn, can be attractive only if the co-products are in high demand and if the fuel production does not diminish the food supply. C2H5OH from herbaceous or woody biomass could replace the gasoline burned in the light-duty fleet while supplying electricity as a co-product. While it costs more than gasoline, bioethanol would be attractive if the price of gasoline doubled, if significant reductions in GHG emissions were required, or if fuel economy regulations for gasoline vehicles were tightened.

A Life-Cycle Comparison of Alternative Automobile Fuels.

PubMed

MacLean, Heather L; Lave, Lester B; Lankey, Rebecca; Joshi, Satish

2000-10-01

We examine the life cycles of gasoline, diesel, compressed natural gas (CNG), and ethanol (C 2 H 5 OH)-fueled internal combustion engine (ICE) automobiles. Port and direct injection and spark and compression ignition engines are examined. We investigate diesel fuel from both petroleum and biosources as well as C 2 H 5 OH from corn, herbaceous bio-mass, and woody biomass. The baseline vehicle is a gasoline-fueled 1998 Ford Taurus. We optimize the other fuel/powertrain combinations for each specific fuel as a part of making the vehicles comparable to the baseline in terms of range, emissions level, and vehicle lifetime. Life-cycle calculations are done using the economic input-output life-cycle analysis (EIO-LCA) software; fuel cycles and vehicle end-of-life stages are based on published model results. We find that recent advances in gasoline vehicles, the low petroleum price, and the extensive gasoline infrastructure make it difficult for any alternative fuel to become commercially viable. The most attractive alternative fuel is compressed natural gas because it is less expensive than gasoline, has lower regulated pollutant and toxics emissions, produces less greenhouse gas (GHG) emissions, and is available in North America in large quantities. However, the bulk and weight of gas storage cylinders required for the vehicle to attain a range comparable to that of gasoline vehicles necessitates a redesign of the engine and chassis. Additional natural gas transportation and distribution infrastructure is required for large-scale use of natural gas for transportation. Diesel engines are extremely attractive in terms of energy efficiency, but expert judgment is divided on whether these engines will be able to meet strict emissions standards, even with reformulated fuel. The attractiveness of direct injection engines depends on their being able to meet strict emissions standards without losing their greater efficiency. Biofuels offer lower GHG emissions, are sustainable, and reduce the demand for imported fuels. Fuels from food sources, such as biodiesel from soybeans and C 2 H 5 OH from corn, can be attractive only if the co-products are in high demand and if the fuel production does not diminish the food supply. C 2 H 5 OH from herbaceous or woody biomass could replace the gasoline burned in the light-duty fleet while supplying electricity as a co-product. While it costs more than gasoline, bioethanol would be attractive if the price of gasoline doubled, if significant reductions in GHG emissions were required, or if fuel economy regulations for gasoline vehicles were tightened.

Advanced fabrication techniques for hydrogen-cooled engine structures

NASA Technical Reports Server (NTRS)

Buchmann, O. A.; Arefian, V. V.; Warren, H. A.; Vuigner, A. A.; Pohlman, M. J.

1985-01-01

Described is a program for development of coolant passage geometries, material systems, and joining processes that will produce long-life hydrogen-cooled structures for scramjet applications. Tests were performed to establish basic material properties, and samples constructed and evaluated to substantiate fabrication processes and inspection techniques. Results of the study show that the basic goal of increasing the life of hydrogen-cooled structures two orders of magnitude relative to that of the Hypersonic Research Engine can be reached with available means. Estimated life is 19000 cycles for the channels and 16000 cycles for pin-fin coolant passage configurations using Nickel 201. Additional research is required to establish the fatigue characteristics of dissimilar-metal coolant passages (Nickel 201/Inconel 718) and to investigate the embrittling effects of the hydrogen coolant.

Technology development life cycle processes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beck, David Franklin

2013-05-01

This report and set of appendices are a collection of memoranda originally drafted in 2009 for the purpose of providing motivation and the necessary background material to support the definition and integration of engineering and management processes related to technology development. At the time there was interest and support to move from Capability Maturity Model Integration (CMMI) Level One (ad hoc processes) to Level Three. As presented herein, the material begins with a survey of open literature perspectives on technology development life cycles, including published data on %E2%80%9Cwhat went wrong.%E2%80%9D The main thrust of the material presents a rational expose%CC%81more » of a structured technology development life cycle that uses the scientific method as a framework, with further rigor added from adapting relevant portions of the systems engineering process. The material concludes with a discussion on the use of multiple measures to assess technology maturity, including consideration of the viewpoint of potential users.« less

NASA System Engineering Design Process

NASA Technical Reports Server (NTRS)

Roman, Jose

2011-01-01

This slide presentation reviews NASA's use of systems engineering for the complete life cycle of a project. Systems engineering is a methodical, disciplined approach for the design, realization, technical management, operations, and retirement of a system. Each phase of a NASA project is terminated with a Key decision point (KDP), which is supported by major reviews.

Theory of Technical Systems--Educational Tool for Engineering

ERIC Educational Resources Information Center

Eder, Wolfgang Ernst

2016-01-01

Hubka's theory of technical systems (TTS) is briefly outlined. It describes commonalities in all engineering devices, whatever their physical principles of action. This theory is based on a general transformation system (TrfS), which can be used to show engineering in the contexts of society, economics and historic developments. The life cycle of…

Economic aspects of advanced coal-fired gas turbine locomotives

NASA Technical Reports Server (NTRS)

Liddle, S. G.; Bonzo, B. B.; Houser, B. C.

1983-01-01

Increases in the price of such conventional fuels as Diesel No. 2, as well as advancements in turbine technology, have prompted the present economic assessment of coal-fired gas turbine locomotive engines. A regenerative open cycle internal combustion gas turbine engine may be used, given the development of ceramic hot section components. Otherwise, an external combustion gas turbine engine appears attractive, since although its thermal efficiency is lower than that of a Diesel engine, its fuel is far less expensive. Attention is given to such a powerplant which will use a fluidized bed coal combustor. A life cycle cost analysis yields figures that are approximately half those typical of present locomotive engines.

Cradle-To-Gate Life Cycle Assessment of North American Hardboard and Engineered Wood Siding and Trim Production

Treesearch

Maureen Puettmann; Richard Bergman; Elaine Oneil

2016-01-01

CORRIM, the Consortium for Research on Renewable Industrial Materials (www.corrim.org), has derived life-cycle inventory (LCI) data for nine major wood products and four wood production regions in the United States (US). The LCI data cover forest regeneration through to final product at the mill gate. CORRIM’s LCI studies have included both structural and nonstructural...

Life cycle inventory energy consumption and emissions for biodiesel versus petroleum diesel fueled construction vehicles.

PubMed

Pang, Shih-Hao; Frey, H Christopher; Rasdorf, William J

2009-08-15

Substitution of soy-based biodiesel fuels for petroleum diesel will alter life cycle emissions for construction vehicles. A life cycle inventory was used to estimate fuel cycle energy consumption and emissions of selected pollutants and greenhouse gases. Real-world measurements using a portable emission measurement system (PEMS) were made forfive backhoes, four front-end loaders, and six motor graders on both fuels from which fuel consumption and tailpipe emission factors of CO, HC, NO(x), and PM were estimated. Life cycle fossil energy reductions are estimated it 9% for B20 and 42% for B100 versus petroleum diesel based on the current national energy mix. Fuel cycle emissions will contribute a larger share of total life cycle emissions as new engines enter the in-use fleet. The average differences in life cycle emissions for B20 versus diesel are: 3.5% higher for NO(x); 11.8% lower for PM, 1.6% higher for HC, and 4.1% lower for CO. Local urban tailpipe emissions are estimated to be 24% lower for HC, 20% lower for CO, 17% lower for PM, and 0.9% lower for NO(x). Thus, there are environmental trade-offs such as for rural vs urban areas. The key sources of uncertainty in the B20 LCI are vehicle emission factors.

Sign Life-Cycle Policies and Practices : Transportation Research Synthesis

DOT National Transportation Integrated Search

2017-10-01

MnDOT Metro District Traffic Engineering is interested in the practices that other state departments of transportation (DOTs) use to determine traffic sign life expectancy and replacement. Of particular interest is the state of the practice regarding...

The reliability-quality relationship for quality systems and quality risk management.

PubMed

Claycamp, H Gregg; Rahaman, Faiad; Urban, Jason M

2012-01-01

Engineering reliability typically refers to the probability that a system, or any of its components, will perform a required function for a stated period of time and under specified operating conditions. As such, reliability is inextricably linked with time-dependent quality concepts, such as maintaining a state of control and predicting the chances of losses from failures for quality risk management. Two popular current good manufacturing practice (cGMP) and quality risk management tools, failure mode and effects analysis (FMEA) and root cause analysis (RCA) are examples of engineering reliability evaluations that link reliability with quality and risk. Current concepts in pharmaceutical quality and quality management systems call for more predictive systems for maintaining quality; yet, the current pharmaceutical manufacturing literature and guidelines are curiously silent on engineering quality. This commentary discusses the meaning of engineering reliability while linking the concept to quality systems and quality risk management. The essay also discusses the difference between engineering reliability and statistical (assay) reliability. The assurance of quality in a pharmaceutical product is no longer measured only "after the fact" of manufacturing. Rather, concepts of quality systems and quality risk management call for designing quality assurance into all stages of the pharmaceutical product life cycle. Interestingly, most assays for quality are essentially static and inform product quality over the life cycle only by being repeated over time. Engineering process reliability is the fundamental concept that is meant to anticipate quality failures over the life cycle of the product. Reliability is a well-developed theory and practice for other types of manufactured products and manufacturing processes. Thus, it is well known to be an appropriate index of manufactured product quality. This essay discusses the meaning of reliability and its linkages with quality systems and quality risk management.

RDD-100 and the systems engineering process

NASA Technical Reports Server (NTRS)

Averill, Robert D.

1994-01-01

An effective systems engineering approach applied through the project life cycle can help Langley produce a better product. This paper demonstrates how an enhanced systems engineering process for in-house flight projects assures that each system will achieve its goals with quality performance and within planned budgets and schedules. This paper also describes how the systems engineering process can be used in combination with available software tools.

Integrated computational materials engineering: Tools, simulations and new applications

DOE PAGES

Madison, Jonathan D.

2016-03-30

Here, Integrated Computational Materials Engineering (ICME) is a relatively new methodology full of tremendous potential to revolutionize how science, engineering and manufacturing work together. ICME was motivated by the desire to derive greater understanding throughout each portion of the development life cycle of materials, while simultaneously reducing the time between discovery to implementation [1,2].

ESD/MITRE Software Acquisition Symposium Proceedings; an ESD/Industry Dialogue held in Bedford, Massachusetts on May 6-7, 1986

DTIC Science & Technology

1986-05-07

Cycle? Moderator: Christine M. Anderson Dennis D. Doe Manager of Engineering Software and Artificial Intelligence Boeing Aerospace Company In... intelligence systems development pro- cess affect the life cycle? Artificial intelligence developers seem to be the last haven for people who don’t...of Engineering Software and Artificial Intelligence at the Boeing Aerospace Company. In this capacity, Mr. Doe is the focal point for software

Executive overview and introduction to the SMAP information system life-cycle and documentation standards

NASA Technical Reports Server (NTRS)

1989-01-01

An overview of the five volume set of Information System Life-Cycle and Documentation Standards is provided with information on its use. The overview covers description, objectives, key definitions, structure and application of the standards, and document structure decisions. These standards were created to provide consistent NASA-wide structures for coordinating, controlling, and documenting the engineering of an information system (hardware, software, and operational procedures components) phase by phase.

Recommended approach to software development, revision 3

NASA Technical Reports Server (NTRS)

Landis, Linda; Waligora, Sharon; Mcgarry, Frank; Pajerski, Rose; Stark, Mike; Johnson, Kevin Orlin; Cover, Donna

1992-01-01

Guidelines for an organized, disciplined approach to software development that is based on studies conducted by the Software Engineering Laboratory (SEL) since 1976 are presented. It describes methods and practices for each phase of a software development life cycle that starts with requirements definition and ends with acceptance testing. For each defined life cycle phase, guidelines for the development process and its management, and for the products produced and their reviews are presented.

Study of turbine bypass remote augmentor lift system for V/STOL aircraft

NASA Technical Reports Server (NTRS)

Sheridan, A. E.

1985-01-01

The airframe design and engine/aircraft integration were emphasized in a NASA comparative study of turbofan and turbine bypass engine (TBE) with remote augmentor lift systems (RALS) for supersonic V/STOL aircraft. Functional features of the TBE are reviewed, noting the enhanced cycle efficiency and reduced afterbody drag compared to the turbojets. The present studies examied performance levels for aircraft with fleet defense and secondary anti-surface warfare roles, carrying AMRAAM and AIM missiles. TBE engine cycles were configured for hover and up-and-away flight from deck launch, and all tests were done from a conceptual design viewpoint. The results indicate that the TBE-RALS is superior to turbofan-RALS aircraft in both gross take-off weight and life cycle cost.

Calculation of the Thermal Loading of the Cylinder-Piston Group of the Automobile Engine

NASA Astrophysics Data System (ADS)

Barchenko, F. B.; Bakulin, V. N.

2017-05-01

We propose a mathematical model for calculating thermal loods of parts of the cylinder-piston group of the automobile engine operating under unstable conditions in its complete life cycle. Methods have been described for calculating the boundary conditions to determine the thermal state of the parts of the cylinder-piston group of such an engine with the use of theoretical formulas, empirical and semiempirical relations, and tabulated data. In modeling, we calculated the work of all systems of the engine (pumps, pipelines, heat exchangers) influencing directly or indirectly the thermal state of its cylinder-piston group. The nonstationary thermal state was calculated once in the operating cycle of the engine with the use of the cycle-averaged values of the local heat transfer coefficients and the resulting temperature of the medium. The personal computer counting time for one time step of a transport diesel engine of typical design with a number of units of the order of 500 was 5 s.

Stand-alone flat-plate photovoltaic power systems: System sizing and life-cycle costing methodology for Federal agencies

NASA Technical Reports Server (NTRS)

Borden, C. S.; Volkmer, K.; Cochrane, E. H.; Lawson, A. C.

1984-01-01

A simple methodology to estimate photovoltaic system size and life-cycle costs in stand-alone applications is presented. It is designed to assist engineers at Government agencies in determining the feasibility of using small stand-alone photovoltaic systems to supply ac or dc power to the load. Photovoltaic system design considerations are presented as well as the equations for sizing the flat-plate array and the battery storage to meet the required load. Cost effectiveness of a candidate photovoltaic system is based on comparison with the life-cycle cost of alternative systems. Examples of alternative systems addressed are batteries, diesel generators, the utility grid, and other renewable energy systems.

Successful completion of a cyclic ground test of a mercury ion auxiliary propulsion system

NASA Technical Reports Server (NTRS)

Francisco, David R.; Low, Charles A., Jr.; Power, John L.

1988-01-01

An engineering model Ion Auxiliary Propulsion System (IAPS) 8-cm thruster (S/N 905) has completed a life test at NASA Lewis Research Center. The mercury ion thruster successfully completed and exceeded the test goals of 2557 on/off cycles and 7057 hr of operation at full thrust. The final 1200 cycles and 3600 hr of the life test were conducted using an engineering model of the IAPS power electronics unit (PEU) and breadboard digital controller and interface unit (DCIU). This portion of the test is described in this paper with a charted history of thruster operating parameters and off-normal events. Performance and operating characteristics were constant throughout the test with only minor variations. The engineering model power electronics unit operated without malfunction; the flight software in the digital controller and interface unit was exercised and verified. Post-test inspection of the thruster revealed facility enhanced accelerator grid erosion but overall the thruster was in good condition. It was concluded that the thruster performance was not drastically degraded by time or cycles. Additional cyclic testing is currently under consideration.

Successful completion of a cyclic ground test of a mercury Ion Auxiliary Propulsion System

NASA Technical Reports Server (NTRS)

Francisco, David R.; Low, Charles A., Jr.; Power, John L.

1988-01-01

An engineering model Ion Auxiliary Propulsion System (IAPS) 8-cm thruster (S/N 905) has completed a life test at NASA Lewis Research Center. The mercury ion thruster successfully completed and exceeded the test goals of 2557 on/off cycles and 7057 hr of operation at full thrust. The final 1200 cycles and 3600 hr of the life test were conducted using an engineering model of the IAPS power electronics unit (PEU) and breadboard digital controller and interface unit (DCIU). This portion of the test is described in this paper with a charted history of thruster operating parameters and off-normal events. Performance and operating characteristics were constant throughout the test with only minor variations. The engineering model power electronics unit operated without malfunction; the flight software in the digital controller and interface unit was exercised and verified. Post-test inspection of the thruster revealed facility enhanced accelerator grid erosion but overall the thruster was in good condition. It was concluded that the thruster performance was not drastically degraded by time or cycles. Additional cyclic testing is currently under consideration.

Aerospace Systems Design in NASA's Collaborative Engineering Environment

NASA Technical Reports Server (NTRS)

Monell, Donald W.; Piland, William M.

2000-01-01

Past designs of complex aerospace systems involved an environment consisting of collocated design teams with project managers, technical discipline experts, and other experts (e.g., manufacturing and systems operation). These experts were generally qualified only on the basis of past design experience and typically had access to a limited set of integrated analysis tools. These environments provided less than desirable design fidelity, often lead to the inability of assessing critical programmatic and technical issues (e.g., cost, risk, technical impacts), and generally derived a design that was not necessarily optimized across the entire system. The continually changing, modern aerospace industry demands systems design processes that involve the best talent available (no matter where it resides) and access to the the best design and analysis tools. A solution to these demands involves a design environment referred to as collaborative engineering. The collaborative engineering environment evolving within the National Aeronautics and Space Administration (NASA) is a capability that enables the Agency's engineering infrastructure to interact and use the best state-of-the-art tools and data across organizational boundaries. Using collaborative engineering, the collocated team is replaced with an interactive team structure where the team members are geographical distributed and the best engineering talent can be applied to the design effort regardless of physical location. In addition, a more efficient, higher quality design product is delivered by bringing together the best engineering talent with more up-to-date design and analysis tools. These tools are focused on interactive, multidisciplinary design and analysis with emphasis on the complete life cycle of the system, and they include nontraditional, integrated tools for life cycle cost estimation and risk assessment. NASA has made substantial progress during the last two years in developing a collaborative engineering environment. NASA is planning to use this collaborative engineering engineering infrastructure to provide better aerospace systems life cycle design and analysis, which includes analytical assessment of the technical and programmatic aspects of a system from "cradle to grave." This paper describes the recent NASA developments in the area of collaborative engineering, the benefits (realized and anticipated) of using the developed capability, and the long-term plans for implementing this capability across Agency.

Advanced hybrid vehicle propulsion system study

NASA Technical Reports Server (NTRS)

Schwarz, R.

1982-01-01

Results are presented of a study of an advanced heat engine/electric automotive hybrid propulsion system. The system uses a rotary stratified charge engine and ac motor/controller in a parallel hybrid configuration. The three tasks of the study were (1) parametric studies involving five different vehicle types, (2) design trade-off studies to determine the influence of various vehicle and propulsion system paramaters on system performance fuel economy and cost, and (3) a conceptual design establishing feasibility at the selected approach. Energy consumption for the selected system was .034 1/km (61.3 mpg) for the heat engine and .221 kWh/km (.356 kWh/mi) for the electric power system over a modified J227 a schedule D driving cycle. Life cycle costs were 7.13 cents/km (11.5 cents/mi) at $2/gal gasoline and 7 cents/kWh electricity for 160,000 km (100,000 mi) life.

Ada education in a software life-cycle context

NASA Technical Reports Server (NTRS)

Clough, Anne J.

1986-01-01

Some of the experience gained from a comprehensive educational program undertaken at The Charles Stark Draper Lab. to introduce the Ada language and to transition modern software engineering technology into the development of Ada and non-Ada applications is described. Initially, a core group, which included manager, engineers and programmers, received training in Ada. An Ada Office was established to assume the major responsibility for training, evaluation, acquisition and benchmarking of tools, and consultation on Ada projects. As a first step in this process, and in-house educational program was undertaken to introduce Ada to the Laboratory. Later, a software engineering course was added to the educational program as the need to address issues spanning the entire software life cycle became evident. Educational efforts to date are summarized, with an emphasis on the educational approach adopted. Finally, lessons learned in administering this program are addressed.

Aircraft Structural Design Handbook for Lower Cost Maintenance and Repair

DTIC Science & Technology

1977-03-01

Structure Repair and Maintenance program under Air Force contract F33615-74-C-3101, Project No. 1368, Task No. 136802. The work was performed by...Interchangeability 6.4.5.3 Work Area Consideration 6.5 Life Cycle Cost Impact Considerati ons 6.5.1 Introduction 6.5.2 Objective 6.5.3 Life Cycle Cost...engine sonic vibration, ^auses working of the vane assemblies and their inboard and outboard attach members resulting in fatigue cracks. The constant

Qualification of Life Extension Schemes for Engine Components (Homologation des Programmes de Prolongation du cycle de vie des Organes Moteur)

DTIC Science & Technology

1999-03-01

cycle managers include (1) improving the durability of components through material substitution, or the addition of protective coatings, (2) returning... including in service trials, is required to demonstrate that the repaired and/or modified component is safe to use and remains so once returned to...Better Turbine Materials and Technology Including 5 Predicted Life Improvements by T.J. Williams Repair Developments to Fit Customer Needs (Presented

Life-Extending Control for Aircraft Engines Studied

NASA Technical Reports Server (NTRS)

Guo, Te-Huei

2002-01-01

Current aircraft engine controllers are designed and operated to provide both performance and stability margins. However, the standard method of operation results in significant wear and tear on the engine and negatively affects the on-wing life--the time between cycles when the engine must be physically removed from the aircraft for maintenance. The NASA Glenn Research Center and its industrial and academic partners have been working together toward a new control concept that will include engine life usage as part of the control function. The resulting controller will be able to significantly extend the engine's on-wing life with little or no impact on engine performance and operability. The new controller design will utilize damage models to estimate and mitigate the rate and overall accumulation of damage to critical engine parts. The control methods will also provide a means to assess tradeoffs between performance and structural durability on the basis of mission requirements and remaining engine life. Two life-extending control methodologies were studied to reduce the overall life-cycle cost of aircraft engines. The first methodology is to modify the baseline control logic to reduce the thermomechanical fatigue (TMF) damage of cooled stators during acceleration. To accomplish this, an innovative algorithm limits the low-speed rotor acceleration command when the engine has reached a threshold close to the requested thrust. This algorithm allows a significant reduction in TMF damage with only a very small increase in the rise time to reach the commanded rotor speed. The second methodology is to reduce stress rupture/creep damage to turbine blades and uncooled stators by incorporating an engine damage model into the flight mission. Overall operation cost is reduced by an optimization among the flight time, fuel consumption, and component damages. Recent efforts have focused on applying life-extending control technology to an existing commercial turbine engine, and doing so without modifying the hardware or adding sensors. This approach makes it possible to retrofit existing engines with life-extending control technology by changing only the control software in the full-authority digital engine controller (FADEC). The significant results include demonstrating a 20- to 30-percent reduction in TMF damage to the hot section by developing and implementing smart acceleration logic during takeoff. The tradeoff is an increase, from 5.0 to 5.2 sec, in the time required to reach maximum power from ground idle. On a typical flight profile of a cruise at Mach 0.8 at an altitude of 41,000 ft, and cruise time of 104 min, the optimized system showed that a reduction in cruise speed from Mach 0.8 to 0.79 can achieve an estimated 25-to 35-percent creep/rupture damage reduction in the engine's hot section and a fuel savings of 2.1 percent. The tradeoff is an increase in flight time of 1.3 percent (1.4 min).

Energy and emissions saving potential of additive manufacturing: the case of lightweight aircraft components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Runze; Riddle, Matthew; Graziano, Diane

Additive manufacturing (AM) holds great potential for improving materials efficiency, reducing life-cycle impacts, and enabling greater engineering functionality compared to conventional manufacturing (CM), and AM has been increasingly adopted by aircraft component manufacturers for lightweight, cost-effective designs. This study estimates the net changes in life-cycle primary energy and greenhouse gas emissions associated with AM technologies for lightweight metallic aircraft components through the year 2050, to shed light on the environmental benefits of a shift from CM to AM processes in the U.S. aircraft industry. A systems modeling framework is presented, with integrates engineering criteria, life-cycle environmental data, aircraft fleet stockmore » and fuel use models under different AM adoption scenarios. Estimated fleet-wide life-cycle primary energy savings at most reach 70-173 million GJ/year in 2050, with cumulative savings of 1.2–2.8 billion GJ. Associated cumulative GHG emission reductions were estimated at 92.1–215.0 million metric tons. In addition, thousands of tons of aluminum, titanium and nickel alloys could be potentially saved per year in 2050. The results indicate a significant role of AM technologies in helping society meet its long-term energy use and GHG emissions reduction goals, and highlight barriers and opportunities for AM adoption for the aircraft industry.« less

A Structured Approach for Reviewing Architecture Documentation

DTIC Science & Technology

2009-12-01

as those found in ISO 12207 [ ISO /IEC 12207 :2008] (for software engineering), ISO 15288 [ ISO /IEC 15288:2008] (for systems engineering), the Rational...Open Distributed Processing - Reference Model: Foundations ( ISO /IEC 10746-2). 1996. [ ISO /IEC 12207 :2008] International Organization for...Standardization & International Electrotechnical Commission. Sys- tems and software engineering – Software life cycle processes ( ISO /IEC 12207 ). 2008. [ ISO

From Beginning to End: How Engineering Students Think and Talk about Sustainability across the Life Cycle. Research Brief

ERIC Educational Resources Information Center

Kilgore, Deborah; Jocuns, Andrew; Yasuhara, Ken; Atman, Cynthia J.

2009-01-01

The Academic Pathways Study (APS) is a multi-institution, mixed-methods, longitudinal study which examines engineering students' learning and development as they move into, through, and beyond their undergraduate institutions (Atman et al., 2008; Sheppard et al., 2004). It is part of the Center for the Advancement of Engineering Education…

Nonlinear Control of a Reusable Rocket Engine for Life Extension

NASA Technical Reports Server (NTRS)

Lorenzo, Carl F.; Holmes, Michael S.; Ray, Asok

1998-01-01

This paper presents the conceptual development of a life-extending control system where the objective is to achieve high performance and structural durability of the plant. A life-extending controller is designed for a reusable rocket engine via damage mitigation in both the fuel (H2) and oxidizer (O2) turbines while achieving high performance for transient responses of the combustion chamber pressure and the O2/H2 mixture ratio. The design procedure makes use of a combination of linear and nonlinear controller synthesis techniques and also allows adaptation of the life-extending controller module to augment a conventional performance controller of the rocket engine. The nonlinear aspect of the design is achieved using non-linear parameter optimization of a prescribed control structure. Fatigue damage in fuel and oxidizer turbine blades is primarily caused by stress cycling during start-up, shutdown, and transient operations of a rocket engine. Fatigue damage in the turbine blades is one of the most serious causes for engine failure.

Application of Space Environmental Observations to Spacecraft Pre-Launch Engineering and Spacecraft Operations

NASA Technical Reports Server (NTRS)

Barth, Janet L.; Xapsos, Michael

2008-01-01

This presentation focuses on the effects of the space environment on spacecraft systems and applying this knowledge to spacecraft pre-launch engineering and operations. Particle radiation, neutral gas particles, ultraviolet and x-rays, as well as micrometeoroids and orbital debris in the space environment have various effects on spacecraft systems, including degradation of microelectronic and optical components, physical damage, orbital decay, biasing of instrument readings, and system shutdowns. Space climate and weather must be considered during the mission life cycle (mission concept, mission planning, systems design, and launch and operations) to minimize and manage risk to both the spacecraft and its systems. A space environment model for use in the mission life cycle is presented.

Advanced Turbine Technology Applications Project (ATTAP)

NASA Technical Reports Server (NTRS)

1991-01-01

ATTAP activities were highlighted by test bed engine design and development activities; ceramic component design; materials and engine component characterization; ceramic component process development and fabrication; component rig testing; and test bed engine fabrication and testing. Specifically, ATTAP aims to develop and demonstrate the technology of structural ceramics that have the potential for competitive automotive engine life cycle cost and for operating for 3500 hours in a turbine engine environment at temperatures up to 1371 C (2500 F).

Aerospace Systems Design in NASA's Collaborative Engineering Environment

NASA Technical Reports Server (NTRS)

Monell, Donald W.; Piland, William M.

1999-01-01

Past designs of complex aerospace systems involved an environment consisting of collocated design teams with project managers, technical discipline experts, and other experts (e.g. manufacturing and systems operations). These experts were generally qualified only on the basis of past design experience and typically had access to a limited set of integrated analysis tools. These environments provided less than desirable design fidelity, often lead to the inability of assessing critical programmatic and technical issues (e.g., cost risk, technical impacts), and generally derived a design that was not necessarily optimized across the entire system. The continually changing, modern aerospace industry demands systems design processes that involve the best talent available (no matter where it resides) and access to the best design and analysis tools. A solution to these demands involves a design environment referred to as collaborative engineering. The collaborative engineering environment evolving within the National Aeronautics and Space Administration (NASA) is a capability that enables the Agency's engineering infrastructure to interact and use the best state-of-the-art tools and data across organizational boundaries. Using collaborative engineering, the collocated team is replaced with an interactive team structure where the team members are geographically distributed and the best engineering talent can be applied to the design effort regardless of physical location. In addition, a more efficient, higher quality design product is delivered by bringing together the best engineering talent with more up-to-date design and analysis tools. These tools are focused on interactive, multidisciplinary design and analysis with emphasis on the complete life cycle of the system, and they include nontraditional, integrated tools for life cycle cost estimation and risk assessment. NASA has made substantial progress during the last two years in developing a collaborative engineering environment. NASA is planning to use this collaborative engineering infrastructure to provide better aerospace systems life cycle design and analysis, which includes analytical assessment of the technical and programmatic aspects of a system from "cradle to grave." This paper describes the recent NASA developments in the area of collaborative engineering, the benefits (realized and anticipated) of using the developed capability, and the long-term plans for implementing this capability across the Agency.

Aerospace Systems Design in NASA's Collaborative Engineering Environment

NASA Astrophysics Data System (ADS)

Monell, Donald W.; Piland, William M.

2000-07-01

Past designs of complex aerospace systems involved an environment consisting of collocated design teams with project managers, technical discipline experts, and other experts (e.g., manufacturing and systems operations). These experts were generally qualified only on the basis of past design experience and typically had access to a limited set of integrated analysis tools. These environments provided less than desirable design fidelity, often led to the inability of assessing critical programmatic and technical issues (e.g., cost, risk, technical impacts), and generally derived a design that was not necessarily optimized across the entire system. The continually changing, modern aerospace industry demands systems design processes that involve the best talent available (no matter where it resides) and access to the best design and analysis tools. A solution to these demands involves a design environment referred to as collaborative engineering. The collaborative engineering environment evolving within the National Aeronautics and Space Administration (NASA) is a capability that enables the Agency's engineering infrastructure to interact and use the best state-of-the-art tools and data across organizational boundaries. Using collaborative engineering, the collocated team is replaced with an interactive team structure where the team members are geographically distributed and the best engineering talent can be applied to the design effort regardless of physical location. In addition, a more efficient, higher quality design product is delivered by bringing together the best engineering talent with more up-to-date design and analysis tools. These tools are focused on interactive, multidisciplinary design and analysis with emphasis on the complete life cycle of the system, and they include nontraditional, integrated tools for life cycle cost estimation and risk assessment. NASA has made substantial progress during the last two years in developing a collaborative engineering environment. NASA is planning to use this collaborative engineering infrastructure to provide better aerospace systems life cycle design and analysis, which includes analytical assessment of the technical and programmatic aspects of a system from "cradle to grave." This paper describes the recent NASA developments in the area of collaborative engineering, the benefits (realized and anticipated) of using the developed capability, and the long-term plans for implementing this capability across the Agency.

Service life assessment of timber highway bridges in USA climate zones

Treesearch

James P. Wacker; Brian K. Brashaw; Thomas G. Williamson; P. David Jones; Matthew S. Smith; Travis K. Hosteng; David L. Strahl; Lola E. Coombe; V.J. Gopu

2014-01-01

As engineers begin to estimate life-cycle costs and sustainable design approaches for timber bridges, there is a need for more reliable data about their durability and expected service life. This paper summarizes a comprehensive effort to assess the current condition of more than one hundred timber highway bridge superstructures throughout the United States. This...

Cycle Counting Methods of the Aircraft Engine

ERIC Educational Resources Information Center

Fedorchenko, Dmitrii G.; Novikov, Dmitrii K.

2016-01-01

The concept of condition-based gas turbine-powered aircraft operation is realized all over the world, which implementation requires knowledge of the end-of-life information related to components of aircraft engines in service. This research proposes an algorithm for estimating the equivalent cyclical running hours. This article provides analysis…

The construction of life prediction models for the design of Stirling engine heater components

NASA Technical Reports Server (NTRS)

Petrovich, A.; Bright, A.; Cronin, M.; Arnold, S.

1983-01-01

The service life of Stirling-engine heater structures of Fe-based high-temperature alloys is predicted using a numerical model based on a linear-damage approach and published test data (engine test data for a Co-based alloy and tensile-test results for both the Co-based and the Fe-based alloys). The operating principle of the automotive Stirling engine is reviewed; the economic and technical factors affecting the choice of heater material are surveyed; the test results are summarized in tables and graphs; the engine environment and automotive duty cycle are characterized; and the modeling procedure is explained. It is found that the statistical scatter of the fatigue properties of the heater components needs to be reduced (by decreasing the porosity of the cast material or employing wrought material in fatigue-prone locations) before the accuracy of life predictions can be improved.

Preliminary design of a supersonic Short Takeoff and Vertical Landing (STOVL) fighter aircraft

NASA Technical Reports Server (NTRS)

Cox, Brian; Borchers, Paul; Gomer, Charlie; Henderson, Dean; Jacobs, Tavis; Lawson, Todd; Peterson, Eric; Ross, Tweed, III; Bellmard, Larry

1990-01-01

The preliminary design study of a supersonic Short Takeoff and Vertical Landing (STOVL) fighter is presented. A brief historical survey of powered lift vehicles was presented, followed by a technology assessment of the latest supersonic STOVL engine cycles under consideration by industry and government in the U.S. and UK. A survey of operational fighter/attack aircraft and the modern battlefield scenario were completed to develop, respectively, the performance requirements and mission profiles for the study. Three configurations were initially investigated with the following engine cycles: a hybrid fan vectored thrust cycle, a lift+lift/cruise cycle, and a mixed flow vectored thrust cycle. The lift+lift/cruise aircraft configuration was selected for detailed design work which consisted of: (1) a material selection and structural layout, including engine removal considerations, (2) an aircraft systems layout, (3) a weapons integration model showing the internal weapons bay mechanism, (4) inlet and nozzle integration, (5) an aircraft suckdown prediction, (6) an aircraft stability and control analysis, including a takeoff, hover, and transition control analysis, (7) a performance and mission capability study, and (8) a life cycle cost analysis. A supersonic fighter aircraft with STOVL capability with the lift+lift/cruise engine cycle seems a viable option for the next generation fighter.

Comparative Human Health Impact Assessment of Engineered Nanomaterials in the Framework of Life Cycle Assessment.

PubMed

Fransman, Wouter; Buist, Harrie; Kuijpers, Eelco; Walser, Tobias; Meyer, David; Zondervan-van den Beuken, Esther; Westerhout, Joost; Klein Entink, Rinke H; Brouwer, Derk H

2017-07-01

For safe innovation, knowledge on potential human health impacts is essential. Ideally, these impacts are considered within a larger life-cycle-based context to support sustainable development of new applications and products. A methodological framework that accounts for human health impacts caused by inhalation of engineered nanomaterials (ENMs) in an indoor air environment has been previously developed. The objectives of this study are as follows: (i) evaluate the feasibility of applying the CF framework for NP exposure in the workplace based on currently available data; and (ii) supplement any resulting knowledge gaps with methods and data from the life cycle approach and human risk assessment (LICARA) project to develop a modified case-specific version of the framework that will enable near-term inclusion of NP human health impacts in life cycle assessment (LCA) using a case study involving nanoscale titanium dioxide (nanoTiO 2 ). The intent is to enhance typical LCA with elements of regulatory risk assessment, including its more detailed measure of uncertainty. The proof-of-principle demonstration of the framework highlighted the lack of available data for both the workplace emissions and human health effects of ENMs that is needed to calculate generalizable characterization factors using common human health impact assessment practices in LCA. The alternative approach of using intake fractions derived from workplace air concentration measurements and effect factors based on best-available toxicity data supported the current case-by-case approach for assessing the human health life cycle impacts of ENMs. Ultimately, the proposed framework and calculations demonstrate the potential utility of integrating elements of risk assessment with LCA for ENMs once the data are available. © 2016 Society for Risk Analysis.

Engine Seal Technology Requirements to Meet NASA's Advanced Subsonic Technology Program Goals

NASA Technical Reports Server (NTRS)

Steinetz, Bruce M.; Hendricks, Robert C.

1994-01-01

Cycle studies have shown the benefits of increasing engine pressure ratios and cycle temperatures to decrease engine weight and improve performance of commercial turbine engines. NASA is working with industry to define technology requirements of advanced engines and engine technology to meet the goals of NASA's Advanced Subsonic Technology Initiative. As engine operating conditions become more severe and customers demand lower operating costs, NASA and engine manufacturers are investigating methods of improving engine efficiency and reducing operating costs. A number of new technologies are being examined that will allow next generation engines to operate at higher pressures and temperatures. Improving seal performance - reducing leakage and increasing service life while operating under more demanding conditions - will play an important role in meeting overall program goals of reducing specific fuel consumption and ultimately reducing direct operating costs. This paper provides an overview of the Advanced Subsonic Technology program goals, discusses the motivation for advanced seal development, and highlights seal technology requirements to meet future engine performance goals.

The effect of microstructure, temperature, and hold-time on low-cycle fatigue of As HIP P/M Rene 95

NASA Technical Reports Server (NTRS)

Bashir, S.; Antolovich, S. D.

1984-01-01

The effects of microstructure, temperature, plastic strain range, and hold time on the low-cycle fatigue (LCF) life were studied for Rene 95, an important Ni base superalloy used in jet engine disks. It was shown that the life could be varied by approximately an order of magnitude at elevated temperatures by simple heat treatments. The life was largest for the microstructure that promoted the most homogeneous deformation mode. The results are explained using the concept of a synergistic interaction between the deformation mode and boundary oxidation.

System Re-engineering Project Executive Summary

DTIC Science & Technology

1991-11-01

Management Information System (STAMIS) application. This project involved reverse engineering, evaluation of structured design and object-oriented design, and re- implementation of the system in Ada. This executive summary presents the approach to re-engineering the system, the lessons learned while going through the process, and issues to be considered in future tasks of this nature.... Computer-Aided Software Engineering (CASE), Distributed Software, Ada, COBOL, Systems Analysis, Systems Design, Life Cycle Development, Functional Decomposition, Object-Oriented

Life-Cycle Cost Database. Volume II. Appendices E, F, and G. Sample Data Development.

DTIC Science & Technology

1983-01-01

Bendix Field Engineering Corporation Columbia, Maryland 21045 5 CONTENTS Page GENERAL 8 Introduction Objective Engineering Survey SYSTEM DESCRIPTION...in a typical administrative type building over a 25-year period. 1.3 ENGINEERING SURVEY An on-site survey was conducted by Bendix Field Engineering...Damp Mop and Buff Buff Routine Vacuum Strip and Refinish Heavy Duty Vacuum Machine, Scrub and Surface Shampoo Pick Up Extraction Clean Repair Location

User’s Manual for SEEK TALK Full Scale Engineering Development Life Cycle Cost (LCC) Model. Volume II. Model Equations and Model Operations.

DTIC Science & Technology

1981-04-01

LIFE CYCLE COST (LCC) LCC SENSITIVITY ANALYSIS LCC MODE , REPAIR LEVEL ANALYSIS (RLA) 20 ABSTRACT (Cnn tlnue on reverse side It necessary and Identify... level analysis capability. Next it provides values for Air Force input parameters and instructions for contractor inputs, general operating...Maintenance Manhour Requirements 39 5.1.4 Calculation of Repair Level Fractions 43 5.2 Cost Element Equations 47 5.2.1 Production Cost Element 47

Systems Engineering and Integration as a Foundation for Mission Engineering

DTIC Science & Technology

2015-09-01

parallels the INCOSE definition to develop a system, it is important to note the focus on a complete life cycle balanced solution and the satisfaction of...unacceptable to relevant stakeholders. Principle 7 Managers should acknowledge the potential conflicts between (a) their own role as corporate...engineer in understanding the relationships between various needs and to identify similarities, differences, or redundancies. Another method for

Analysis of the JSF Engine Competition

DTIC Science & Technology

2012-09-01

even 25 Competition for Support Services  Support costs are typically more than half of life-cycle costs and normally incurred in a sole-source...Strike Fighter), Aircraft Engines, Competition, Military Procurement, Defense Industry, Cost Analysis Analysis of the JSF Engine Competition James...different designs to meet the same functional requirements. Such a case was examined by the Institute for Defense Analyses in a forward-looking cost and

A probabilistic maintenance model for diesel engines

NASA Astrophysics Data System (ADS)

Pathirana, Shan; Abeygunawardane, Saranga Kumudu

2018-02-01

In this paper, a probabilistic maintenance model is developed for inspection based preventive maintenance of diesel engines based on the practical model concepts discussed in the literature. Developed model is solved using real data obtained from inspection and maintenance histories of diesel engines and experts' views. Reliability indices and costs were calculated for the present maintenance policy of diesel engines. A sensitivity analysis is conducted to observe the effect of inspection based preventive maintenance on the life cycle cost of diesel engines.

Software engineering from a Langley perspective

NASA Technical Reports Server (NTRS)

Voigt, Susan

1994-01-01

A brief introduction to software engineering is presented. The talk is divided into four sections beginning with the question 'What is software engineering', followed by a brief history of the progression of software engineering at the Langley Research Center in the context of an expanding computing environment. Several basic concepts and terms are introduced, including software development life cycles and maturity levels. Finally, comments are offered on what software engineering means for the Langley Research Center and where to find more information on the subject.

10 CFR 433.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

.... IESNA means Illuminating Engineering Society of North America. Life-cycle cost means the total cost... in support of a manufacturing, industrial, or commercial process. Process loads do not include energy...

10 CFR 433.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

.... IESNA means Illuminating Engineering Society of North America. Life-cycle cost means the total cost... in support of a manufacturing, industrial, or commercial process. Process loads do not include energy...

Strainrange partitioning behavior of an automotive turbine alloy

NASA Technical Reports Server (NTRS)

Annis, C. G.; Vanwanderham, M. C.; Wallace, R. M.

1976-01-01

This report addresses Strainrange Partitioning, an advanced life prediction analysis procedure, as applied to CA-101 (cast IN 792 + Hf), an alloy proposed for turbine disks in automotive gas turbine engines. The methodology was successful in predicting specimen life under thermal-mechanical cycling, to within a factor of + or - 2.

Considering Life Cycle during Design: A Longitudinal Study of Engineering Undergraduates. Research Brief

ERIC Educational Resources Information Center

Yasuhara, Ken; Morozov, Andrew; Kilgore, Deborah; Atman, Cynthia; Loucks-Jaret, Christine

2009-01-01

In this age of global warming and diminishing fossil fuel stores, society is becoming increasingly aware that seemingly small decisions can have surprisingly far-reaching implications on the environment and future generations. Accordingly, today's engineers must approach design problems with a holistic, broad view of the impacts,…

Nox Emission Reduction in Commercial Jets Through Water Injection

NASA Technical Reports Server (NTRS)

Balepin, Vladimir; Ossello, Chris; Snyder, Chris

2002-01-01

This paper discusses a method of the nitrogen oxides (NOx) emission reduction through the injection of water in commercial turbofan engines during the takeoff and climbout cycles. In addition to emission reduction, this method can significantly reduce turbine temperature during the most demanding operational modes (takeoff and climbout) and increase engine reliability and life.

Study on energy consumption evaluation of mountainous highway based on LCA

NASA Astrophysics Data System (ADS)

Fei, Lunlin; Zhang, Qi; Xie, Yongqing

2017-06-01

For the system to understand the road construction energy consumption process, this paper selects a typical mountainous highway in the south, using the theory and method of Life Cycle Assessment (LCA) to quantitatively study the energy consumption of the whole process of highway raw materials production, construction and operation. The results show that the energy consumption in the raw material production stage is the highest, followed by the highway operation and construction stage. The energy consumption per unit of tunnel engineering, bridge engineering, roadbed engineering and pavement engineering in the construction phase are 2279.00 tce, 1718.07 tce, 542.19 tce and 34.02 tce, and in operational phase, 85.44% of electricity consumption comes from tunnel ventilation and lighting. Therefore, in the bridge and tunnel construction process, we should promote energy-saving innovation of the construction technology and mechanical equipment, and further strengthen the research and development of tunnel ventilation, lighting energy-saving equipment and intelligent control technology, which will help significantly reduce the energy consumption and greenhouse gas emissions of the life cycle of highway.

General aviation internal-combustion engine research programs at NASA-Lewis Research Center

NASA Technical Reports Server (NTRS)

Willis, E. A.

1978-01-01

An update is presented of non-turbine general aviation engine programs. The program encompasses conventional, lightweight diesel and rotary engines. It's three major thrusts are: (1) reduced SFC's; (2) improved fuels tolerance; and (3) reduced emissions. Current and planned future programs in such areas as lean operation, improved fuel management, advanced cooling techniques and advanced engine concepts, are described. These are expected to lay the technology base, by the mid to latter 1980's, for engines whose life cycle fuel costs are 30 to 50% lower than today's conventional engines.

Analysis of the Seismic Performance of Isolated Buildings according to Life-Cycle Cost

PubMed Central

Dang, Yu; Han, Jian-ping; Li, Yong-tao

2015-01-01

This paper proposes an indicator of seismic performance based on life-cycle cost of a building. It is expressed as a ratio of lifetime damage loss to life-cycle cost and determines the seismic performance of isolated buildings. Major factors are considered, including uncertainty in hazard demand and structural capacity, initial costs, and expected loss during earthquakes. Thus, a high indicator value indicates poor building seismic performance. Moreover, random vibration analysis is conducted to measure structural reliability and evaluate the expected loss and life-cycle cost of isolated buildings. The expected loss of an actual, seven-story isolated hospital building is only 37% of that of a fixed-base building. Furthermore, the indicator of the structural seismic performance of the isolated building is much lower in value than that of the structural seismic performance of the fixed-base building. Therefore, isolated buildings are safer and less risky than fixed-base buildings. The indicator based on life-cycle cost assists owners and engineers in making investment decisions in consideration of structural design, construction, and expected loss. It also helps optimize the balance between building reliability and building investment. PMID:25653677

Analysis of the seismic performance of isolated buildings according to life-cycle cost.

PubMed

Dang, Yu; Han, Jian-Ping; Li, Yong-Tao

2015-01-01

This paper proposes an indicator of seismic performance based on life-cycle cost of a building. It is expressed as a ratio of lifetime damage loss to life-cycle cost and determines the seismic performance of isolated buildings. Major factors are considered, including uncertainty in hazard demand and structural capacity, initial costs, and expected loss during earthquakes. Thus, a high indicator value indicates poor building seismic performance. Moreover, random vibration analysis is conducted to measure structural reliability and evaluate the expected loss and life-cycle cost of isolated buildings. The expected loss of an actual, seven-story isolated hospital building is only 37% of that of a fixed-base building. Furthermore, the indicator of the structural seismic performance of the isolated building is much lower in value than that of the structural seismic performance of the fixed-base building. Therefore, isolated buildings are safer and less risky than fixed-base buildings. The indicator based on life-cycle cost assists owners and engineers in making investment decisions in consideration of structural design, construction, and expected loss. It also helps optimize the balance between building reliability and building investment.

Hybrid life-cycle assessment of natural gas based fuel chains for transportation.

PubMed

Strømman, Anders Hammer; Solli, Christian; Hertwich, Edgar G

2006-04-15

This research compares the use of natural gas, methanol, and hydrogen as transportation fuels. These three fuel chains start with the extraction and processing of natural gas in the Norwegian North Sea and end with final use in Central Europe. The end use is passenger transportation with a sub-compact car that has an internal combustion engine for the natural gas case and a fuel cell for the methanol and hydrogen cases. The life cycle assessment is performed by combining a process based life-cycle inventory with economic input-output data. The analysis shows that the potential climate impacts are lowest for the hydrogen fuel scenario with CO2 deposition. The hydrogen fuel chain scenario has no significant environmental disadvantage compared to the other fuel chains. Detailed analysis shows that the construction of the car contributes significantly to most impact categories. Finally, it is shown how the application of a hybrid inventory model ensures a more complete inventory description compared to standard process-based life-cycle assessment. This is particularly significant for car construction which would have been significantly underestimated in this study using standard process life-cycle assessment alone.

Presentation on systems cluster research

NASA Technical Reports Server (NTRS)

Morgenthaler, George W.

1989-01-01

This viewgraph presentation presents an overview of systems cluster research performed by the Center for Space Construction. The goals of the research are to develop concepts, insights, and models for space construction and to develop systems engineering/analysis curricula for training future aerospace engineers. The following topics are covered: CSC systems analysis/systems engineering (SIMCON) model, CSC systems cluster schedule, system life-cycle, model optimization techniques, publications, cooperative efforts, and sponsored research.

Implementing Effective Mission Systems Engineering Practices During Early Project Formulation Phases

NASA Technical Reports Server (NTRS)

Moton, Tryshanda

2016-01-01

Developing and implementing a plan for a NASA space mission can be a complicated process. The needs, goals, and objectives of any proposed mission or technology must be assessed early in the Project Life Cycle. The key to successful development of a space mission or flight project is the inclusion of systems engineering in early project formulation, namely during Pre-phase A, Phase A, and Phase B of the NASA Project Life Cycle. When a space mission or new technology is in pre-development, or "pre-Formulation", feasibility must be determined based on cost, schedule, and risk. Inclusion of system engineering during project formulation is key because in addition to assessing feasibility, design concepts are developed and alternatives to design concepts are evaluated. Lack of systems engineering involvement early in the project formulation can result in increased risks later in the implementation and operations phases of the project. One proven method for effective systems engineering practice during the pre-Formulation Phase is the use of a mission conceptual design or technology development laboratory, such as the Mission Design Lab (MDL) at NASA's Goddard Space Flight Center (GSFC). This paper will review the engineering process practiced routinely in the MDL for successful mission or project development during the pre-Formulation Phase.

Early Engagement of Safety and Mission Assurance Expertise Using Systems Engineering Tools: A Risk-Based Approach to Early Identification of Safety and Assurance Requirements

NASA Technical Reports Server (NTRS)

Darpel, Scott; Beckman, Sean

2016-01-01

Decades of systems engineering practice have demonstrated that the earlier the identification of requirements occurs, the lower the chance that costly redesigns will needed later in the project life cycle. A better understanding of all requirements can also improve the likelihood of a design's success. Significant effort has been put into developing tools and practices that facilitate requirements determination, including those that are part of the model-based systems engineering (MBSE) paradigm. These efforts have yielded improvements in requirements definition, but have thus far focused on a design's performance needs. The identification of safety & mission assurance (S&MA) related requirements, in comparison, can occur after preliminary designs are already established, yielding forced redesigns. Engaging S&MA expertise at an earlier stage, facilitated by the use of MBSE tools, and focused on actual project risk, can yield the same type of design life cycle improvements that have been realized in technical and performance requirements.

An IMS Station life cycle from a sustainment point of view

NASA Astrophysics Data System (ADS)

Brely, Natalie; Gautier, Jean-Pierre; Foster, Daniel

2014-05-01

The International Monitoring System (IMS) is to consist of 321 monitoring facilities, composed of four different technologies with a variety of designs and equipment types, deployed in a range of environments around the globe. The International Monitoring System is conceived to operate in perpetuity through maintenance, replacement and recapitalization of IMS facilities' infrastructure and equipment when the end of service life is reached [CTBT/PTS/INF.1163]. Life Cycle techniques and modellization are being used by the PTS to plan and forecast life cycle sustainment requirements of IMS facilities. Through historical data analysis, Engineering inputs and Feedback from experienced Station Operators, the PTS currently works towards increasing the level of confidence on these forecasts and sustainment requirements planning. Continued validation, feedback and improvement of source data from scientific community and experienced users is sought and essential in order to ensure limited effect on data availability and optimal costs (human and financial).

The application of probabilistic design theory to high temperature low cycle fatigue

NASA Technical Reports Server (NTRS)

Wirsching, P. H.

1981-01-01

Metal fatigue under stress and thermal cycling is a principal mode of failure in gas turbine engine hot section components such as turbine blades and disks and combustor liners. Designing for fatigue is subject to considerable uncertainty, e.g., scatter in cycles to failure, available fatigue test data and operating environment data, uncertainties in the models used to predict stresses, etc. Methods of analyzing fatigue test data for probabilistic design purposes are summarized. The general strain life as well as homo- and hetero-scedastic models are considered. Modern probabilistic design theory is reviewed and examples are presented which illustrate application to reliability analysis of gas turbine engine components.

Review of the Fuel Saving, Life Cycle GHG Emission, and Ownership Cost Impacts of Lightweighting Vehicles with Different Powertrains.

PubMed

Luk, Jason M; Kim, Hyung Chul; De Kleine, Robert; Wallington, Timothy J; MacLean, Heather L

2017-08-01

The literature analyzing the fuel saving, life cycle greenhouse gas (GHG) emission, and ownership cost impacts of lightweighting vehicles with different powertrains is reviewed. Vehicles with lower powertrain efficiencies have higher fuel consumption. Thus, fuel savings from lightweighting internal combustion engine vehicles can be higher than those of hybrid electric and battery electric vehicles. However, the impact of fuel savings on life cycle costs and GHG emissions depends on fuel prices, fuel carbon intensities and fuel storage requirements. Battery electric vehicle fuel savings enable reduction of battery size without sacrificing driving range. This reduces the battery production cost and mass, the latter results in further fuel savings. The carbon intensity of electricity varies widely and is a major source of uncertainty when evaluating the benefits of fuel savings. Hybrid electric vehicles use gasoline more efficiently than internal combustion engine vehicles and do not require large plug-in batteries. Therefore, the benefits of lightweighting depend on the vehicle powertrain. We discuss the value proposition of the use of lightweight materials and alternative powertrains. Future assessments of the benefits of vehicle lightweighting should capture the unique characteristics of emerging vehicle powertrains.

Software engineering and simulation

NASA Technical Reports Server (NTRS)

Zhang, Shou X.; Schroer, Bernard J.; Messimer, Sherri L.; Tseng, Fan T.

1990-01-01

This paper summarizes the development of several automatic programming systems for discrete event simulation. Emphasis is given on the model development, or problem definition, and the model writing phases of the modeling life cycle.

Outbrief - Long Life Rocket Engine Panel

NASA Technical Reports Server (NTRS)

Quinn, Jason Eugene

2004-01-01

This white paper is an overview of the JANNAF Long Life Rocket Engine (LLRE) Panel results from the last several years of activity. The LLRE Panel has met over the last several years in order to develop an approach for the development of long life rocket engines. Membership for this panel was drawn from a diverse set of the groups currently working on rocket engines (Le. government labs, both large and small companies and university members). The LLRE Panel was formed in order to determine the best way to enable the design of rocket engine systems that have life capability greater than 500 cycles while meeting or exceeding current performance levels (Specific Impulse and Thrust/Weight) with a 1/1,OOO,OOO likelihood of vehicle loss due to rocket system failure. After several meetings and much independent work the panel reached a consensus opinion that the primary issues preventing LLRE are a lack of: physics based life prediction, combined loads prediction, understanding of material microphysics, cost effective system level testing. and the inclusion of fabrication process effects into physics based models. With the expected level of funding devoted to LLRE development, the panel recommended that fundamental research efforts focused on these five areas be emphasized.

Plug cluster module demonstration

NASA Technical Reports Server (NTRS)

Rousar, D. C.

1978-01-01

The low pressure, film cooled rocket engine design concept developed during two previous ALRC programs was re-evaluated for application as a module for a plug cluster engine capable of performing space shuttle OTV missions. The nominal engine mixture ratio was 5.5 and the engine life requirements were 1200 thermal cycles and 10 hours total operating life. The program consisted of pretest analysis; engine tests, performed using residual components; and posttest analysis. The pretest analysis indicated that operation of the operation of the film cooled engine at O/F = 5.5 was feasible. During the engine tests, steady state wall temperature and performance measurement were obtained over a range of film cooling flow rates, and the durability of the engine was demonstrated by firing the test engine 1220 times at a nominal performance ranging from 430 - 432 seconds. The performance of the test engine was limited by film coolant sleeve damage which had occurred during previous testing. The post-test analyses indicated that the nominal performance level can be increased to 436 seconds.

Hydrogen Internal Combustion Engine (ICE) Vehicles and Fueling Infrastructure : Alternative Fuels & Life-Cycle Engineering Program : November 29, 2006 to November 28, 2011

DOT National Transportation Integrated Search

2011-12-20

Wind turbines located on sites known as wind farms have become popular in the United States and elsewhere because they may be able to reduce, if not replace, the use of fossil fuels for energy production. The development of wind farms has been partic...

Design Knowledge Management System (DKMS) Beta Test Report

DTIC Science & Technology

1992-11-01

design process. These problems, which include knowledge representation, constraint propagation, model design, and information integration, are...effective delivery of life-cycle engineering knowledge assistance and information to the design/engineering activities. It does not matter whether these...platfomi. 4. Reuse - existing data, information , and knowledge can be reused. 5. Remote Execution -- automatically handles remote execution without

The US Army Corps of Engineers Roadmap for Life-Cycle Building Information Modeling (BIM)

DTIC Science & Technology

2012-11-01

Building Information Modeling ( BIM ) En gi ne er R es ea rc h an...Abstract Building Information Modeling ( BIM ) technology has rapidly gained ac- ceptance throughout the planning, architecture, engineering...the Industry Foundation Class (IFC) definitions to create vendor-neutral data exchanges for use in BIM software tools. Building Information Modeling

High-Cycle Fatigue Resistance of Si-Mo Ductile Cast Iron as Affected by Temperature and Strain Rate

NASA Astrophysics Data System (ADS)

Matteis, Paolo; Scavino, Giorgio; Castello, Alessandro; Firrao, Donato

2015-09-01

Silicon-molybdenum ductile cast irons are used to fabricate exhaust manifolds of internal combustion engines of large series cars, where the maximum pointwise temperature at full engine load may be higher than 973 K (700 °C). In this application, high-temperature oxidation and thermo-mechanical fatigue (the latter being caused by the engine start and stop and by the variation of its power output) have been the subject of several studies and are well known, whereas little attention has been devoted to the high-cycle fatigue, arising from the engine vibration. Therefore, the mechanical behavior of Si-Mo cast iron is studied here by means of stress-life fatigue tests up to 10 million cycles, at temperatures gradually increasing up to 973 K (700 °C). The mechanical characterization is completed by tensile and compressive tests and ensuing fractographic examinations; the mechanical test results are correlated with the cast iron microstructure and heat treatment.

Experimental and analytical study of ceramic-coated turbine-tip shroud seals for small turbine engines

NASA Technical Reports Server (NTRS)

Biesiadny, T. J.; Mcdonald, G. E.; Hendricks, R. C.; Little, J. K.; Robinson, R. A.; Klann, G. A.; Lassow, E. S.

1985-01-01

The results of an experimental and analytical evaluation of ceramic turbine tip shrouds within a small turbine engine operating environment are presented. The ceramic shrouds were subjected to 1001 cycles between idle and high power and steady-state conditions for a total of 57.8 engine hr. Posttest engine inspection revealed mud-flat surface cracking, which was attributed to microcracking under tension with crack penetration to the ceramic and bond coat interface. Sections and micrographs tend to corroborate the thesis. The engine test data provided input to a thermomechanical analysis to predict temperature and stress profiles throughout the ceramic gas-path seal. The analysis predicts cyclic thermal stresses large enough to cause the seal to fail. These stresses are, however, mitigated by inelastic behavior of the shroud materials and by the microfracturing that tensile stresses produce. Microfracturing enhances shroud longevity during early life but provides the failure mechanism during life but provides the failure mechanism during extended life when coupled with the time dependent inelastic materials effects.

Contingency power concepts for helicopter turboshaft engine

NASA Technical Reports Server (NTRS)

Hirschkron, R.; Davis, R. H.; Goldstein, D. N.; Haynes, J. F.; Gauntner, J. W.

1984-01-01

Twin helicopter engines are often sized by power requirement of safe mission completion after the failure of one of the two engines. This study was undertaken for NASA Lewis by General Electric Co. to evaluate the merits of special design features to provide a 2-1/2 minute Contingency Power rating, permitting an engine size reduction. The merits of water injection, cooling flow modulation, throttle push and an auxiliary power plant were evaluated using military life cycle cost (LCC) and commercial helicopter direct operating cost (DOC) merit factors in a rubber engine/rubber aircraft scenario.

Emergence of life from multicomponent mixtures of chemicals: the case for experiments with cycling physicochemical gradients.

PubMed

Spitzer, Jan

2013-04-01

The emergence of life from planetary multicomponent mixtures of chemicals is arguably the most complicated and least understood natural phenomenon. The fact that living cells are non-equilibrium systems suggests that life can emerge only from non-equilibrium chemical systems. From an astrobiological standpoint, non-equilibrium chemical systems arise naturally when solar irradiation strikes rotating surfaces of habitable planets: the resulting cycling physicochemical gradients persistently drive planetary chemistries toward "embryonic" living systems and an eventual emergence of life. To better understand the factors that lead to the emergence of life, I argue for cycling non-equilibrium experiments with multicomponent chemical systems designed to represent the evolving chemistry of Hadean Earth ("prebiotic soups"). Specifically, I suggest experimentation with chemical engineering simulators of Hadean Earth to observe and analyze (i) the appearances and phase separations of surface active and polymeric materials as precursors of the first "cell envelopes" (membranes) and (ii) the accumulations, commingling, and co-reactivity of chemicals from atmospheric, oceanic, and terrestrial locations.

Turbine blade tip durability analysis

NASA Technical Reports Server (NTRS)

Mcknight, R. L.; Laflen, J. H.; Spamer, G. T.

1981-01-01

An air-cooled turbine blade from an aircraft gas turbine engine chosen for its history of cracking was subjected to advanced analytical and life-prediction techniques. The utility of advanced structural analysis techniques and advanced life-prediction techniques in the life assessment of hot section components are verified. Three dimensional heat transfer and stress analyses were applied to the turbine blade mission cycle and the results were input into advanced life-prediction theories. Shortcut analytical techniques were developed. The proposed life-prediction theories are evaluated.

Creep fatigue life prediction for engine hot section materials (ISOTROPIC)

NASA Technical Reports Server (NTRS)

Nelson, R. S.; Schoendorf, J. F.; Lin, L. S.

1986-01-01

The specific activities summarized include: verification experiments (base program); thermomechanical cycling model; multiaxial stress state model; cumulative loading model; screening of potential environmental and protective coating models; and environmental attack model.

Wiseman in Node 2

NASA Image and Video Library

2014-06-17

ISS040-E-012306 (16 June 2014) --- NASA astronaut Reid Wiseman, Expedition 40 flight engineer, conducts an Extravehicular Mobility Unit (EMU) long life battery (LLB) auto-cycle initiate in the Harmony node of the International Space Station.

Buffer thermal energy storage for a solar thermal powered 1-MW sub e electrical plant

NASA Astrophysics Data System (ADS)

Polzien, R. E.

The application of a latent heat thermal energy buffer storage (TEBS) subsystem to the small community solar thermal power experiment (SCSE) is discussed. The SCSE is a 1-MW sub e solar thermal electric plant consisting of multiple paraboloidal concentrators with an organic Rankine cycle power conversion unit mounted at the focus of each concentrator. Objective of the TEBS is to minimize plant shutdowns during intermittent cloud coverage thereby improving life expectancy of major subsystems. An SCSE plant performance model is used with time varying insolation to show that 70 to 80 percent of the potential engine shutdowns may be averted with the TEBS system. Parametric variation of engine life dependency on start/stop cycles shows the potential for a 4 percent reduction in levelized bus bar energy cost using TEBS.

Engineering sustainable development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prendergast, J.

1993-10-01

This article discusses sustainable development, a policy which attempts to balance environmental preservation and economic growth, and promises a way to provide a decent life for Earth's human inhabitants without destroying the global ecosystem. Sustainable development is an effort to use technology to help clean up the mess it helped make, and engineers will be central players in its success or failure. Key aspects include more efficient energy use through conservation measures and switching to renewable sources, waste minimization, much greater recycling and reuse of materials, more comprehensive economic/environmental assessments employing life-cycle analyses, and better management of resources.

Elevated temperature biaxial fatigue

NASA Technical Reports Server (NTRS)

Jordan, E. H.

1983-01-01

Biaxial fatigue is often encountered in the complex thermo-mechanical loadings present in gas turbine engines. Engine strain histories can involve non-constant temperature, mean stress, creep, environmental effects, both isotropic and anisotropic materials and non-proportional loading. Life prediction for the general case involving all the above factors is not a practicable research project. The current research program is limited to isothermal fatigue at room temperature and 1200 F of Hastalloy-X for both proportional and non-proportional loading. An improved method for predicting the fatigue life and deformation response under biaxial cycle loading is sought.

Research on Building Education & Workforce Capacity in Systems Engineering

DTIC Science & Technology

2011-10-31

product or prototype that addresses a real DoD need. Implemented as pilot courses in eight civilian and six military universities affiliated with...Engineering 1 1.1 Computer Engineering 1 1.1 Operations Research 1 1.1 Product Architecture 1 1.1 Total 93 100.0 Table 7: Breakdown of Student... product specifications, inattention to budget limits and safety issues, inattention to product life cycle, poor implementation of risk management plans

Life Cycle Assessment of landfill biogas management: sensitivity to diffuse and combustion air emissions.

PubMed

Beylot, Antoine; Villeneuve, Jacques; Bellenfant, Gaël

2013-02-01

GOAL AND SCOPE: The life cycle inventory of landfill emissions is a key point in Life Cycle Assessment (LCA) of waste management options and is highly subject to discussion. Result sensitivity to data inventory is accounted for through the implementation of scenarios that help examine how waste landfilling should be modeled in LCA. Four landfill biogas management options are environmentally evaluated in a Life Cycle Assessment perspective: (1) no biogas management (open dump), conventional landfill with (2) flaring, (3) combined heat and power (CHP) production in an internal combustion engine and (4) biogas upgrading for use as a fuel in buses. Average, maximum and minimum literature values are considered both for combustion emission factors in flares and engines and for trace pollutant concentrations in biogas. Biogas upgrading for use as a fuel in buses appears as the most relevant option with respect to most non-toxic impact categories and ecotoxicity, when considering average values for trace gas concentrations and combustion emission factors. Biogas combustion in an engine for CHP production shows the best performances in terms of climate change, but generates significantly higher photochemical oxidant formation and marine eutrophication impact potentials than flaring or biogas upgrading for use as a fuel in buses. However the calculated environmental impact potentials of landfill biogas management options depend largely on the trace gas concentrations implemented in the model. The use of average or extreme values reported in the literature significantly modifies the impact potential of a given scenario (up to two orders of magnitude for open dumps with respect to human toxicity). This should be taken into account when comparing landfilling with other waste management options. Also, the actual performances of a landfill top cover (in terms of oxidation rates) and combustion technology (in terms of emission factors) appear as key parameters affecting the ranking of biogas management options. Copyright © 2012 Elsevier Ltd. All rights reserved.

Vehicle's lightweight design vs. electrification from life cycle assessment perspective

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayyas, Ahmad; Omar, Mohammed; Hayajneh, Mohammed

Lightwiegh materials and vehicles' electrification are among the most viable and economic solutions to improve fuel ecocnmoy of vehicles and reduce environmental impacts in the operational phase of typical vehicle's life cycle span. This study aims to shed more light on the combined effect of lightweighing and electrification by assessing different lightweight designs and electric powetrians from the environmental perspective using a life cycle analysis coupled with an emphasis on energy expenditures and carbon dioxide emissions. This article discusses the life cycle assessment for several advanced powertrains namely; plug-in hybrid electric vehicles (PHEV), battery electric vehicles (BEV) and hybrid electricmore » vehicles (HEV) relative to the conventional gasoline operated internal combustion engine based power train vehicles. The main focus will be on the energy greenhouse gas emissions (GHG) in the material extraction and resources phase, manufacturing phase and use phase (operation and maintenance). While most of the current studies focus on the use phase that does not reflect the correct environmental impacts associated with advanced powertrains, thus the presented text applies a holistic LCA approach that covers pre-manufacturing, manufacturing, operational and end-of-life phases, plus another indirect phase to account for fuel extraction, refining and transportation to the end-users or customers. Based on the LCA emissions results, one may infer that environmental policies that reduce emissions rates from the electricity sector can mitigate this effect without completely eliminating it. Interestingly, the analysis show that lightweight vehicles with internal combustion engines have less impacts on the environment as a direct result of upstream emissions associated with electricity generation in United States. This scenario can differ in other countries with higher renewable and sustainable energy generated electric powers.« less

Vehicle's lightweight design vs. electrification from life cycle assessment perspective

DOE PAGES

Mayyas, Ahmad; Omar, Mohammed; Hayajneh, Mohammed; ...

2017-08-17

Lightwiegh materials and vehicles' electrification are among the most viable and economic solutions to improve fuel ecocnmoy of vehicles and reduce environmental impacts in the operational phase of typical vehicle's life cycle span. This study aims to shed more light on the combined effect of lightweighing and electrification by assessing different lightweight designs and electric powetrians from the environmental perspective using a life cycle analysis coupled with an emphasis on energy expenditures and carbon dioxide emissions. This article discusses the life cycle assessment for several advanced powertrains namely; plug-in hybrid electric vehicles (PHEV), battery electric vehicles (BEV) and hybrid electricmore » vehicles (HEV) relative to the conventional gasoline operated internal combustion engine based power train vehicles. The main focus will be on the energy greenhouse gas emissions (GHG) in the material extraction and resources phase, manufacturing phase and use phase (operation and maintenance). While most of the current studies focus on the use phase that does not reflect the correct environmental impacts associated with advanced powertrains, thus the presented text applies a holistic LCA approach that covers pre-manufacturing, manufacturing, operational and end-of-life phases, plus another indirect phase to account for fuel extraction, refining and transportation to the end-users or customers. Based on the LCA emissions results, one may infer that environmental policies that reduce emissions rates from the electricity sector can mitigate this effect without completely eliminating it. Interestingly, the analysis show that lightweight vehicles with internal combustion engines have less impacts on the environment as a direct result of upstream emissions associated with electricity generation in United States. This scenario can differ in other countries with higher renewable and sustainable energy generated electric powers.« less

Cooled variable nozzle radial turbine for rotor craft applications

NASA Technical Reports Server (NTRS)

Rogo, C.

1981-01-01

An advanced, small 2.27 kb/sec (5 lbs/sec), high temperature, variable area radial turbine was studied for a rotor craft application. Variable capacity cycles including single-shaft and free-turbine engine configurations were analyzed to define an optimum engine design configuration. Parametric optimizations were made on cooled and uncooled rotor configurations. A detailed structural and heat transfer analysis was conducted to provide a 4000-hour life HP turbine with material properties of the 1988 time frame. A pivoted vane and a moveable sidewall geometry were analyzed. Cooling and variable geometry penalties were included in the cycle analysis. A variable geometry free-turbine engine configuration with a design 1477K (2200 F) inlet temperature and a compressor pressure ratio of 16:1 was selected. An uncooled HP radial turbine rotor with a moveable sidewall nozzle showed the highest performance potential for a time weighted duty cycle.

Propulsion system mathematical model for a lift/cruise fan V/STOL aircraft

NASA Technical Reports Server (NTRS)

Cole, G. L.; Sellers, J. F.; Tinling, B. E.

1980-01-01

A propulsion system mathematical model is documented that allows calculation of internal engine parameters during transient operation. A non-realtime digital computer simulation of the model is presented. It is used to investigate thrust response and modulation requirements as well as the impact of duty cycle on engine life and design criteria. Comparison of simulation results with steady-state cycle deck calculations showed good agreement. The model was developed for a specific 3-fan subsonic V/STOL aircraft application, but it can be adapted for use with any similar lift/cruise V/STOL configuration.

Comparative durability of timber bridges in the USA

Treesearch

James P. Wacker; Brian K. Brashaw

2017-01-01

As engineers begin to utilize life-cycle-cost design approaches for timber bridges, there is a necessity for more reliable data about their durability and expected service life. This paper summarizes a comprehensive effort to assess the current condition of more than one hundred timber highway bridge superstructures throughout the United States. This national study was...

An improved turbine disk design to increase reliability of aircraft jet engines

NASA Technical Reports Server (NTRS)

Barack, W. N.; Domas, P. A.

1976-01-01

An analytical study was performed on a novel disk design to replace the existing high-pressure turbine, stage 1 disk on the CF6-50 turbofan engine. Preliminary studies were conducted on seven candidate disk design concepts. An integral multidisk design with bore entry of the turbine blade cooling air was selected as the improved disk design. This disk has the unique feature of being redundant such that if one portion of the disk would fail, the remaining portion would prevent the release of large disk fragments from the turbine system. Low cycle fatigue lives, initial defect propagation lives, burst speed, and the kinetic energies of probable disk fragment configurations were calculated, and comparisons were made with the existing disk, both in its current material, IN 718, and with the substitution of an advanced alloy, Rene 95. The design for redundancy approach which necessitated the addition of approximately 44.5 kg (98 lb) to the design disk substantially improved the life of the disk. The life to crack initiation was increased from 30,000 cycles to more than 100,000 cycles. The cycles to failure from initial defect propagation were increased from 380 cycles to 1564 cycles. Burst speed was increased from 126 percent overspeed to 149 percent overspeed. Additionally, the maximum fragment energies associated with a failure were decreased by an order of magnitude.

Energy and emissions saving potential of additive manufacturing: the case of lightweight aircraft components

DOE PAGES

Huang, Runze; Riddle, Matthew; Graziano, Diane; ...

2015-05-08

Additive manufacturing (AM) holds great potential for improving materials efficiency, reducing life-cycle impacts, and enabling greater engineering functionality compared to conventional manufacturing (CM) processes. For these reasons, AM has been adopted by a growing number of aircraft component manufacturers to achieve more lightweight, cost-effective designs. This study estimates the net changes in life-cycle primary energy and greenhouse gas emissions associated with AM technologies for lightweight metallic aircraft components through the year 2050, to shed light on the environmental benefits of a shift from CM to AM processes in the U.S. aircraft industry. A systems modeling framework is presented, with integratesmore » engineering criteria, life-cycle environmental data, and aircraft fleet stock and fuel use models under different AM adoption scenarios. Estimated fleetwide life-cycle primary energy savings in a rapid adoption scenario reach 70-174 million GJ/year in 2050, with cumulative savings of 1.2-2.8 billion GJ. Associated cumulative emission reduction potentials of CO2e were estimated at 92.8-217.4 million metric tons. About 95% of the savings is attributed to airplane fuel consumption reductions due to lightweighting. In addition, about 4050 tons aluminum, 7600 tons titanium and 8100 tons of nickel alloys could be saved per year in 2050. The results indicate a significant role of AM technologies in helping society meet its long-term energy use and GHG emissions reduction goals, and highlight barriers and opportunities for AM adoption for the aircraft industry.« less

Energy and emissions saving potential of additive manufacturing: the case of lightweight aircraft components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Runze; Riddle, Matthew; Graziano, Diane

Additive manufacturing (AM) holds great potential for improving materials efficiency, reducing life-cycle impacts, and enabling greater engineering functionality compared to conventional manufacturing (CM) processes. For these reasons, AM has been adopted by a growing number of aircraft component manufacturers to achieve more lightweight, cost-effective designs. This study estimates the net changes in life-cycle primary energy and greenhouse gas emissions associated with AM technologies for lightweight metallic aircraft components through the year 2050, to shed light on the environmental benefits of a shift from CM to AM processes in the U.S. aircraft industry. A systems modeling framework is presented, with integratesmore » engineering criteria, life-cycle environmental data, and aircraft fleet stock and fuel use models under different AM adoption scenarios. Estimated fleetwide life-cycle primary energy savings in a rapid adoption scenario reach 70-174 million GJ/year in 2050, with cumulative savings of 1.2-2.8 billion GJ. Associated cumulative emission reduction potentials of CO2e were estimated at 92.8-217.4 million metric tons. About 95% of the savings is attributed to airplane fuel consumption reductions due to lightweighting. In addition, about 4050 tons aluminum, 7600 tons titanium and 8100 tons of nickel alloys could be saved per year in 2050. The results indicate a significant role of AM technologies in helping society meet its long-term energy use and GHG emissions reduction goals, and highlight barriers and opportunities for AM adoption for the aircraft industry.« less

Pavement management segment consolidation

DOT National Transportation Integrated Search

1998-01-01

Dividing roads into "homogeneous" segments has been a major problem for all areas of highway engineering. SDDOT uses Deighton Associates Limited software, dTIMS, to analyze life-cycle costs for various rehabilitation strategies on each segment of roa...

Systematic Curriculum Integration of Sustainable Development Using Life Cycle Approaches: The Case of the Civil Engineering Department at the Université de Sherbrooke

ERIC Educational Resources Information Center

Roure, Bastien; Anand, Chirjiv; Bisaillon, Véronique; Amor, Ben

2018-01-01

Purpose: The purpose of this paper is to provide a consistent and systematic integration framework of sustainable development (SD) in a civil engineering (CE) curriculum, given the connection between the two. Curriculum integration is a challenging project and requires the development of certain protocols to ensure success.…

Value Engineering. "A Working Tool for Cost Control in the Design of Educational Facilities."

ERIC Educational Resources Information Center

Lawrence, Jerry

Value Engineering (VE) is a cost optimizing technique used to analyze design quality and cost-effectiveness. The application of VE procedures to the design and construction of school facilities has been adopted by the state of Washington. By using VE, the optimum value for every life cycle dollar spent on a facility is obtained by identifying not…

Transition in Gas Turbine Engine Control System Architecture: Modular, Distributed, Embedded

DTIC Science & Technology

2009-08-01

Design + Development + Certification + Procurement + Life Cycle Cost = Net Savings for our Customers Approved for Public Release 16 Economic ...Supporting Small Quantity Electronics Need Broadly Applicable High Temperature Electronics Supply Base Approved for Public Release 17 Economic ...rc ec ures Approved for Public Release 18 Economic Drivers for New FADEC Designs FADEC Implementation Time Pacing Engine Development Issues • FADEC

Development of high-rise buildings: digitalization of life cycle management

NASA Astrophysics Data System (ADS)

Gusakova, Elena

2018-03-01

The analysis of the accumulated long-term experience in the construction and operation of high-rise buildings reveals not only the engineering specificity of such projects, but also systemic problems in the field of project management. Most of the project decisions are made by the developer and the investor in the early stages of the life cycle - from the acquisition of the site to the start of operation, so most of the participants in the construction and operation of the high-rise building are far from the strategic life-cycle management of the project. The solution of these tasks due to the informatization of management has largely exhausted its efficiency resource. This is due to the fact that the applied IT-systems automated traditional "inherited" processes and management structures, and, in addition, they were focused on informatization of the activities of the construction company, rather than the construction project. Therefore, in the development of high-rise buildings, the tasks of researching approaches and methods for managing the full life cycle of projects that will improve their competitiveness become topical. For this purpose, the article substantiates the most promising approaches and methods of informational modeling of high-rise construction as a basis for managing the full life cycle of this project. Reengineering of information interaction schemes for project participants is considered; formation of a unified digital environment for the life cycle of the project; the development of systems for integrating data management and project management.

V&V Plan for FPGA-based ESF-CCS Using System Engineering Approach.

NASA Astrophysics Data System (ADS)

Maerani, Restu; Mayaka, Joyce; El Akrat, Mohamed; Cheon, Jung Jae

2018-02-01

Instrumentation and Control (I&C) systems play an important role in maintaining the safety of Nuclear Power Plant (NPP) operation. However, most current I&C safety systems are based on Programmable Logic Controller (PLC) hardware, which is difficult to verify and validate, and is susceptible to software common cause failure. Therefore, a plan for the replacement of the PLC-based safety systems, such as the Engineered Safety Feature - Component Control System (ESF-CCS), with Field Programmable Gate Arrays (FPGA) is needed. By using a systems engineering approach, which ensures traceability in every phase of the life cycle, from system requirements, design implementation to verification and validation, the system development is guaranteed to be in line with the regulatory requirements. The Verification process will ensure that the customer and stakeholder’s needs are satisfied in a high quality, trustworthy, cost efficient and schedule compliant manner throughout a system’s entire life cycle. The benefit of the V&V plan is to ensure that the FPGA based ESF-CCS is correctly built, and to ensure that the measurement of performance indicators has positive feedback that “do we do the right thing” during the re-engineering process of the FPGA based ESF-CCS.

Fatigue Crack Growth Behavior Evaluation of Grainex Mar-M 247 for NASA's High Temperature, High Speed Turbine Seal Test Rig

NASA Technical Reports Server (NTRS)

Delgado, Irebert R.; Steinetz, Bruce M.; Rimnac, Clare M.; Lewandowski, John J.

2008-01-01

The fatigue crack growth behavior of Grainex Mar-M 247 is evaluated for NASA s Turbine Seal Test Facility. The facility is used to test air-to-air seals primarily for use in advanced jet engine applications. Because of extreme seal test conditions of temperature, pressure, and surface speeds, surface cracks may develop over time in the disk bolt holes. An inspection interval is developed to preclude catastrophic disk failure by using experimental fatigue crack growth data. By combining current fatigue crack growth results with previous fatigue strain-life experimental work, an inspection interval is determined for the test disk. The fatigue crack growth life of the NASA disk bolt holes is found to be 367 cycles at a crack depth of 0.501 mm using a factor of 2 on life at maximum operating conditions. Combining this result with previous fatigue strain-life experimental work gives a total fatigue life of 1032 cycles at a crack depth of 0.501 mm. Eddy-current inspections are suggested starting at 665 cycles since eddy current detection thresholds are currently at 0.381 mm. Inspection intervals are recommended every 50 cycles when operated at maximum operating conditions.

Digital electronic engine control history

NASA Technical Reports Server (NTRS)

Putnam, T. W.

1984-01-01

Full authority digital electronic engine controls (DEECs) were studied, developed, and ground tested because of projected benefits in operability, improved performance, reduced maintenance, improved reliability, and lower life cycle costs. The issues of operability and improved performance, however, are assessed in a flight test program. The DEEC on a F100 engine in an F-15 aircraft was demonstrated and evaluated. The events leading to the flight test program are chronicled and important management and technical results are identified.

Plastics disassembly versus bulk recycling: engineering design for end-of-life electronics resource recovery.

PubMed

Rios, Pedro; Stuart, Julie Ann; Grant, Ed

2003-12-01

Annual plastic flows through the business and consumer electronics manufacturing supply chain include nearly 3 billion lb of high-value engineering plastics derived from petroleum. The recovery of resource value from this stream presents critical challenges in areas of materials identification and recycling process design that demand new green engineering technologies applied together with life cycle assessment and ecological supply chain analysis to create viable plastics-to-plastics supply cycles. The sustainable recovery of potentially high-value engineering plastics streams requires that recyclers either avoid mixing plastic parts or purify later by separating smaller plastic pieces created in volume reduction (shredding) steps. Identification and separation constitute significant barriers in the plastics-to-plastics recycling value proposition. In the present work, we develop a model that accepts randomly arriving electronic products to study scenarios by which a recycler might identify and separate high-value engineering plastics as well as metals. Using discrete eventsimulation,we compare current mixed plastics recovery with spectrochemical plastic resin identification and subsequent sorting. Our results show that limited disassembly with whole-part identification can produce substantial yields in separated streams of recovered engineering thermoplastics. We find that disassembly with identification does not constitute a bottleneck, but rather, with relatively few workers, can be configured to pull the process and thus decrease maximum staging space requirements.

CF6 jet engine performance improvement: High pressure turbine roundness

NASA Technical Reports Server (NTRS)

Howard, W. D.; Fasching, W. A.

1982-01-01

An improved high pressure turbine stator reducing fuel consumption in current CF6-50 turbofan engines was developed. The feasibility of the roundness and clearance response improvements was demonstrated. Application of these improvements will result in a cruise SFC reduction of 0.22 percent for new engines. For high time engines, the improved roundness and response characteristics results in an 0.5 percent reduction in cruise SFC. A basic life capability of the improved HP turbine stator in over 800 simulated flight cycles without any sign of significant distress is shown.

Computer tools for systems engineering at LaRC

NASA Technical Reports Server (NTRS)

Walters, J. Milam

1994-01-01

The Systems Engineering Office (SEO) has been established to provide life cycle systems engineering support to Langley research Center projects. over the last two years, the computing market has been reviewed for tools which could enhance the effectiveness and efficiency of activities directed towards this mission. A group of interrelated applications have been procured, or are under development including a requirements management tool, a system design and simulation tool, and project and engineering data base. This paper will review the current configuration of these tools and provide information on future milestones and directions.

NCCLCS: LIFE CYCLE OF NANOMATERIALS (LCNANO)

EPA Science Inventory

Because engineered nanomaterials (NMs) have transformative benefits to individuals and society, they are being incorporated into many products. However, tremendous uncertainty presently exists in our ability to predict or manage risks from nano-enabled products across their...

Rapid Energy Modeling Workflow Demonstration Project

DTIC Science & Technology

2014-01-01

Conditioning Engineers BIM Building Information Model BLCC building life cycle costs BPA Building Performance Analysis CAD computer assisted...invited to enroll in the Autodesk Building Performance Analysis ( BPA ) Certificate Program under a group 30 specifically for DoD installation

Economic impacts of electric vehicle adoption.

DOT National Transportation Integrated Search

2017-02-01

The objective of the Economic Impacts of Electric Vehicle Adoption research project was to : examine the predicted levels of electric vehicle (EV) adoption, to analyze the life cycle costs of : EVs compared to internal combustion engine vehicles and ...

Means of storage and automated monitoring of versions of text technical documentation

NASA Astrophysics Data System (ADS)

Leonovets, S. A.; Shukalov, A. V.; Zharinov, I. O.

2018-03-01

The paper presents automation of the process of preparation, storage and monitoring of version control of a text designer, and program documentation by means of the specialized software is considered. Automation of preparation of documentation is based on processing of the engineering data which are contained in the specifications and technical documentation or in the specification. Data handling assumes existence of strictly structured electronic documents prepared in widespread formats according to templates on the basis of industry standards and generation by an automated method of the program or designer text document. Further life cycle of the document and engineering data entering it are controlled. At each stage of life cycle, archive data storage is carried out. Studies of high-speed performance of use of different widespread document formats in case of automated monitoring and storage are given. The new developed software and the work benches available to the developer of the instrumental equipment are described.

Kerosene-base fuels in small gasoline engines. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Failla, C.C.; Pouring, A.A.

1991-01-01

This document presents the results of an engineering study to demonstrate the technology for converting small gasoline spark-ignited engines, to burn kerosene type fuels to power small generators (0.5 to 3.0 kw). Commercially available (plus those in the developmental stage), reciprocating, two-stroke, four stroke and rotary engines were evaluated for their conversion potential. Unique combustion systems were identified and trade-off studies conducted on engine type, combustion systems, and modification required to burn kerosene type fuels, with special emphasis given to minimizing life cycle cost. Recommendations for the most feasible system are given.

Space shuttle main engine definition (phase B). Volume 2: Avionics. [for space shuttle

NASA Technical Reports Server (NTRS)

1971-01-01

The advent of the space shuttle engine with its requirements for high specific impulse, long life, and low cost have dictated a combustion cycle and a closed loop control system to allow the engine components to run close to operating limits. These performance requirements, combined with the necessity for low operational costs, have placed new demands on rocket engine control, system checkout, and diagnosis technology. Based on considerations of precision environment, and compatibility with vehicle interface commands, an electronic control, makes available many functions that logically provide the information required for engine system checkout and diagnosis.

The cell cycle.

PubMed

Singh, N; Lim, R B; Sawyer, M A

2000-07-01

The cell cycle and the cell cycle control system are the engines that drive life. They allow for the processes of cell renewal and the growth of organisms, under controlled conditions. The control system is essential for the monitoring of normal cell growth and replication of genetic material and to ensure that normal, functional daughter cells are produced at completion of each cell cycle. Although certain clinical applications exist which take advantage of the events of the cell cycle, our understanding of its mechanisms and how to manipulate them is infantile. The next decades will continue to see the effort of many researchers focused upon unlocking the mysteries of the cell cycle and the cell cycle control system.

The Effect of Drive Signal Limiting on High Cycle Fatigue Life Analysis

NASA Technical Reports Server (NTRS)

Kihm, Frederic; Rizzi, Stephen A.

2014-01-01

It is common practice to assume a Gaussian distribution of both the input acceleration and the response when modeling random vibration tests. In the laboratory, however, shaker controllers often limit the drive signal to prevent high amplitude peaks. The high amplitudes may either be truncated at a given level (socalled brick wall limiting or abrupt clipping), or compressed (soft limiting), resulting in drive signals which are no longer Gaussian. The paper first introduces several methods for limiting a drive signal, including brick wall limiting and compression. The limited signal is then passed through a linear time-invariant system representing a device under test. High cycle fatigue life predictions are subsequently made using spectral fatigue and rainflow cycle counting schemes. The life predictions are compared with those obtained from unclipped input signals. Some guidelines are provided to help the test engineer decide how clipping should be applied under different test scenarios.

Life Cycle Assessment of Connected and Automated Vehicles: Sensing and Computing Subsystem and Vehicle Level Effects.

PubMed

Gawron, James H; Keoleian, Gregory A; De Kleine, Robert D; Wallington, Timothy J; Kim, Hyung Chul

2018-03-06

Although recent studies of connected and automated vehicles (CAVs) have begun to explore the potential energy and greenhouse gas (GHG) emission impacts from an operational perspective, little is known about how the full life cycle of the vehicle will be impacted. We report the results of a life cycle assessment (LCA) of Level 4 CAV sensing and computing subsystems integrated into internal combustion engine vehicle (ICEV) and battery electric vehicle (BEV) platforms. The results indicate that CAV subsystems could increase vehicle primary energy use and GHG emissions by 3-20% due to increases in power consumption, weight, drag, and data transmission. However, when potential operational effects of CAVs are included (e.g., eco-driving, platooning, and intersection connectivity), the net result is up to a 9% reduction in energy and GHG emissions in the base case. Overall, this study highlights opportunities where CAVs can improve net energy and environmental performance.

General aviation internal combustion engine research programs at NASA-Lewis Research Center

NASA Technical Reports Server (NTRS)

Willis, E. A.

1978-01-01

An update is presented of non-turbine general aviation engine programs underway at the NASA-Lewis Research Center in Cleveland, Ohio. The program encompasses conventional, lightweight diesel and rotary engines. Its three major thrusts are: (a) reduced SFC's; (b) improved fuels tolerance; and (c) reducing emissions. Current and planned future programs in such areas as lean operation, improved fuel management, advanced cooling techniques and advanced engine concepts, are described. These are expected to lay the technology base, by the mid to late 1980's, for engines whose life cycle fuel costs are 30 to 50% lower than today's conventional engines.

Life-Cycle Analysis of Aircraft Turbine Engines

DTIC Science & Technology

1977-11-01

actual experience. Mixed but promisng results were obtained in modeling ownership costs for military engines. Depot maintenance costs were more...Acquisition Experience, The Rand Corporation, RM-6072-PR, November 1969. System Acquisition Stategies , The Rand Corporation, R-733-PR/ARPA, June 1971. 98...Paris, 1971I. Phillips. Almarin, Technology and Market Structure, IA•xington Books, D.C. Heath and Company, Lexington, Mass.. 1971. A Position Paper on

Silicon Wafer Advanced Packaging (SWAP). Multichip Module (MCM) Foundry Study. Version 2

DTIC Science & Technology

1991-04-08

Next Layer Dielectric Spacing - Additional Metal Thickness Impact on Dielectric Uniformity/Adhiesion. The first step in .!Ie EPerimental design would be... design CAM - computer aided manufacturing CAE - computer aided engineering CALCE - computer aided life cycle engineering center CARMA - computer aided...expansion 5 j- CVD - chemical vapor deposition J . ..- j DA - design automation J , DEC - Digital Equipment Corporation --- DFT - design for testability

Using Maxwell's Demon to Tame the "Devil in the Details" that are Encountered During System Development

NASA Technical Reports Server (NTRS)

Richardson, David

2018-01-01

Model-Based Systems Engineering (MBSE) is the formalized application of modeling to support system requirements, design, analysis, verification and validation activities beginning in the conceptual design phase and continuing throughout development and later life cycle phases . This presentation will discuss the value proposition that MBSE has for Systems Engineering, and the associated culture change needed to adopt it.

Risk Informed Design as Part of the Systems Engineering Process

NASA Technical Reports Server (NTRS)

Deckert, George

2010-01-01

This slide presentation reviews the importance of Risk Informed Design (RID) as an important feature of the systems engineering process. RID is based on the principle that risk is a design commodity such as mass, volume, cost or power. It also reviews Probabilistic Risk Assessment (PRA) as it is used in the product life cycle in the development of NASA's Constellation Program.

Acquiring Technical Data With Renewable Real Options

DTIC Science & Technology

2016-04-30

Development, and Engineering Center, 2009). Faced with diminishing sources for M2 .50 caliber machine gun parts , an Army engineering center entered the...data needed for life cycle sustainment functions such as maintenance or competitive spare parts procurement, but this expectation is more complicated...than it seems (DoD, 2015). The needs and timing for competitive spare parts procurement are uncertain, and changes in system configuration or

USA Science and Engineering Festival

NASA Image and Video Library

2010-10-23

Young visitors to the inaugural USA Science and Engineering Festival at the National Mall in Washington, D.C., learn about the life cycle of a star at an exhibit sponsored by the John C. Stennis Space Center Education Office. Stennis personnel participated in the final weekend of the Oct. 10-24 festival with education activities and to present information on its new Spaced Out Sports Design Challenge.

Software Engineering Education Directory

DTIC Science & Technology

1988-01-01

Dana Hausman and Suzanne Woolf were crucial to the successful completion of this edition of the directory. Their teamwork, energy, and dedication...for this directory began in the summer of 1986 with a questionnaire mailed to schools selected from Peterson’s Graduate Programs in Engineering and...Christoper, and Siegel, Stan Software Cost Estimation and Life-Cycle Control by Putnam, Lawrence H. Software Quality Assurance: A Practical Approach by

Life-cycle assessment of engineered nanomaterials: a literature review of assessment status

NASA Astrophysics Data System (ADS)

Miseljic, Mirko; Olsen, Stig I.

2014-06-01

The potential environmental impacts of engineered nanomaterials (ENMs), and their engineered nanoparticles (ENPs), have, in recent years, been a cause of concern. Life-cycle assessment (LCA) is a highly qualified tool to assess products and systems and has an increasing extent been applied to ENMs. However, still only 29 case studies on LCA of ENMs have been published in journals and this article investigates these studies. Generally, data on production of ENMs as well as the coverage of the life cycle are limited. In particular, within use and disposal stages data are scarce due to many unknowns regarding the potential release and fate of ENMs/ENPs to and in the environment. This study investigates the sensitivity of case studies with respect to ecotoxicity impacts through a quantification of the potential ecotoxicity impacts to algae, daphnia and fish as a result of direct release of Ag and TiO2 ENPs (mainly <200 nm in nominal diameter size) from various ENM products to the freshwater compartment. It was found that Ag and TiO2 release, from 1 g Ag or TiO2 ENM product, poses up to ca. 3.5 orders of magnitude higher ecotoxicity impact than the production of 1 g polymer (PP, PE and PET average) or 1 Wh of grid mix electricity from Scandinavia. ENMs from Ag had higher ecotoxic impact than those from TiO2 and there was a linear regression between Ag ENM content in the considered products and the potential ecotoxicity impacts to the freshwater species, according to release of total Ag during use (mainly washing).

Specialty Engineering Supplement to IEEE-15288.1

DTIC Science & Technology

2015-05-15

receiver required to work in a dense EMI environment. (15) Any RF receiver with a burnout level of less than 30 dBm (1 mW). b. A summary of all...Context 2.1 ISO-IEC-IEEE-15288: 2015, Systems and Software Engineering — System life cycle processes ISO-IEC-IEEE 15288 is the DOD-adopted standard for...to ISO-15288 for application of systems engineering on defense programs that was developed by a joint services working group under the auspices of the

Operability engineering in the Deep Space Network

NASA Technical Reports Server (NTRS)

Wilkinson, Belinda

1993-01-01

Many operability problems exist at the three Deep Space Communications Complexes (DSCC's) of the Deep Space Network (DSN). Four years ago, the position of DSN Operability Engineer was created to provide the opportunity for someone to take a system-level approach to solving these problems. Since that time, a process has been developed for personnel and development engineers and for enforcing user interface standards in software designed for the DSCC's. Plans are for the participation of operations personnel in the product life-cycle to expand in the future.

The Application of Design to Cost and Life Cycle to Aircraft Engines.

DTIC Science & Technology

1980-05-01

appearing in both columns include AGE (common and peculiar), transportation, management, and training. These cost elements are not usually large in...Proc. of install engine X CIP x Spare engine X Spare parts (base/depot) X Depot labor X Base labor X ECPs-mod/retro X X AGE (peculiar/common) X X...introduits de maniere aleatoire dans le cadre j’hypotheses. En outre les moteurs ou les sous-ensembles, compte tenu du suivi de leur age et de leur

Common Analysis Tool Being Developed for Aeropropulsion: The National Cycle Program Within the Numerical Propulsion System Simulation Environment

NASA Technical Reports Server (NTRS)

Follen, Gregory J.; Naiman, Cynthia G.

1999-01-01

The NASA Lewis Research Center is developing an environment for analyzing and designing aircraft engines-the Numerical Propulsion System Simulation (NPSS). NPSS will integrate multiple disciplines, such as aerodynamics, structure, and heat transfer, and will make use of numerical "zooming" on component codes. Zooming is the coupling of analyses at various levels of detail. NPSS uses the latest computing and communication technologies to capture complex physical processes in a timely, cost-effective manner. The vision of NPSS is to create a "numerical test cell" enabling full engine simulations overnight on cost-effective computing platforms. Through the NASA/Industry Cooperative Effort agreement, NASA Lewis and industry partners are developing a new engine simulation called the National Cycle Program (NCP). NCP, which is the first step toward NPSS and is its initial framework, supports the aerothermodynamic system simulation process for the full life cycle of an engine. U.S. aircraft and airframe companies recognize NCP as the future industry standard common analysis tool for aeropropulsion system modeling. The estimated potential payoff for NCP is a $50 million/yr savings to industry through improved engineering productivity.

National Cycle Program (NCP) Common Analysis Tool for Aeropropulsion

NASA Technical Reports Server (NTRS)

Follen, G.; Naiman, C.; Evans, A.

1999-01-01

Through the NASA/Industry Cooperative Effort (NICE) agreement, NASA Lewis and industry partners are developing a new engine simulation, called the National Cycle Program (NCP), which is the initial framework of NPSS. NCP is the first phase toward achieving the goal of NPSS. This new software supports the aerothermodynamic system simulation process for the full life cycle of an engine. The National Cycle Program (NCP) was written following the Object Oriented Paradigm (C++, CORBA). The software development process used was also based on the Object Oriented paradigm. Software reviews, configuration management, test plans, requirements, design were all apart of the process used in developing NCP. Due to the many contributors to NCP, the stated software process was mandatory for building a common tool intended for use by so many organizations. The U.S. aircraft and airframe companies recognize NCP as the future industry standard for propulsion system modeling.

Small Engine Component Technology (SECT) study

NASA Technical Reports Server (NTRS)

Singh, B.

1986-01-01

Small advanced (450 to 850 pounds thrust, 2002 to 3781 N) gas turbine engines were studied for a subsonic strategic cruise missile application, using projected year 2000 technology. An aircraft, mission characteristics, and baseline (state-of-the-art) engine were defined to evaluate technology benefits. Engine performance and configuration analyses were performed for two and three spool turbofan and propfan engine concepts. Mission and Life Cycle Cost (LCC) analyses were performed in which the candidate engines were compared to the baseline engines over a prescribed mission. The advanced technology engines reduced system LCC up to 41 percent relative to the baseline engine. Critical aerodynamic, materials, and mechanical systems turbine engine technologies were identified and program plans were defined for each identified critical technology.

AN ADVANCED SYSTEM FOR POLLUTION PREVENTION IN CHEMICAL COMPLEXES

EPA Science Inventory

One important accomplishment is that the system will give process engineers interactively and simultaneously use of programs for total cost analysis, life cycle assessment and sustainability metrics to provide direction for the optimal chemical complex analysis pro...

Effect of environment on low-cycle fatigue of a nickel-titanium instrument.

PubMed

Cheung, Gary S P; Shen, Ya; Darvell, Brian W

2007-12-01

This study examined the low-cycle fatigue (LCF) behavior of a nickel-titanium (NiTi) engine-file under various environmental conditions. One brand of NiTi instrument was subjected to rotational-bending fatigue in air, deionized water, sodium hypochlorite, or silicone oil. The curvature of each instrument, diameter of the fracture cross-section, and the number of rotations to failure were determined. The strain-life relationship in the LCF region was examined by using one-way analysis of variance, and the number of crack origins with chi2, for differences between groups. The results showed a linear relationship, on logarithmic scales, between the LCF life and the surface strain amplitude; regression line slopes were significantly different between noncorrosive (air, silicone oil) and corrosive (water, hypochlorite) environments (P < .05), as well as number of crack origins (P < .05). Hypochlorite was more detrimental to fatigue life than water. In conclusion, environmental conditions significantly affect the LCF behavior of NiTi rotary instruments. Fatigue testing of NiTi engine-files should be in a service-like environment.

Erosion Coatings Developed to Increase the Life and Durability of Composites

NASA Technical Reports Server (NTRS)

Sutter, James K.; Naik, Subhash K.; Bowman, Cheryl L.; Siefker, Robert; Miyoshi, Kazuhisa; Perusek, Gail P.

2004-01-01

Both the NASA Glenn Research Center and the Allison Advanced Development Company (AADC) have worked to develop and demonstrate erosion-resistant coatings that would increase the life and durability of composite materials used in commercial aircraft engines. These composite materials reduce component weight by 20 to 30 percent and result in less fuel burn and emissions and more fuel savings. Previously, however, their use was limited because of poor erosion resistance, which causes concerns about safety and leads to high maintenance costs. The coatings were tested by the University of Cincinnati, and the composites were manufactured by Texas Composites and coated by Engelhard and NASA Glenn. Rolls-Royce Corporation uses composite materials, which are stronger and less dense than steel or titanium, to make bypass vanes for their AE3007 engines. These engines are widely used in regional jet aircraft (Embraer) and unmanned air vehicles such as the Northrop Grumman Global Hawk. Coatings developed by NASA/Rolls-Royce can reduce erosion from abrasive materials and from impurities in the air that pass over these vanes, allowing Rolls-Royce to take advantage of the benefits of composite materials over titanium without the added costs of increased maintenance and/or engine failure. The Higher Operating Temperature Propulsion Components (HOTPC) Project developed cost-effective, durable coatings as part of NASA's goal to increase aviation system capacity growth. These erosion coatings will reduce the number of special inspections or instances of discontinued service due to erosion, allowing aircraft capacity to be maintained without inconveniencing the traveling public. A specific example of extending component life showed that these coatings increased the life of graphite fiber and polymer composite bypass vanes up to 8 times over that of the uncoated vanes. This increased durability allows components to operate to full design life without the fear of wear or failure. Recently, Rolls-Royce completed over 2000 hr of engine testing with the coated fan exit bypass vanes. There was no loss of coating after nearly 5000 typical engine cycles. Midway through the engine tests, the coated vanes were removed from the engine during a scheduled maintenance and inspection period. The vanes were shipped back to Glenn, where they underwent further stress testing in the Structural Dynamics Lab, mimicking more extreme conditions than those typical of the AE3007 engine cycle. These vanes were then replaced in the AE3007 and subjected to another 1000 hr of engine tests. Once again, there was no loss of coating and only a minimal appearance of cracking.

Achieving Closure for Bioregenerative Life Support Systems: Engineering and Ecological Challenges, Research Opportunities

NASA Astrophysics Data System (ADS)

Dempster, William; Allen, John P.

Closed systems are desirable for a number of purposes: space life support systems where precious life-supporting resources need to be kept inside; biospheric systems; where global ecological pro-cesses can be studied in great detail and testbeds where research topics requiring isolation from the outside (e.g. genetically modified organisms; radioisotopes) can be studied in isolation from the outside environment and where their ecological interactions and fluxes can be studied. But to achieve and maintain closure raises both engineering and ecological challenges. Engineering challenges include methods of achieving closure for structures of different materials, and devel-oping methods of allowing energy (for heating and cooling) and information transfer through the materially closed structure. Methods of calculating degree of closure include measuring degradation rates of inert trace gases introduced into the system. An allied problem is devel-oping means of locating where leaks are located so that they may be repaired and degree of closure maintained. Once closure is achieved, methods of dealing with the pressure differen-tials between inside and outside are needed: from inflatable structures which might adjust to the pressure difference to variable volume chambers attached to the life systems component. These issues are illustrated through the engineering employed at Biosphere 2, the Biosphere 2 Test Module and the Laboratory Biosphere and a discussion of methods used by other closed ecological system facility engineers. Ecological challenges include being able to handle faster cycling rates and accentuated daily and seasonal fluxes of critical life elements such as carbon dioxide, oxygen, water, macro-and mico-nutrients. The problems of achieving sustainability in closed systems for life support include how to handle atmospheric dynamics including trace gases, producing a complete human diet and recycling nutrients and maintaining soil fertility, healthy air and water and preventing the loss of crucial elements from active circulation. In biospheric facilities the challenge is also to produce analogue to natural biomes and ecosys-tems, studying processes of self-organization and adaptation in systems that allow specification or determination of state variables and cycles which may be followed through all interactions from atmosphere to soils.

Enriching step-based product information models to support product life-cycle activities

NASA Astrophysics Data System (ADS)

Sarigecili, Mehmet Ilteris

The representation and management of product information in its life-cycle requires standardized data exchange protocols. Standard for Exchange of Product Model Data (STEP) is such a standard that has been used widely by the industries. Even though STEP-based product models are well defined and syntactically correct, populating product data according to these models is not easy because they are too big and disorganized. Data exchange specifications (DEXs) and templates provide re-organized information models required in data exchange of specific activities for various businesses. DEXs show us it would be possible to organize STEP-based product models in order to support different engineering activities at various stages of product life-cycle. In this study, STEP-based models are enriched and organized to support two engineering activities: materials information declaration and tolerance analysis. Due to new environmental regulations, the substance and materials information in products have to be screened closely by manufacturing industries. This requires a fast, unambiguous and complete product information exchange between the members of a supply chain. Tolerance analysis activity, on the other hand, is used to verify the functional requirements of an assembly considering the worst case (i.e., maximum and minimum) conditions for the part/assembly dimensions. Another issue with STEP-based product models is that the semantics of product data are represented implicitly. Hence, it is difficult to interpret the semantics of data for different product life-cycle phases for various application domains. OntoSTEP, developed at NIST, provides semantically enriched product models in OWL. In this thesis, we would like to present how to interpret the GD & T specifications in STEP for tolerance analysis by utilizing OntoSTEP.

Evaluation Of Model Based Systems Engineering Processes For Integration Into Rapid Acquisition Programs

DTIC Science & Technology

2016-09-01

Failure MTBCF Mean Time Between Critical Failure MIRV Multiple Independently-targetable Reentry Vehicle MK6LE MK6 Guidance System Life Extension...programs were the MK54 Lightweight Torpedo program, a Raytheon Radar program, and the Life Extension of the MK6 Guidance System (MK6LE) of the...activities throughout the later life -cycle phases. MBSE allowed the programs to manage the evolution of simulation capabilities, as well as to assess the

Science and Technology in Development Environments - Industry and Department of Defense Case Studies

DTIC Science & Technology

2003-11-01

an acronym for Product and Cycle Time Excellence, is designed to manage product development , business development , and business alliance processes...experiments. 3. Test Practicality—Pilot development with limited production. 4. Prove Profitability—Pilot production. 5. Manage Life Cycle —Manufacturing and...compressor, particularly in a turbofan configuration, was developed primarily under a CIP for these two engines. The TF30 and F100 experiences provide

Conceptual design study of an improved gas turbine powertrain

NASA Technical Reports Server (NTRS)

Chapman, W. I.

1980-01-01

The conceptual design for an improved gas turbine (IGT) powertrain and vehicle was investigated. Cycle parameters, rotor systems, and component technology were reviewed and a dual rotor gas turbine concept was selected and optimized for best vehicle fuel economy. The engine had a two stage centrifugal compressor with a design pressure ratio of 5.28, two axial turbine stages with advanced high temperature alloy integral wheels, variable power turbine nozzle for turbine temperature and output torque control, catalytic combustor, and annular ceramic recuperator. The engine was rated at 54.81 kW, using water injection on hot days to maintain vehicle acceleration. The estimated vehicle fuel economy was 11.9 km/l in the combined driving cycle, 43 percent over the 1976 compact automobile. The estimated IGT production vehicle selling price was 10 percent over the comparable piston engine vehicle, but the improved fuel economy and reduced maintenance and repair resulted in a 9 percent reduction in life cycle cost.

Biodiesel Research : Alternative Fuels & Life-Cycle Engineering Program : November 29, 2006 to November 28, 2011

DOT National Transportation Integrated Search

2011-12-20

The primary objective of this project is to develop multiple simulation Testbeds/transportation models to evaluate the impacts of DMA connected vehicle applications and the active and dynamic transportation management (ATDM) strategies. The outputs (...

23 CFR 661.21 - When is a bridge eligible for rehabilitation?

Code of Federal Regulations, 2014 CFR

2014-04-01

... Section 661.21 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND... eligible for rehabilitation may be replaced if the life cycle cost analysis is conducted which shows the cost for bridge rehabilitation exceeds the replacement cost. ...

23 CFR 661.21 - When is a bridge eligible for rehabilitation?

Code of Federal Regulations, 2013 CFR

2013-04-01

... Section 661.21 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND... eligible for rehabilitation may be replaced if the life cycle cost analysis is conducted which shows the cost for bridge rehabilitation exceeds the replacement cost. ...

23 CFR 661.21 - When is a bridge eligible for rehabilitation?

Code of Federal Regulations, 2012 CFR

2012-04-01

... Section 661.21 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND... eligible for rehabilitation may be replaced if the life cycle cost analysis is conducted which shows the cost for bridge rehabilitation exceeds the replacement cost. ...

Project Management of Army Aircraft Survivability Equipment

DTIC Science & Technology

1976-11-01

develop- ment trade-offs; and request for proposal (RFP) reviews involving advanced development (AD), engineering development (ED), and pro- ducibility...Safety: Ensur~e that adequate consideration is given safetyf throughout the life cycle of aviation surviva- bility equipment. -13. Project Manager Training...rate management effort to assure an orderly progression through its life cyIcle. Many of the items carry an urgent priority for worldwide applicatic

Gasoline-powered serial hybrid cars cause lower life cycle carbon emissions than battery cars

NASA Astrophysics Data System (ADS)

Meinrenken, Christoph J.; Lackner, Klaus S.

2011-04-01

Battery cars powered by grid electricity promise reduced life cycle green house gas (GHG) emissions from the automotive sector. Such scenarios usually point to the much higher emissions from conventional, internal combustion engine cars. However, today's commercially available serial hybrid technology achieves the well known efficiency gains from regenerative breaking, lack of gearbox, and light weighting - even if the electricity is generated onboard, from conventional fuels. Here, we analyze emissions for commercially available, state-of the-art battery cars (e.g. Nissan Leaf) and those of commercially available serial hybrid cars (e.g., GM Volt, at same size and performance). Crucially, we find that serial hybrid cars driven on (fossil) gasoline cause fewer life cycle GHG emissions (126g CO2e per km) than battery cars driven on current US grid electricity (142g CO2e per km). We attribute this novel finding to the significant incremental life cycle emissions from battery cars from losses during grid transmission, battery dis-/charging, and larger batteries. We discuss crucial implications for strategic policy decisions towards a low carbon automotive sector as well as relative land intensity when powering cars by biofuel vs. bioelectricity.

Creep fatigue life prediction for engine hot section materials (isotropic)

NASA Technical Reports Server (NTRS)

Moreno, Vito; Nissley, David; Lin, Li-Sen Jim

1985-01-01

The first two years of a two-phase program aimed at improving the high temperature crack initiation life prediction technology for gas turbine hot section components are discussed. In Phase 1 (baseline) effort, low cycle fatigue (LCF) models, using a data base generated for a cast nickel base gas turbine hot section alloy (B1900+Hf), were evaluated for their ability to predict the crack initiation life for relevant creep-fatigue loading conditions and to define data required for determination of model constants. The variables included strain range and rate, mean strain, strain hold times and temperature. None of the models predicted all of the life trends within reasonable data requirements. A Cycle Damage Accumulation (CDA) was therefore developed which follows an exhaustion of material ductility approach. Material ductility is estimated based on observed similarities of deformation structure between fatigue, tensile and creep tests. The cycle damage function is based on total strain range, maximum stress and stress amplitude and includes both time independent and time dependent components. The CDA model accurately predicts all of the trends in creep-fatigue life with loading conditions. In addition, all of the CDA model constants are determinable from rapid cycle, fully reversed fatigue tests and monotonic tensile and/or creep data.

Durability testing of the AJ10-221 490 N high performance (321 sec Isp) engine

NASA Technical Reports Server (NTRS)

Jassowski, D. M.; Rosenberg, S. D.; Schoenman, L.

1993-01-01

The durability of the 490 N AJ10-221 engine is characterized on the basis of data from 93 tests and a total firing life of 6.3 hr. For the three Ir/Re chambers tested, no limiting conditions were encountered in the 43,379 sec and 229 test thermal cycles. A wide range of off nominal operating conditions was successfully demonstrated.

Rotorcraft contingency power study

NASA Technical Reports Server (NTRS)

Hirschkron, R.; Haynes, J. F.; Goldstein, D. N.; Davis, R. H.

1984-01-01

Twin helicopter engines are often sized by the power requirement of a safe mission completion after the failure of one of the two engines. This study was undertaken for NASA Lewis by General Electric Co. to evaluate the merits of special design features to provide a 2-1/2 Contingency Power rating, permitting an engine size reduction. The merits of water injection, turbine cooling airflow modulation, throttle push, and a propellant auxiliary power plant were evaluated using military Life Cycle Cost (LCC) and commercial helicopter Direct Operating Cost (DOC) merit factors in a rubber engine and a rubber aircraft scenario.

Advanced propulsion system concept for hybrid vehicles

NASA Technical Reports Server (NTRS)

Bhate, S.; Chen, H.; Dochat, G.

1980-01-01

A series hybrid system, utilizing a free piston Stirling engine with a linear alternator, and a parallel hybrid system, incorporating a kinematic Stirling engine, are analyzed for various specified reference missions/vehicles ranging from a small two passenger commuter vehicle to a van. Parametric studies for each configuration, detail tradeoff studies to determine engine, battery and system definition, short term energy storage evaluation, and detail life cycle cost studies were performed. Results indicate that the selection of a parallel Stirling engine/electric, hybrid propulsion system can significantly reduce petroleum consumption by 70 percent over present conventional vehicles.

Analysis of methods for determining high cycle fatigue strength of a material with investigation of titanium-aluminum-vanadium gigacycle fatigue behavior

NASA Astrophysics Data System (ADS)

Pollak, Randall D.

Today, aerospace engineers still grapple with the qualitative and quantitative understanding of fatigue behavior in the design and testing of turbine-driven jet engines. The Department of Defense has taken a very active role in addressing this problem with the formation of the National High Cycle Fatigue Science & Technology Program in 1994. The primary goal of this program is to further the understanding of high cycle fatigue (HCF) behavior and develop methods in order to mitigate the negative impact of HCF on aerospace operations. This research supports this program by addressing the fatigue strength testing guidance currently provided by the DoD to engine manufacturers, with the primary goal to investigate current methods and recommend a test strategy to characterize the fatigue strength of a material at a specified number of cycles, such as the 109 design goal specified by MIL-HDBK-1783B, or range of cycles. The research utilized the benefits of numerical simulation to initially investigate the staircase method for use in fatigue strength testing. The staircase method is a commonly used fatigue strength test, but its ability to characterize fatigue strength variability is extremely suspect. A modified staircase approach was developed and shown to significantly reduce bias and scatter in estimates for fatigue strength variance. Experimental validation of this proposed test strategy was accomplished using a dual-phase Ti-6Al-4V alloy. The HCF behavior of a second material with a very different microstructure (beta annealed Ti-6Al-4V) was also investigated. The random fatigue limit (RFL) model, a recently developed analysis tool, was investigated to characterize stress-life behavior but found to have difficulty representing fatigue life curves with sharp transitions. Two alternative models (bilinear and hyperbolic) were developed based on maximum likelihood methods to better characterize the Ti-6Al-4V fatigue life behavior. These models provided a good fit to the experimental data for the dual-phase Ti-6Al-4V and were applied to the beta annealed variant in order to estimate stress-life behavior using a small-sample approach. Based on this research, designers should be better able to make reliable estimates of fatigue strength parameters using small-sample testing.

Resource utilization during software development

NASA Technical Reports Server (NTRS)

Zelkowitz, Marvin V.

1988-01-01

This paper discusses resource utilization over the life cycle of software development and discusses the role that the current 'waterfall' model plays in the actual software life cycle. Software production in the NASA environment was analyzed to measure these differences. The data from 13 different projects were collected by the Software Engineering Laboratory at NASA Goddard Space Flight Center and analyzed for similarities and differences. The results indicate that the waterfall model is not very realistic in practice, and that as technology introduces further perturbations to this model with concepts like executable specifications, rapid prototyping, and wide-spectrum languages, we need to modify our model of this process.

Interior Fracture Mechanism Analysis and Fatigue Life Prediction of Surface-Hardened Gear Steel under Axial Loading.

PubMed

Li, Wei; Deng, Hailong; Liu, Pengfei

2016-10-18

The interior defect-induced fracture of surface-hardened metallic materials in the long life region has become a key issue on engineering design. In the present study, the axial loading test with fully reversed condition was performed to examine the fatigue property of a surface-carburized low alloy gear steel in the long life region. Results show that this steel represents the duplex S-N (stress-number of cycles) characteristics without conventional fatigue limit related to 10⁷ cycles. Fatigue cracks are all originated from the interior inclusions in the matrix region due to the inhabitation effect of carburized layer. The inclusion induced fracture with fisheye occurs in the short life region below 5 × 10⁵ cycles, whereas the inclusion induced fracture with fine granular area (FGA) and fisheye occurs in the long life region beyond 10⁶ cycles. The stress intensity factor range at the front of FGA can be regarded as the threshold value controlling stable growth of interior long crack. The evaluated maximum inclusion size in the effective damage volume of specimen is about 27.29 μm. Considering the size relationships between fisheye and FGA, and inclusion, the developed life prediction method involving crack growth can be acceptable on the basis of the good agreement between the predicted and experimental results.

10 CFR 436.101 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... (hardware). Jet fuel means fuels for use, generally in aircraft turbine engines. Life cycle cost means the... plant, or a field facility. Maintenance means activities undertaken to assure that equipment and energy... out the responsibilities assigned to it. Renewable energy sources means sunlight, wind, geothermal...

10 CFR 436.101 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... (hardware). Jet fuel means fuels for use, generally in aircraft turbine engines. Life cycle cost means the... plant, or a field facility. Maintenance means activities undertaken to assure that equipment and energy... out the responsibilities assigned to it. Renewable energy sources means sunlight, wind, geothermal...

10 CFR 436.101 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... (hardware). Jet fuel means fuels for use, generally in aircraft turbine engines. Life cycle cost means the... plant, or a field facility. Maintenance means activities undertaken to assure that equipment and energy... out the responsibilities assigned to it. Renewable energy sources means sunlight, wind, geothermal...

10 CFR 436.101 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... (hardware). Jet fuel means fuels for use, generally in aircraft turbine engines. Life cycle cost means the... plant, or a field facility. Maintenance means activities undertaken to assure that equipment and energy... out the responsibilities assigned to it. Renewable energy sources means sunlight, wind, geothermal...

10 CFR 436.101 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... (hardware). Jet fuel means fuels for use, generally in aircraft turbine engines. Life cycle cost means the... plant, or a field facility. Maintenance means activities undertaken to assure that equipment and energy... out the responsibilities assigned to it. Renewable energy sources means sunlight, wind, geothermal...

Integrated Modeling Environment

NASA Technical Reports Server (NTRS)

Mosier, Gary; Stone, Paul; Holtery, Christopher

2006-01-01

The Integrated Modeling Environment (IME) is a software system that establishes a centralized Web-based interface for integrating people (who may be geographically dispersed), processes, and data involved in a common engineering project. The IME includes software tools for life-cycle management, configuration management, visualization, and collaboration.

Updating the U.S. Life Cycle GHG Petroleum Baseline to 2014 with Projections to 2040 Using Open-Source Engineering-Based Models.

PubMed

Cooney, Gregory; Jamieson, Matthew; Marriott, Joe; Bergerson, Joule; Brandt, Adam; Skone, Timothy J

2017-01-17

The National Energy Technology Laboratory produced a well-to-wheels (WTW) life cycle greenhouse gas analysis of petroleum-based fuels consumed in the U.S. in 2005, known as the NETL 2005 Petroleum Baseline. This study uses a set of engineering-based, open-source models combined with publicly available data to calculate baseline results for 2014. An increase between the 2005 baseline and the 2014 results presented here (e.g., 92.4 vs 96.2 g CO 2 e/MJ gasoline, + 4.1%) are due to changes both in modeling platform and in the U.S. petroleum sector. An updated result for 2005 was calculated to minimize the effect of the change in modeling platform, and emissions for gasoline in 2014 were about 2% lower than in 2005 (98.1 vs 96.2 g CO 2 e/MJ gasoline). The same methods were utilized to forecast emissions from fuels out to 2040, indicating maximum changes from the 2014 gasoline result between +2.1% and -1.4%. The changing baseline values lead to potential compliance challenges with frameworks such as the Energy Independence and Security Act (EISA) Section 526, which states that Federal agencies should not purchase alternative fuels unless their life cycle GHG emissions are less than those of conventionally produced, petroleum-derived fuels.

Performance Evaluation and Modeling of Erosion Resistant Turbine Engine Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Miller, Robert A.; Zhu, Dongming; Kuczmarski, Maria

2008-01-01

The erosion resistant turbine thermal barrier coating system is critical to the rotorcraft engine performance and durability. The objective of this work was to determine erosion resistance of advanced thermal barrier coating systems under simulated engine erosion and thermal gradient environments, thus validating a new thermal barrier coating turbine blade technology for future rotorcraft applications. A high velocity burner rig based erosion test approach was established and a new series of rare earth oxide- and TiO2/Ta2O5- alloyed, ZrO2-based low conductivity thermal barrier coatings were designed and processed. The low conductivity thermal barrier coating systems demonstrated significant improvements in the erosion resistance. A comprehensive model based on accumulated strain damage low cycle fatigue is formulated for blade erosion life prediction. The work is currently aiming at the simulated engine erosion testing of advanced thermal barrier coated turbine blades to establish and validate the coating life prediction models.

Information Product Development: Data product life cycle links engineering, science, and applications

NASA Astrophysics Data System (ADS)

Stavros, E. N.; Owen, S. E.

2016-12-01

Information products are assimilated and used to: a) conduct scientific research and b) provide decision support for management and policy. For example, aboveground biomass (i.e. an information product) can be integrated into Earth system models to test hypotheses about the changing world, or used to inform decision-making with respect to natural resource management and policy. Production and dissemination of an information product is referred to as the data product life cycle, which includes: 1) identifying needed information from decision-makers and researchers, 2) engineering an instrument and collecting the raw physical measurements (e.g, number of photons returned), 3) the scientific algorithm(s) for processing the data into an observable (e.g., number of dying trees), and 4) the integration and utilization of that observables by researchers and decision-makers. In this talk, I will discuss the data product life cycle in detail and provide examples from the pre-Hyperspectral Infrared Imager (HyspIRI) airborne campaign and the upcoming NASA-ISRO Synthetic Aperture Radar (NISAR) mission. Examples will focus on information products related to terrestrial ecosystems and natural resource management and will demonstrate that the key to providing information products for advancing scientific understanding and informing decision-makers, is the interdisciplinary integration of science, engineering and applied science - noting that applied science defines the wider impact and adoption of scientific principles by a wider community. As pre-HyspIRI airborne data is for research and development and NISAR is not yet launched, examples will include current plans for developing exemplar data products (from pre-HyspIRI) and the mission Applications Plan (for NISAR). Copyright 2016 California Institute of Technology. All Rights Reserved. We acknowledge support of the US Government, NASA, the Earth Science Division and Terrestrial Ecology program.

Analysis of a diesel-electric hybrid urban bus system

NASA Astrophysics Data System (ADS)

Marr, W. W.; Sekar, R. R.; Ahlheim, M. C.

A hybrid bus powered by a diesel engine and a battery pack was analyzed over an idealized bus-driving cycle in Chicago. Three hybrid configurations, two parallel and one series, were evaluated. The results indicate that the fuel economy of a hybrid bus, taking into account the regenerative braking, is comparable with that of a conventional diesel bus. Life-cycle costs are slightly higher because of the added weight and cost of the battery.

Role of High-End Computing in Meeting NASA's Science and Engineering Challenges

NASA Technical Reports Server (NTRS)

Biswas, Rupak

2006-01-01

High-End Computing (HEC) has always played a major role in meeting the modeling and simulation needs of various NASA missions. With NASA's newest 62 teraflops Columbia supercomputer, HEC is having an even greater impact within the Agency and beyond. Significant cutting-edge science and engineering simulations in the areas of space exploration, Shuttle operations, Earth sciences, and aeronautics research, are already occurring on Columbia, demonstrating its ability to accelerate NASA s exploration vision. The talk will describe how the integrated supercomputing production environment is being used to reduce design cycle time, accelerate scientific discovery, conduct parametric analysis of multiple scenarios, and enhance safety during the life cycle of NASA missions.

Hydrogen-oxygen auxiliary propulsion for the space shuttle. Volume 1: High pressure thrusters

NASA Technical Reports Server (NTRS)

1973-01-01

Technology for long life, high performing, gaseous hydrogen-gaseous oxygen rocket engines suitable for auxiliary propulsion was provided by a combined analytical and experimental program. Propellant injectors, fast response valves, igniters, and regeneratively and film-cooled thrust chambers were tested over a wide range of operating conditions. Data generated include performance, combustion efficiency, thermal characteristics film cooling effectiveness, dynamic response in pulsing, and cycle life limitations.

Lean, Premixed-Prevaporized (LPP) combustor conceptual design study

NASA Technical Reports Server (NTRS)

Dickman, R. A.; Dodds, W. J.; Ekstedt, E. E.

1979-01-01

Four combustion systems were designed and sized for the energy efficient engine. A fifth combustor was designed for the cycle and envelope of the twin-spool, high bypass ratio, high pressure ratio turbofan engine. Emission levels, combustion performance, life, and reliability assessments were made for these five combustion systems. Results of these design studies indicate that cruise NOx emission can be reduced by the use of lean, premixed-prevaporaized combustion and airflow modulation.

Projected Commercial Maritime Activity in the Western Arctic

DTIC Science & Technology

1977-10-01

for Polar Icebreaking 1967. Coast GuarC, U.S., Office of Engineering, Life Cycle Costs of Diesel Electric Propulsion Plants for a 20,000 SHP Polar...Dynamics, Electric Boat Division, Program Plan for Arctic Offshore Drilling System. 1970. Geological Survey, U.S., Mineral and Water Resources of Alaska...Port and Ocean EngineerLng under Arctic Conditions, Vol. I, Trondheim, Norway: Terhnical Institute of ’Norway, Page 37 Weeks, W. F. and Frankenstein

Engineering Challenges for Closed Ecological System facilities

NASA Astrophysics Data System (ADS)

Dempster, William; Nelson, Mark; Allen, John P.

2012-07-01

Engineering challenges for closed ecological systems include methods of achieving closure for structures of different materials, and developing methods of allowing energy (for heating and cooling) and information transfer through the materially closed structure. Methods of calculating degree of closure include measuring degradation rates of inert trace gases introduced into the system. An allied problem is developing means of locating where leaks are located so that they may be repaired and degree of closure maintained. Once closure is achieved, methods of dealing with the pressure differentials between inside and outside are needed: from inflatable structures which might adjust to the pressure difference to variable volume chambers attached to the life systems component. These issues are illustrated through the engineering employed at Biosphere 2, the Biosphere 2 Test Module and the Laboratory Biosphere and a discussion of methods used by other closed ecological system facility engineers. Ecological challenges include being able to handle faster cycling rates and accentuated daily and seasonal fluxes of critical life elements such as carbon dioxide, oxygen, water, macro- and mico-nutrients. The problems of achieving sustainability in closed systems for life support include how to handle atmospheric dynamics including trace gases, producing a complete human diet and recycling nutrients and maintaining soil fertility, healthy air and water and preventing the loss of crucial elements from active circulation. In biospheric facilities the challenge is also to produce analogue to natural biomes and ecosystems, studying processes of self-organization and adaptation in systems that allow specification or determination of state variables and cycles which may be followed through all interactions from atmosphere to soils.

FME Senior Project Managers: A Juggling Act of Multiple Projects | Poster

Cancer.gov

By Peggy Pearl, Contributing Writer It was not until the 1950s that organizations in the United States began to apply project management tools and techniques to complex construction and engineering projects (http://en.m.wikipedia.org/wiki/Project_life_cycle).

Solar-energy conversion system provides electrical power and thermal control for life-support systems

NASA Technical Reports Server (NTRS)

Davis, B. K.

1974-01-01

System utilizes Freon cycle and includes boiler turbogenerator with heat exchanger, regenerator and thermal-control heat exchangers, low-pressure and boiler-feed pumps, and condenser. Exchanger may be of interest to engineers and scientists investigating new energy sources.

Assessing Environmental Impacts of Biofuels using Life-Cycle-Based Approaches

EPA Science Inventory

There is no simple answer to the question “are materials and products that are made from biofeedstocks environmentally sustainable?” However, thinking holistically allows decision-makers to view the potential ‘cradle-to-grave’ environmental impacts of the engineered systems that ...

Innovative Airbreathing Propulsion Concepts for Access to Space

NASA Technical Reports Server (NTRS)

Whitlow, Jr., Woodrow; Blech, Richard A.; Blankson, Isaiah M.

2001-01-01

This paper will present technologies and concepts for novel aeropropulsion systems. These technologies will enhance the safety of operations, reduce life cycle costs, and contribute to reduced costs of air travel and access to space. One of the goals of the NASA program is to reduce the carbon-dioxide emissions of aircraft engines. Engine concepts that use highly efficient fuel cell/electric drive technologies in hydrogen-fueled engines will be presented in the proposed paper. Carbon-dioxide emissions will be eliminated by replacing hydrocarbon fuel with hydrogen, and reduce NOx emissions through better combustion process control. A revolutionary exoskeletal engine concept, in which the engine drum is rotated, will be shown. This concept has the potential to allow a propulsion system that can be used for subsonic through hypersonic flight. Dual fan concepts that have ultra-high bypass ratios, low noise, and low drag will be presented. Flow-controlled turbofans and control-configured turbofans also will be discussed. To increase efficiency, a system of microengines distributed along lifting surfaces and on the fuselage is being investigated. This concept will be presented in the paper. Small propulsion systems for affordable, safe personal transportation vehicles will be discussed. These low-oil/oilless systems use technologies that enable significant cost and weight reductions. Pulse detonation engine-based hybrid-cycle and combined-cycle propulsion systems for aviation and space access will be presented.

Environmental and Economic Implications of Distributed Additive Manufacturing: The Case of Injection Mold Tooling: Environmental Implications of Additive Manufacturing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Runze; Riddle, Matthew E.; Graziano, Diane

Additive manufacturing (AM) holds great potentials in enabling superior engineering functionality, streamlining supply chains, and reducing life cycle impacts compared to conventional manufacturing (CM). This study estimates the net changes in supply-chain lead time, life cycle primary energy consumption, greenhouse gas (GHG) emissions, and life cycle costs (LCC) associated with AM technologies for the case of injection molding, to shed light on the environmental and economic advantages of a shift from international or onshore CM to AM in the United States. A systems modeling framework is developed, with integrations of lead-time analysis, life cycle inventory analysis, LCC model, and scenariosmore » considering design differences, supply-chain options, productions, maintenance, and AM technological developments. AM yields a reduction potential of 3% to 5% primary energy, 4% to 7% GHG emissions, 12% to 60% lead time, and 15% to 35% cost over 1 million cycles of the injection molding production depending on the AM technology advancement in future. The economic advantages indicate the significant role of AM technology in raising global manufacturing competitiveness of local producers, while the relatively small environmental benefits highlight the necessity of considering trade-offs and balance techniques between environmental and economic performances when AM is adopted in the tooling industry. The results also help pinpoint the technological innovations in AM that could lead to broader benefits in future.« less

Environmental and Economic Implications of Distributed Additive Manufacturing: The Case of Injection Mold Tooling: Environmental Implications of Additive Manufacturing

DOE PAGES

Huang, Runze; Riddle, Matthew E.; Graziano, Diane; ...

2017-08-26

Additive manufacturing (AM) holds great potentials in enabling superior engineering functionality, streamlining supply chains, and reducing life cycle impacts compared to conventional manufacturing (CM). This study estimates the net changes in supply-chain lead time, life cycle primary energy consumption, greenhouse gas (GHG) emissions, and life cycle costs (LCC) associated with AM technologies for the case of injection molding, to shed light on the environmental and economic advantages of a shift from international or onshore CM to AM in the United States. A systems modeling framework is developed, with integrations of lead-time analysis, life cycle inventory analysis, LCC model, and scenariosmore » considering design differences, supply-chain options, productions, maintenance, and AM technological developments. AM yields a reduction potential of 3% to 5% primary energy, 4% to 7% GHG emissions, 12% to 60% lead time, and 15% to 35% cost over 1 million cycles of the injection molding production depending on the AM technology advancement in future. The economic advantages indicate the significant role of AM technology in raising global manufacturing competitiveness of local producers, while the relatively small environmental benefits highlight the necessity of considering trade-offs and balance techniques between environmental and economic performances when AM is adopted in the tooling industry. The results also help pinpoint the technological innovations in AM that could lead to broader benefits in future.« less

Thermal-structural design study of an airframe-integrated Scramjet

NASA Technical Reports Server (NTRS)

Killackey, J. J.; Katinsky, E. A.; Tepper, S.; Vuigner, A. A.

1978-01-01

Design concepts are developed and evaluated for a cooled structures assembly for the Scramjet engine, for engine subsystems mass, volume, and operating requirements, and for the aircraft/engine interface. A thermal protection system was defined that makes it possible to attain a life of 100 hours and 1000 cycles. The coolant equivalence ratio at the Mach 10 maximum thermal loading condition is 0.6, indicating a capacity for airframe cooling. The mechanical design is feasible for manufacture using conventional materials. For the cooled structures in a six-module engine, the mass per unit capture area is 12.4 KN/sq m. The total weight of a six-module engine assembly including the fuel system is 14.73 KN.

Orbital transfer rocket engine technology: Advanced engine study

NASA Technical Reports Server (NTRS)

Hayden, Warren R.

1992-01-01

An advanced LOX/LH2 engine study for the use of NASA and vehicle prime contractors in developing concepts for manned missions to the Moon, Mars, and Phobos is documented. Parametric design data was obtained at five engine thrusts from 7.5K lbf to 50K lbf. Also, a separate task evaluated engine throttling over a 20:1 range and operation at a mixture ratio of 12 plus or minus 1 versus the 6 plus or minus 1 nominal. Cost data was also generated for DDT&E, first unit production, and factors in other life cycle costs. The major limitation of the study was lack of contact with vehicle prime contractors to resolve the issues in vehicle/engine interfaces. The baseline Aerojet dual propellant expander cycle was shown capable of meeting all performance requirements with an expected long operational life due to the high thermal margins. The basic engine design readily accommodated the 20:1 throttling requirement and operation up to a mixture ratio of 10 without change. By using platinum for baffled injector construction the increased thermal margin allowed operation up to mixture ratio 13. An initial engine modeling with an Aerojet transient simulation code (named MLETS) indicates stable engine operation with the baseline control system. A throttle ratio of 4 to 5 seconds from 10 percent to 100 percent thrust is also predicted. Performance predictions are 483.1 sec at 7.5K lbf, 487.3 sec at 20K lbf, and 485.2 sec at 50K lbf with a mixture ratio of 6 and an area ratio of 1200. Engine envelopes varied from 120 in. length/53 in. exit diameter at 7.5K lbf to 305 in. length/136 in. exit diameter at 50 K lbf. Packaging will be an important consideration. Continued work is recommended to include more vehicle prime contractor/engine contractor joint assessment of the interface issues.

Advanced orbit transfer vehicle propulsion system study

NASA Technical Reports Server (NTRS)

Cathcart, J. A.; Cooper, T. W.; Corringrato, R. M.; Cronau, S. T.; Forgie, S. C.; Harder, M. J.; Mcallister, J. G.; Rudman, T. J.; Stoneback, V. W.

1985-01-01

A reuseable orbit transfer vehicle concept was defined and subsequent recommendations for the design criteria of an advanced LO2/LH2 engine were presented. The major characteristics of the vehicle preliminary design include a low lift to drag aerocapture capability, main propulsion system failure criteria of fail operational/fail safe, and either two main engines with an attitude control system for backup or three main engines to meet the failure criteria. A maintenance and servicing approach was also established for the advanced vehicle and engine concepts. Design tradeoff study conclusions were based on the consideration of reliability, performance, life cycle costs, and mission flexibility.

A Closed Brayton Power Conversion Unit Concept for Nuclear Electric Propulsion for Deep Space Missions

NASA Astrophysics Data System (ADS)

Joyner, Claude Russell; Fowler, Bruce; Matthews, John

2003-01-01

In space, whether in a stable satellite orbit around a planetary body or traveling as a deep space exploration craft, power is just as important as the propulsion. The need for power is especially important for in-space vehicles that use Electric Propulsion. Using nuclear power with electric propulsion has the potential to provide increased payload fractions and reduced mission times to the outer planets. One of the critical engineering and design aspects of nuclear electric propulsion at required mission optimized power levels is the mechanism that is used to convert the thermal energy of the reactor to electrical power. The use of closed Brayton cycles has been studied over the past 30 or years and shown to be the optimum approach for power requirements that range from ten to hundreds of kilowatts of power. It also has been found to be scalable to higher power levels. The Closed Brayton Cycle (CBC) engine power conversion unit (PCU) is the most flexible for a wide range of power conversion needs and uses state-of-the-art, demonstrated engineering approaches. It also is in use with many commercial power plants today. The long life requirements and need for uninterrupted operation for nuclear electric propulsion demands high reliability from a CBC engine. A CBC engine design for use with a Nuclear Electric Propulsion (NEP) system has been defined based on Pratt & Whitney's data from designing long-life turbo-machines such as the Space Shuttle turbopumps and military gas turbines and the use of proven integrated control/health management systems (EHMS). An integrated CBC and EHMS design that is focused on using low-risk and proven technologies will over come many of the life-related design issues. This paper will discuss the use of a CBC engine as the power conversion unit coupled to a gas-cooled nuclear reactor and the design trends relative to its use for powering electric thrusters in the 25 kWe to 100kWe power level.

Industrial process system assessment: bridging process engineering and life cycle assessment through multiscale modeling.

EPA Science Inventory

The Industrial Process System Assessment (IPSA) methodology is a multiple step allocation approach for connecting information from the production line level up to the facility level and vice versa using a multiscale model of process systems. The allocation procedure assigns inpu...

The Utility of Handheld Programmable Calculators in Aircraft Life Cycle Cost Estimation.

DTIC Science & Technology

1982-09-01

are available for extended mem - ory, hardcopy printout, video interface, and special application software. Any calculator of comparable memory could...condi- tioning system. OG Total number of engine, air turbine motor (ATM) and auxiliary power unit (APU) driven generator/alternators. OHP Total number

A report on NASA software engineering and Ada training requirements

NASA Technical Reports Server (NTRS)

Legrand, Sue; Freedman, Glenn B.; Svabek, L.

1987-01-01

NASA's software engineering and Ada skill base are assessed and information that may result in new models for software engineering, Ada training plans, and curricula are provided. A quantitative assessment which reflects the requirements for software engineering and Ada training across NASA is provided. A recommended implementation plan including a suggested curriculum with associated duration per course and suggested means of delivery is also provided. The distinction between education and training is made. Although it was directed to focus on NASA's need for the latter, the key relationships to software engineering education are also identified. A rationale and strategy for implementing a life cycle education and training program are detailed in support of improved software engineering practices and the transition to Ada.

Very High Cycle Fatigue Failure Analysis and Life Prediction of Cr-Ni-W Gear Steel Based on Crack Initiation and Growth Behaviors.

PubMed

Deng, Hailong; Li, Wei; Sakai, Tatsuo; Sun, Zhenduo

2015-12-02

The unexpected failures of structural materials in very high cycle fatigue (VHCF) regime have been a critical issue in modern engineering design. In this study, the VHCF property of a Cr-Ni-W gear steel was experimentally investigated under axial loading with the stress ratio of R = -1, and a life prediction model associated with crack initiation and growth behaviors was proposed. Results show that the Cr-Ni-W gear steel exhibits the constantly decreasing S-N property without traditional fatigue limit, and the fatigue strength corresponding to 10⁸ cycles is around 485 MPa. The inclusion-fine granular area (FGA)-fisheye induced failure becomes the main failure mechanism in the VHCF regime, and the local stress around the inclusion play a key role. By using the finite element analysis of representative volume element, the local stress tends to increase with the increase of elastic modulus difference between inclusion and matrix. The predicted crack initiation life occupies the majority of total fatigue life, while the predicted crack growth life is only accounts for a tiny fraction. In view of the good agreement between the predicted and experimental results, the proposed VHCF life prediction model involving crack initiation and growth can be acceptable for inclusion-FGA-fisheye induced failure.

Material research for environmental sustainability in Thailand: current trends

PubMed Central

Niranatlumpong, Panadda; Ramangul, Nudjarin; Dulyaprapan, Pongsak; Nivitchanyong, Siriluck; Udomkitdecha, Werasak

2015-01-01

This article covers recent developments of material research in Thailand with a focus on environmental sustainability. Data on Thailand’s consumption and economic growth are briefly discussed to present a relevant snapshot of its economy. A selection of research work is classified into three topics, namely, (a) resource utilization, (b) material engineering and manufacturing, and (c) life cycle efficiency. Material technologies have been developed and implemented to reduce the consumption of materials, energy, and other valuable resources, thus reducing the burden we place on our ecological system. At the same time, product life cycle study allows us to understand the extent of the environmental impact we impart to our planet. PMID:27877788

Reliability/maintainability/testability design for dormancy

NASA Astrophysics Data System (ADS)

Seman, Robert M.; Etzl, Julius M.; Purnell, Arthur W.

1988-05-01

This document has been prepared as a tool for designers of dormant military equipment and systems. The purpose of this handbook is to provide design engineers with Reliability/Maintainability/Testability design guidelines for systems which spend significant portions of their life cycle in a dormant state. The dormant state is defined as a nonoperating mode where a system experiences very little or no electrical stress. The guidelines in this report present design criteria in the following categories: (1) Part Selection and Control; (2) Derating Practices; (3) Equipment/System Packaging; (4) Transportation and Handling; (5) Maintainability Design; (6) Testability Design; (7) Evaluation Methods for In-Plant and Field Evaluation; and (8) Product Performance Agreements. Whereever applicable, design guidelines for operating systems were included with the dormant design guidelines. This was done in an effort to produce design guidelines for a more complete life cycle. Although dormant systems spend significant portions of their life cycle in a nonoperating mode, the designer must design the system for the complete life cycle, including nonoperating as well as operating modes. The guidelines are primarily intended for use in the design of equipment composed of electronic parts and components. However, they can also be used for the design of systems which encompass both electronic and nonelectronic parts, as well as for the modification of existing systems.

Human Systems Engineering and Program Success - A Retrospective Content Analysis

DTIC Science & Technology

2016-01-01

collected from the 546 documents and entered into SPSS Statistics Version 22.0 for Windows. HSI words within the sampled doc- uments ranged from zero to...engineers. The approach used a retrospective content analysis of documents from weapon systems acquisi- tion programs, namely Major Defense Acquisition...January 2016, Vol. 23 No. 1 : 78–101 January 2016 The interaction between humans and the systems they use affects program success, as well as life-cycle

Model-Based Systems Engineering With the Architecture Analysis and Design Language (AADL) Applied to NASA Mission Operations

NASA Technical Reports Server (NTRS)

Munoz Fernandez, Michela Miche

2014-01-01

The potential of Model Model Systems Engineering (MBSE) using the Architecture Analysis and Design Language (AADL) applied to space systems will be described. AADL modeling is applicable to real-time embedded systems- the types of systems NASA builds. A case study with the Juno mission to Jupiter showcases how this work would enable future missions to benefit from using these models throughout their life cycle from design to flight operations.

Volvo Penta 4.3 GL E15 Emissions and Durability Test

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zoubul, G.; Cahoon, M.; Kolb, R.

2011-10-01

A new Volvo Penta carbureted 4.3 GL engine underwent emissions and dynamometer durability testing from break-in to expected end of life using an accelerated ICOMIA marine emissions cycle and E15 fuel. Only ethanol content was controlled. All aging used splash-blended E15 fuel. Exhaust emissions, exhaust gas temperature, torque, power, barometric pressure, air temperature, and fuel flow were measured at five intervals using site-blended E15 aging fuel and certification fuel (E0). The durability test cycle showed no noticeable impact on mechanical durability or engine power. Emissions performance degraded beyond the certification limit for this engine family, mostly occurring by 28% ofmore » expected life. Such degradation is inconsistent with prior experience. Comparisons showed that E15 resulted in lower CO and HC, but increased NOX, as expected for non-feedback-controlled carbureted engines with increased oxygen in the fuel. Fuel consumption also increased with E15 compared with E0. Throughout testing, poor starting characteristics were exhibited on E15 fuel for hot re-start and cold-start. Cranking time to start and smooth idle was roughly doubled compared with typical E0 operation. The carburetor was factory-set for lean operation to ensure emissions compliance. Test protocols did not include carburetor adjustment to account for increased oxygen in the E15 fuel.« less

The Complete Burning of Weapons Grade Plutonium and Highly Enriched Uranium with (Laser Inertial Fusion-Fission Energy) LIFE Engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farmer, J C; Diaz de la Rubia, T; Moses, E

2008-12-23

The National Ignition Facility (NIF) project, a laser-based Inertial Confinement Fusion (ICF) experiment designed to achieve thermonuclear fusion ignition and burn in the laboratory, is under construction at the Lawrence Livermore National Laboratory (LLNL) and will be completed in April of 2009. Experiments designed to accomplish the NIF's goal will commence in late FY2010 utilizing laser energies of 1 to 1.3 MJ. Fusion yields of the order of 10 to 20 MJ are expected soon thereafter. Laser initiated fusion-fission (LIFE) engines have now been designed to produce nuclear power from natural or depleted uranium without isotopic enrichment, and from spentmore » nuclear fuel from light water reactors without chemical separation into weapons-attractive actinide streams. A point-source of high-energy neutrons produced by laser-generated, thermonuclear fusion within a target is used to achieve ultra-deep burn-up of the fertile or fissile fuel in a sub-critical fission blanket. Fertile fuels including depleted uranium (DU), natural uranium (NatU), spent nuclear fuel (SNF), and thorium (Th) can be used. Fissile fuels such as low-enrichment uranium (LEU), excess weapons plutonium (WG-Pu), and excess highly-enriched uranium (HEU) may be used as well. Based upon preliminary analyses, it is believed that LIFE could help meet worldwide electricity needs in a safe and sustainable manner, while drastically shrinking the nation's and world's stockpile of spent nuclear fuel and excess weapons materials. LIFE takes advantage of the significant advances in laser-based inertial confinement fusion that are taking place at the NIF at LLNL where it is expected that thermonuclear ignition will be achieved in the 2010-2011 timeframe. Starting from as little as 300 to 500 MW of fusion power, a single LIFE engine will be able to generate 2000 to 3000 MWt in steady state for periods of years to decades, depending on the nuclear fuel and engine configuration. Because the fission blanket in a fusion-fission hybrid system is subcritical, a LIFE engine can burn any fertile or fissile nuclear material, including unenriched natural or depleted U and SNF, and can extract a very high percentage of the energy content of its fuel resulting in greatly enhanced energy generation per metric ton of nuclear fuel, as well as nuclear waste forms with vastly reduced concentrations of long-lived actinides. LIFE engines could thus provide the ability to generate vast amounts of electricity while greatly reducing the actinide content of any existing or future nuclear waste and extending the availability of low cost nuclear fuels for several thousand years. LIFE also provides an attractive pathway for burning excess weapons Pu to over 99% FIMA (fission of initial metal atoms) without the need for fabricating or reprocessing mixed oxide fuels (MOX). Because of all of these advantages, LIFE engines offer a pathway toward sustainable and safe nuclear power that significantly mitigates nuclear proliferation concerns and minimizes nuclear waste. An important aspect of a LIFE engine is the fact that there is no need to extract the fission fuel from the fission blanket before it is burned to the desired final level. Except for fuel inspection and maintenance process times, the nuclear fuel is always within the core of the reactor and no weapons-attractive materials are available outside at any point in time. However, an important consideration when discussing proliferation concerns associated with any nuclear fuel cycle is the ease with which reactor fuel can be converted to weapons usable materials, not just when it is extracted as waste, but at any point in the fuel cycle. Although the nuclear fuel remains in the core of the engine until ultra deep actinide burn up is achieved, soon after start up of the engine, once the system breeds up to full power, several tons of fissile material is present in the fission blanket. However, this fissile material is widely dispersed in millions of fuel pebbles, which can be tagged as individual accountable items, and thus made difficult to divert in large quantities. This report discusses the application of the LIFE concept to nonproliferation issues, initially looking at the LIFE (Laser Inertial Fusion-Fission Energy) engine as a means of completely burning WG Pu and HEU. By combining a neutron-rich inertial fusion point source with energy-rich fission, the once-through closed fuel-cycle LIFE concept has the following characteristics: it is capable of efficiently burning excess weapons or separated civilian plutonium and highly enriched uranium; the fission blanket is sub-critical at all times (keff < 0.95); because LIFE can operate well beyond the point at which light water reactors (LWRs) need to be refueled due to burn-up of fissile material and the resulting drop in system reactivity, fuel burn-up of 99% or more appears feasible. The objective of this work is to develop LIFE technology for burning of WG-Pu and HEU.« less

Cost/benefit studies of advanced materials technologies for future aircraft turbine engines: Materials for advanced turbine engines

NASA Technical Reports Server (NTRS)

Stearns, M.; Wilbers, L.

1982-01-01

Cost benefit studies were conducted on six advanced materials and processes technologies applicable to commercial engines planned for production in the 1985 to 1990 time frame. These technologies consisted of thermal barrier coatings for combustor and high pressure turbine airfoils, directionally solidified eutectic high pressure turbine blades, (both cast and fabricated), and mixers, tail cones, and piping made of titanium-aluminum alloys. A fabricated titanium fan blisk, an advanced turbine disk alloy with improved low cycle fatigue life, and a long-life high pressure turbine blade abrasive tip and ceramic shroud system were also analyzed. Technologies showing considerable promise as to benefits, low development costs, and high probability of success were thermal barrier coating, directionally solidified eutectic turbine blades, and abrasive-tip blades/ceramic-shroud turbine systems.

Probabilistic Analysis of Aircraft Gas Turbine Disk Life and Reliability

NASA Technical Reports Server (NTRS)

Melis, Matthew E.; Zaretsky, Erwin V.; August, Richard

1999-01-01

Two series of low cycle fatigue (LCF) test data for two groups of different aircraft gas turbine engine compressor disk geometries were reanalyzed and compared using Weibull statistics. Both groups of disks were manufactured from titanium (Ti-6Al-4V) alloy. A NASA Glenn Research Center developed probabilistic computer code Probable Cause was used to predict disk life and reliability. A material-life factor A was determined for titanium (Ti-6Al-4V) alloy based upon fatigue disk data and successfully applied to predict the life of the disks as a function of speed. A comparison was made with the currently used life prediction method based upon crack growth rate. Applying an endurance limit to the computer code did not significantly affect the predicted lives under engine operating conditions. Failure location prediction correlates with those experimentally observed in the LCF tests. A reasonable correlation was obtained between the predicted disk lives using the Probable Cause code and a modified crack growth method for life prediction. Both methods slightly overpredict life for one disk group and significantly under predict it for the other.

Fate and transformation of graphene oxide in marine systems

EPA Science Inventory

Graphene oxide (GO) may be released into natural waters at different phases of its life cycle. Currently, there is no study on the fate of GO in seawater, which is predicted to be a major sink for many engineered nanomaterials. In this study, the influences of salinity (0-50 &per...

Software metrics: Software quality metrics for distributed systems. [reliability engineering

NASA Technical Reports Server (NTRS)

Post, J. V.

1981-01-01

Software quality metrics was extended to cover distributed computer systems. Emphasis is placed on studying embedded computer systems and on viewing them within a system life cycle. The hierarchy of quality factors, criteria, and metrics was maintained. New software quality factors were added, including survivability, expandability, and evolvability.

Structures performance, benefit, cost-study

NASA Technical Reports Server (NTRS)

Woike, O. G.; Salemme, C.; Stearns, E.; Oritz, P.; Roberts, M. L.; Baughman, J. L.; Johnston, R. P.; Demel, H. F.; Stabrylla, R. G.; Coffinberry, G. A.

1981-01-01

New technology concepts and structural analysis development needs which could lead to improved life cycle cost for future high-bypass turbofans were studied. The NASA-GE energy efficient engine technology is used as a base to assess the concept benefits. Recommended programs are identified for attaining these generic structural and other beneficial technologies.

Aerospace System Unified Life Cycle Engineering Producibility Measurement Issues

DTIC Science & Technology

1989-05-01

Control .................................................................. 11-9 5 . C o st...in the development process; these computer -aided models offer clarity approaching that of a prototype model. Once a part geometry is represented...of part geometry , allowing manufacturability evaluation and possibly other computer -integrated manufacturing (CIM) tasks. (Other papers that discuss

Review of Battery Technologies for Military Land Vehicles

DTIC Science & Technology

2017-01-01

be fast charged (to minimise engine-on time during silent watch operations), cycle life, cost, safety, and the effect of temperature . In addition...4 3.2 Effect of Temperature ... temperature [4]. These effects are reversed for lower discharge rates. UNCLASSIFIED DST-Group-TN-1597 UNCLASSIFIED 5 3.2 Effect of

Capstone Report - The Technology Readiness of Alternative Fuels : Alternative Fuels & Life-Cycle Engineering Program : November 29, 2006 to November 28, 2011

DOT National Transportation Integrated Search

2011-12-20

The Assistant Secretary of Defense for Networks and Information Integration (ASD/NII) and the Under Secretary of Transportation for Policy (UST/P) sponsored a National Positioning, Navigation, and Timing (PNT) Architecture Study to "provide more effe...

Advanced single crystal for SSME turbopumps

NASA Technical Reports Server (NTRS)

Fritzemeier, L. G.

1989-01-01

The objective of this program was to evaluate the influence of high thermal gradient casting, hot isostatic pressing (HIP) and alternate heat treatments on the microstructure and mechanical properties of a single crystal nickel base superalloy. The alloy chosen for the study was PWA 1480, a well characterized, commercial alloy which had previously been chosen as a candidate for the Space Shuttle Main Engine high pressure turbopump turbine blades. Microstructural characterization evaluated the influence of casting thermal gradient on dendrite arm spacing, casting porosity distribution and alloy homogeneity. Hot isostatic pressing was evaluated as a means of eliminating porosity as a preferred fatigue crack initiation site. The alternate heat treatment was chosen to improve hydrogen environment embrittlement resistance and for potential fatigue life improvement. Mechanical property evaluation was aimed primarily at determining improvements in low cycle and high cycle fatigue life due to the advanced processing methods. Statistically significant numbers of tests were conducted to quantitatively demonstrate life differences. High thermal gradient casting improves as-cast homogeneity, which facilitates solution heat treatment of PWA 1480 and provides a decrease in internal pore size, leading to increases in low cycle and high cycle fatigue lives.

Architecture and Integration Requirements for an ULCE (Unified Life Cycle Engineering) Design Environment.

DTIC Science & Technology

1988-04-01

Locate brake lines on rear side of the gear structure to prevent damage. * Provide emergency brake system , independent of the normal system , and capable of...stopping the aircraft in the same distance as the normal system . -.. * Consider brake temperature in calculating brake energy capability. * Install a...and takeoff. In addition, assume a brake nearing the end of its recommended life. - Antiskid systems shall be as reliable as the rest of the braking

Life prediction modeling based on cyclic damage accumulation

NASA Technical Reports Server (NTRS)

Nelson, Richard S.

1988-01-01

A high temperature, low cycle fatigue life prediction method was developed. This method, Cyclic Damage Accumulation (CDA), was developed for use in predicting the crack initiation lifetime of gas turbine engine materials, where initiation was defined as a 0.030 inch surface length crack. A principal engineering feature of the CDA method is the minimum data base required for implementation. Model constants can be evaluated through a few simple specimen tests such as monotonic loading and rapic cycle fatigue. The method was expanded to account for the effects on creep-fatigue life of complex loadings such as thermomechanical fatigue, hold periods, waveshapes, mean stresses, multiaxiality, cumulative damage, coatings, and environmental attack. A significant data base was generated on the behavior of the cast nickel-base superalloy B1900+Hf, including hundreds of specimen tests under such loading conditions. This information is being used to refine and extend the CDA life prediction model, which is now nearing completion. The model is also being verified using additional specimen tests on wrought INCO 718, and the final version of the model is expected to be adaptable to most any high-temperature alloy. The model is currently available in the form of equations and related constants. A proposed contract addition will make the model available in the near future in the form of a computer code to potential users.

Fatigue and durability of Nitinol stents.

PubMed

Pelton, A R; Schroeder, V; Mitchell, M R; Gong, Xiao-Yan; Barney, M; Robertson, S W

2008-04-01

Nitinol self-expanding stents are effective in treating peripheral artery disease, including the superficial femoral, carotid, and renal arteries. However, fracture occurrences of up to 50% have been reported in some stents after one year. These stent fractures are likely due to in vivo cyclic displacements. As such, the cyclic fatigue and durability properties of Nitinol-based endovascular stents are discussed in terms of an engineering-based experimental testing program. In this paper, the combined effects of cardiac pulsatile fatigue and stent-vessel oversizing are evaluated for application to both stents and stent subcomponents. In particular, displacement-controlled fatigue tests were performed on stent-like specimens processed from Nitinol microtubing. Fatigue data were collected with combinations of simulated oversizing conditions and pulsatile cycles that were identified by computer modeling of the stent that mimic in vivo deformation conditions. These data are analyzed with non-linear finite element computations and are illustrated with strain-life and strain-based constant-life diagrams. The utility of this approach is demonstrated in conjunction with 10 million cycle pulsatile fatigue tests of Cordis SMART Control((R)) Nitinol self-expanding stents to calculate fatigue safety factors and thereby predict in vivo fatigue resistance. These results demonstrate the non-linear constant fatigue-life response of Nitinol stents, whereby, contrary to conventional engineering materials, the fatigue life of Nitinol is observed to increase with increasing mean strain.

Design Guidance for Command, Control, Communications, and Intelligence (C3I) Facility Cooling Systems

DTIC Science & Technology

1989-05-01

Typical ranges are from 50 to 70 OF. If a chiller is dedicated to serving water-cooled electronic equipment, the chilled water temperature setpoint can...can be satisfied with 50 OF chilled water. The COP of the dedicated chiller is improved by raising the chilled water setpoint , and the total life-cycle...USACERL TECHNICAL REPORT E-89/10 May 1989 Studies in Optimizing HVAC Hardware for C31 Facilities US Army Corps of Engineers Construction Engineering

Models and metrics for software management and engineering

NASA Technical Reports Server (NTRS)

Basili, V. R.

1988-01-01

This paper attempts to characterize and present a state of the art view of several quantitative models and metrics of the software life cycle. These models and metrics can be used to aid in managing and engineering software projects. They deal with various aspects of the software process and product, including resources allocation and estimation, changes and errors, size, complexity and reliability. Some indication is given of the extent to which the various models have been used and the success they have achieved.

Fatigue Failure of Space Shuttle Main Engine Turbine Blades

NASA Technical Reports Server (NTRS)

Swanson, Gregrory R.; Arakere, Nagaraj K.

2000-01-01

Experimental validation of finite element modeling of single crystal turbine blades is presented. Experimental results from uniaxial high cycle fatigue (HCF) test specimens and full scale Space Shuttle Main Engine test firings with the High Pressure Fuel Turbopump Alternate Turbopump (HPFTP/AT) provide the data used for the validation. The conclusions show the significant contribution of the crystal orientation within the blade on the resulting life of the component, that the analysis can predict this variation, and that experimental testing demonstrates it.

Developing the JPL Engineering Processes

NASA Technical Reports Server (NTRS)

Linick, Dave; Briggs, Clark

2004-01-01

This paper briefly recounts the recent history of process reengineering at the NASA Jet Propulsion Laboratory, with a focus on the engineering processes. The JPL process structure is described and the process development activities of the past several years outlined. The main focus of the paper is on the current process structure, the emphasis on the flight project life cycle, the governance approach that lead to Flight Project Practices, and the remaining effort to capture process knowledge at the detail level of the work group.

Engineering Design Handbook: Environmental Series. Part Four. Life Cycle Environments

DTIC Science & Technology

1975-03-31

Natick Laboratories, Natick, Mass., De - ment of Defense Directive 4120.3, Wash- cember 1968. ington, D C, 13 January 1967. 3. Dictionary of Military and...Series of However. no concerted effort has been made Engineering Design Handbooks contains de - to identify combinations of factors that are scriptions...over during a period of 3 hr 10 min., 22 JanuaryW4V Greatest rainfall 1. World: Unionville, Md.; 1.23 in. in I min, 4 July 1956 2. World: Curtea- de

Integrating post-manufacturing issues into design and manufacturing decisions

NASA Technical Reports Server (NTRS)

Eubanks, Charles F.

1996-01-01

An investigation is conducted on research into some of the fundamental issues underlying the design for manufacturing, service and recycling that affect engineering decisions early in the conceptual design phase of mechanical systems. The investigation focuses on a system-based approach to material selection, manufacturing methods and assembly processes related to overall product requirements, performance and life-cycle costs. Particular emphasis is placed on concurrent engineering decision support for post-manufacturing issues such as serviceability, recyclability, and product retirement.

Study on the financing mechanism and management for decommissioning of nuclear installations in Malaysia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saleh, Lydia Ilaiza, E-mail: lydiailaiza@gmail.com; Ryong, Kim Tae

The whole cycle of the decommissioning process development of repository requires the relevant bodies to have a financial system to ensure that it has sufficient funds for its whole life cycle (over periods of many decades). Therefore, the financing mechanism and management system shall respect the following status: the national position, institutional and legislative environment, technical capabilities, the waste origin, ownership, characteristics and inventories. The main objective of the studies is to focus on the cost considerations, alternative funding managements and mechanisms, technical and non-technical factors that may affect the repository life-cycle costs. As a conclusion, the outcomes of thismore » paper is to make a good recommendation and could be applied to the national planners, regulatory body, engineers, or the managers, to form a financial management plan for the decommissioning of the Nuclear Installation.« less

Thermally regenerative hydrogen/oxygen fuel cell power cycles

NASA Technical Reports Server (NTRS)

Morehouse, J. H.

1986-01-01

Two innovative thermodynamic power cycles are analytically examined for future engineering feasibility. The power cycles use a hydrogen-oxygen fuel cell for electrical energy production and use the thermal dissociation of water for regeneration of the hydrogen and oxygen. The TDS (thermal dissociation system) uses a thermal energy input at over 2000 K to thermally dissociate the water. The other cycle, the HTE (high temperature electrolyzer) system, dissociates the water using an electrolyzer operating at high temperature (1300 K) which receives its electrical energy from the fuel cell. The primary advantages of these cycles is that they are basically a no moving parts system, thus having the potential for long life and high reliability, and they have the potential for high thermal efficiency. Both cycles are shown to be classical heat engines with ideal efficiency close to Carnot cycle efficiency. The feasibility of constructing actual cycles is investigated by examining process irreversibilities and device efficiencies for the two types of cycles. The results show that while the processes and devices of the 2000 K TDS exceed current technology limits, the high temperature electrolyzer system appears to be a state-of-the-art technology development. The requirements for very high electrolyzer and fuel cell efficiencies are seen as determining the feasbility of the HTE system, and these high efficiency devices are currently being developed. It is concluded that a proof-of-concept HTE system experiment can and should be conducted.

Computerized systems analysis and optimization of aircraft engine performance, weight, and life cycle costs

NASA Technical Reports Server (NTRS)

Fishbach, L. H.

1979-01-01

The paper describes the computational techniques employed in determining the optimal propulsion systems for future aircraft applications and to identify system tradeoffs and technology requirements. The computer programs used to perform calculations for all the factors that enter into the selection process of determining the optimum combinations of airplanes and engines are examined. Attention is given to the description of the computer codes including NNEP, WATE, LIFCYC, INSTAL, and POD DRG. A process is illustrated by which turbine engines can be evaluated as to fuel consumption, engine weight, cost and installation effects. Examples are shown as to the benefits of variable geometry and of the tradeoff between fuel burned and engine weights. Future plans for further improvements in the analytical modeling of engine systems are also described.

Suggested criteria for evaluating systems engineering methodologies

NASA Technical Reports Server (NTRS)

Gates, Audrey; Paul, Arthur S.; Gill, Tepper L.

1989-01-01

Systems engineering is the application of mathematical and scientific principles to practical ends in the life-cycle of a system. A methodology for systems engineering is a carefully developed, relatively complex procedure or process for applying these mathematical and scientific principles. There are many systems engineering methodologies (or possibly many versions of a few methodologies) currently in use in government and industry. These methodologies are usually designed to meet the needs of a particular organization. It has been observed, however, that many technical and non-technical problems arise when inadequate systems engineering methodologies are applied by organizations to their systems development projects. Various criteria for evaluating systems engineering methodologies are discussed. Such criteria are developed to assist methodology-users in identifying and selecting methodologies that best fit the needs of the organization.

Space shuttle main engine: Interactive design challenges

NASA Technical Reports Server (NTRS)

Mccarty, J. P.; Wood, B. K.

1985-01-01

The operating requirements established by NASA for the SSME were considerably more demanding than those for earlier rocket engines used in the military launch vehicles or Apollo program. The SSME, in order to achieve the high performance, low weight, long life, reusable objectives, embodied technical demands far in excess of its predecessor rocket engines. The requirements dictated the use of high combustion pressure and the staged combustion cycle which maximizes performance through total use of all propellants in the main combustion process. This approach presented a myriad of technical challenges for maximization of performance within attainable state of the art capabilities for operating pressures, operating temperatures and rotating machinery efficiencies. Controlling uniformity of the high pressure turbomachinery turbine temperature environment was a key challenge for thrust level and life capability demanding innovative engineering. New approaches in the design of the components were necessary to accommodate the multiple use, minimum maintenance objectives. Included were the use of line replaceable units to facilitate field maintenance automatic checkout and internal inspection capabilities.

Design tradeoff studies and sensitivity analysis, appendix B

NASA Technical Reports Server (NTRS)

1979-01-01

Further work was performed on the Near Term Hybrid Passenger Vehicle Development Program. Fuel economy on the order of 2 to 3 times that of a conventional vehicle, with a comparable life cycle cost, is possible. The two most significant factors in keeping the life cycle cost down are the retail price increment and the ratio of battery replacement cost to battery life. Both factors can be reduced by reducing the power rating of the electric drive portion of the system relative to the system power requirements. The type of battery most suitable for the hybrid, from the point of view of minimizing life cycle cost, is nickel-iron. The hybrid is much less sensitive than a conventional vehicle is, in terms of the reduction in total fuel consumption and resultant decreases in operating expense, to reductions in vehicle weight, tire rolling resistance, etc., and to propulsion system and drivetrain improvements designed to improve the brake specific fuel consumption of the engine under low road load conditions. It is concluded that modifications to package the propulsion system and battery pack can be easily accommodated within the confines of a modified carryover body such as the Ford Ltd.

Systems Engineering Provides Successful High Temperature Steam Electrolysis Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Charles V. Park; Emmanuel Ohene Opare, Jr.

2011-06-01

This paper describes two Systems Engineering Studies completed at the Idaho National Laboratory (INL) to support development of the High Temperature Stream Electrolysis (HTSE) process. HTSE produces hydrogen from water using nuclear power and was selected by the Department of Energy (DOE) for integration with the Next Generation Nuclear Plant (NGNP). The first study was a reliability, availability and maintainability (RAM) analysis to identify critical areas for technology development based on available information regarding expected component performance. An HTSE process baseline flowsheet at commercial scale was used as a basis. The NGNP project also established a process and capability tomore » perform future RAM analyses. The analysis identified which components had the greatest impact on HTSE process availability and indicated that the HTSE process could achieve over 90% availability. The second study developed a series of life-cycle cost estimates for the various scale-ups required to demonstrate the HTSE process. Both studies were useful in identifying near- and long-term efforts necessary for successful HTSE process deployment. The size of demonstrations to support scale-up was refined, which is essential to estimate near- and long-term cost and schedule. The life-cycle funding profile, with high-level allocations, was identified as the program transitions from experiment scale R&D to engineering scale demonstration.« less

Integrated Logistics Support approach: concept for the new big projects: E-ELT, SKA, CTA

NASA Astrophysics Data System (ADS)

Marchiori, G.; Rampini, F.; Formentin, F.

2014-08-01

The Integrated Logistic Support is a process supporting strategies and optimizing activities for a correct project management and system engineering development. From the design & engineering of complex technical systems, to the erection on site, acceptance and after-sales service, EIE GROUP covers all aspects of the Integrated Logistics Support (ILS) process that includes: costing process centered around the life cycle cost and Level of Repair Analyses; engineering process which influences the design via means of reliability, modularization, etc.; technical publishing process based on international specifications; ordering administration process for supply support. Through the ILS, EIE GROUP plans and directs the identification and development of logistics support and system requirements for its products, with the goal of creating systems that last longer and require less support, thereby reducing costs and increasing return on investments. ILS therefore, addresses these aspects of supportability not only during acquisition, but also throughout the operational life cycle of the system. The impact of the ILS is often measured in terms of metrics such as reliability, availability, maintainability and testability (RAMT), and System Safety (RAMS). Example of the criteria and approach adopted by EIE GROUP during the design, manufacturing and test of the ALMA European Antennas and during the design phase of the E-ELT telescope and Dome are presented.

Life cycle analysis of vehicles powered by a fuel cell and by internal combustion engine for Canada

NASA Astrophysics Data System (ADS)

Zamel, Nada; Li, Xianguo

The transportation sector is responsible for a great percentage of the greenhouse gas emissions as well as the energy consumption in the world. Canada is the second major emitter of carbon dioxide in the world. The need for alternative fuels, other than petroleum, and the need to reduce energy consumption and greenhouse gases emissions are the main reasons behind this study. In this study, a full life cycle analysis of an internal combustion engine vehicle (ICEV) and a fuel cell vehicle (FCV) has been carried out. The impact of the material and fuel used in the vehicle on energy consumption and carbon dioxide emissions is analyzed for Canada. The data collected from the literature shows that the energy consumption for the production of 1 kg of aluminum is five times higher than that of 1 kg of steel, although higher aluminum content makes vehicles lightweight and more energy efficient during the vehicle use stage. Greenhouse gas regulated emissions and energy use in transportation (GREET) software has been used to analyze the fuel life cycle. The life cycle of the fuel consists of obtaining the raw material, extracting the fuel from the raw material, transporting, and storing the fuel as well as using the fuel in the vehicle. Four different methods of obtaining hydrogen were analyzed; using coal and nuclear power to produce electricity and extraction of hydrogen through electrolysis and via steam reforming of natural gas in a natural gas plant and in a hydrogen refueling station. It is found that the use of coal to obtain hydrogen generates the highest emissions and consumes the highest energy. Comparing the overall life cycle of an ICEV and a FCV, the total emissions of an FCV are 49% lower than an ICEV and the energy consumption of FCV is 87% lower than that of ICEV. Further, CO 2 emissions during the hydrogen fuel production in a central plant can be easily captured and sequestrated. The comparison carried out in this study between FCV and ICEV is extended to the use of recycled material. It is found that using 100% recycled material can reduce energy consumption by 45% and carbon dioxide emissions by 42%, mainly due to the reduced use of electricity during the manufacturing of the material.

A program-level management system for the life cycle environmental and economic assessment of complex building projects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Chan-Joong; Kim, Jimin; Hong, Taehoon

Climate change has become one of the most significant environmental issues, of which about 40% come from the building sector. In particular, complex building projects with various functions have increased, which should be managed from a program-level perspective. Therefore, this study aimed to develop a program-level management system for the life-cycle environmental and economic assessment of complex building projects. The developed system consists of three parts: (i) input part: database server and input data; (ii) analysis part: life cycle assessment and life cycle cost; and (iii) result part: microscopic analysis and macroscopic analysis. To analyze the applicability of the developedmore » system, this study selected ‘U’ University, a complex building project consisting of research facility and residential facility. Through value engineering with experts, a total of 137 design alternatives were established. Based on these alternatives, the macroscopic analysis results were as follows: (i) at the program-level, the life-cycle environmental and economic cost in ‘U’ University were reduced by 6.22% and 2.11%, respectively; (ii) at the project-level, the life-cycle environmental and economic cost in research facility were reduced 6.01% and 1.87%, respectively; and those in residential facility, 12.01% and 3.83%, respective; and (iii) for the mechanical work at the work-type-level, the initial cost was increased 2.9%; but the operation and maintenance phase was reduced by 20.0%. As a result, the developed system can allow the facility managers to establish the operation and maintenance strategies for the environmental and economic aspects from a program-level perspective. - Highlights: • A program-level management system for complex building projects was developed. • Life-cycle environmental and economic assessment can be conducted using the system. • The design alternatives can be analyzed from the microscopic perspective. • The system can be used to establish the optimal O&M strategy at the program-level. • It can be applied to any other country or sector in the global environment.« less

Synthetic biology meets tissue engineering.

PubMed

Davies, Jamie A; Cachat, Elise

2016-06-15

Classical tissue engineering is aimed mainly at producing anatomically and physiologically realistic replacements for normal human tissues. It is done either by encouraging cellular colonization of manufactured matrices or cellular recolonization of decellularized natural extracellular matrices from donor organs, or by allowing cells to self-organize into organs as they do during fetal life. For repair of normal bodies, this will be adequate but there are reasons for making unusual, non-evolved tissues (repair of unusual bodies, interface to electromechanical prostheses, incorporating living cells into life-support machines). Synthetic biology is aimed mainly at engineering cells so that they can perform custom functions: applying synthetic biological approaches to tissue engineering may be one way of engineering custom structures. In this article, we outline the 'embryological cycle' of patterning, differentiation and morphogenesis and review progress that has been made in constructing synthetic biological systems to reproduce these processes in new ways. The state-of-the-art remains a long way from making truly synthetic tissues, but there are now at least foundations for future work. © 2016 Authors; published by Portland Press Limited.

Free-piston Stirling engine/linear alternator 1000-hour endurance test

NASA Technical Reports Server (NTRS)

Rauch, J.; Dochat, G.

1985-01-01

The Free Piston Stirling Engine (FPSE) has the potential to be a long lived, highly reliable, power conversion device attractive for many product applications such as space, residential or remote site power. The purpose of endurance testing the FPSE was to demonstrate its potential for long life. The endurance program was directed at obtaining 1000 operational hours under various test conditions: low power, full stroke, duty cycle and stop/start. Critical performance parameters were measured to note any change and/or trend. Inspections were conducted to measure and compare critical seal/bearing clearances. The engine performed well throughout the program, completing more than 1100 hours. Hardware inspection, including the critical clearances, showed no significant change in hardware or clearance dimensions. The performance parameters did not exhibit any increasing or decreasing trends. The test program confirms the potential for long life FPSE applications.

A supply chain approach to biochar systems [Chapter 2

Treesearch

Nathaniel M. Anderson; Richard D. Bergman; Deborah S. Page-Dumroese

2017-01-01

Biochar systems are designed to meet four related primary objectives: improve soils, manage waste, generate renewable energy, and mitigate climate change. Supply chain models provide a holistic framework for examining biochar systems with an emphasis on product life cycle and end use. Drawing on concepts in supply chain management and engineering, this chapter presents...

Towards Model-Driven End-User Development in CALL

ERIC Educational Resources Information Center

Farmer, Rod; Gruba, Paul

2006-01-01

The purpose of this article is to introduce end-user development (EUD) processes to the CALL software development community. EUD refers to the active participation of end-users, as non-professional developers, in the software development life cycle. Unlike formal software engineering approaches, the focus in EUD on means/ends development is…

Students' Perceptions of BIM Education in the Higher Education Sector: A UK and US Perspective

ERIC Educational Resources Information Center

Shelbourn, M.; Macdonald, J.; McCuen, T.; Lee, S.

2017-01-01

The use of building information modelling (BIM) has increased in the global architecture, engineering, construction and owner-operated (AECO) industries. This increased use has contributed to a recognition by project stakeholders of its importance across the building life cycle, leading higher education institutions to rethink their AECO…

Engineering Greener Processes--Laser Cutter Transforms Printing Waste

ERIC Educational Resources Information Center

Xu, Renmei; Flowers, Jim

2011-01-01

Many of today's students have embraced an environmental ethic and are motivated by efforts to reduce waste or to remanufacture waste into viable products. In-class efforts to reuse and remanufacture waste can be especially motivating. They can also help students develop a better understanding of life-cycle analysis, waste-stream management,…

Argonne Chemical Sciences & Engineering - Center for Electrical Energy

Science.gov Websites

electrodes at the SEI interface, Li-ion batteries show limited calendar and cycle life--less than 2 years energy storage requirements. The CEES will focus on lithium batteries, as they offer the best opportunity of Argonne's Applied Battery Research and Development Program. EFRCs at Argonne The Center for

Development and fabrication of structural components for a scramjet engine

NASA Technical Reports Server (NTRS)

Buchmann, O. A.

1990-01-01

A program broadly directed toward design and development of long-life (100 hours and 1,000 cycles with a goal of 1,000 hours and 10,000 cycles) hydrogen-cooled structures for application to scramjets is presented. Previous phases of the program resulted in an overall engine design and analytical and experimental characterization of selected candidate materials and concepts. The latter efforts indicated that the basic life goals for the program can be reached with available means. The main objective of this effort was an integrated, experimental evaluation of the results of the previous program phases. The fuel injection strut was selected for this purpose, including fabrication development and fabrication of a full-scale strut. Testing of the completed strut was to be performed in a NASA-Langley wind tunnel. In addition, conceptual designs were formulated for a heat transfer test unit and a flat panel structural test unit. Tooling and fabrication procedures required to fabricate the strut were developed, and fabrication and delivery to NASA of all strut components, including major subassemblies, were completed.

Probabilistic framework for product design optimization and risk management

NASA Astrophysics Data System (ADS)

Keski-Rahkonen, J. K.

2018-05-01

Probabilistic methods have gradually gained ground within engineering practices but currently it is still the industry standard to use deterministic safety margin approaches to dimensioning components and qualitative methods to manage product risks. These methods are suitable for baseline design work but quantitative risk management and product reliability optimization require more advanced predictive approaches. Ample research has been published on how to predict failure probabilities for mechanical components and furthermore to optimize reliability through life cycle cost analysis. This paper reviews the literature for existing methods and tries to harness their best features and simplify the process to be applicable in practical engineering work. Recommended process applies Monte Carlo method on top of load-resistance models to estimate failure probabilities. Furthermore, it adds on existing literature by introducing a practical framework to use probabilistic models in quantitative risk management and product life cycle costs optimization. The main focus is on mechanical failure modes due to the well-developed methods used to predict these types of failures. However, the same framework can be applied on any type of failure mode as long as predictive models can be developed.

Life Cycle Cost Analysis of Ready Mix Concrete Plant

NASA Astrophysics Data System (ADS)

Topkar, V. M.; Duggar, A. R.; Kumar, A.; Bonde, P. P.; Girwalkar, R. S.; Gade, S. B.

2013-11-01

India, being a developing nation is experiencing major growth in its infrastructural sector. Concrete is the major component in construction. The requirement of good quality of concrete in large quantities can be fulfilled by ready mix concrete batching and mixing plants. The paper presents a technique of applying the value engineering tool life cycle cost analysis to a ready mix concrete plant. This will help an investor or an organization to take investment decisions regarding a ready mix concrete facility. No economic alternatives are compared in this study. A cost breakdown structure is prepared for the ready mix concrete plant. A market survey has been conducted to collect realistic costs for the ready mix concrete facility. The study establishes the cash flow for the ready mix concrete facility helpful in investment and capital generation related decisions. Transit mixers form an important component of the facility and are included in the calculations. A fleet size for transit mixers has been assumed for this purpose. The life cycle cost has been calculated for the system of the ready mix concrete plant and transit mixers.

Some key considerations in evolving a computer system and software engineering support environment for the space station program

NASA Technical Reports Server (NTRS)

Mckay, C. W.; Bown, R. L.

1985-01-01

The space station data management system involves networks of computing resources that must work cooperatively and reliably over an indefinite life span. This program requires a long schedule of modular growth and an even longer period of maintenance and operation. The development and operation of space station computing resources will involve a spectrum of systems and software life cycle activities distributed across a variety of hosts, an integration, verification, and validation host with test bed, and distributed targets. The requirement for the early establishment and use of an apporopriate Computer Systems and Software Engineering Support Environment is identified. This environment will support the Research and Development Productivity challenges presented by the space station computing system.

Engineering Lessons Learned and Systems Engineering Applications

NASA Technical Reports Server (NTRS)

Gill, Paul S.; Garcia, Danny; Vaughan, William W.

2005-01-01

Systems Engineering is fundamental to good engineering, which in turn depends on the integration and application of engineering lessons learned. Thus, good Systems Engineering also depends on systems engineering lessons learned from within the aerospace industry being documented and applied. About ten percent of the engineering lessons learned documented in the NASA Lessons Learned Information System are directly related to Systems Engineering. A key issue associated with lessons learned datasets is the communication and incorporation of this information into engineering processes. As part of the NASA Technical Standards Program activities, engineering lessons learned datasets have been identified from a number of sources. These are being searched and screened for those having a relation to Technical Standards. This paper will address some of these Systems Engineering Lessons Learned and how they are being related to Technical Standards within the NASA Technical Standards Program, including linking to the Agency's Interactive Engineering Discipline Training Courses and the life cycle for a flight vehicle development program.

Technical and economic study of Stirling and Rankine cycle bottoming systems for heavy truck diesel engines

NASA Technical Reports Server (NTRS)

Kubo, I.

1987-01-01

Bottoming cycle concepts for heavy duty transport engine applications were studied. In particular, the following tasks were performed: (1) conceptual design and cost data development for Stirling systems; (2) life-cycle cost evaluation of three bottoming systems - organic Rankine, steam Rankine, and Stirling cycles; and (3) assessment of future directions in waste heat utilization research. Variables considered for the second task were initial capital investments, fuel savings, depreciation tax benefits, salvage values, and service/maintenance costs. The study shows that none of the three bottoming systems studied are even marginally attractive. Manufacturing costs have to be reduced by at least 65%. As a new approach, an integrated Rankine/Diesel system was proposed. It utilizes one of the diesel cylinders as an expander and capitalizes on the in-cylinder heat energy. The concept eliminates the need for the power transmission device and a sophisticated control system, and reduces the size of the exhaust evaporator. Results of an economic evaluation indicate that the system has the potential to become an attractive package for end users.

Multi-Disciplinary Analysis for Future Launch Systems Using NASA's Advanced Engineering Environment (AEE)

NASA Technical Reports Server (NTRS)

Monell, D.; Mathias, D.; Reuther, J.; Garn, M.

2003-01-01

A new engineering environment constructed for the purposes of analyzing and designing Reusable Launch Vehicles (RLVs) is presented. The new environment has been developed to allow NASA to perform independent analysis and design of emerging RLV architectures and technologies. The new Advanced Engineering Environment (AEE) is both collaborative and distributed. It facilitates integration of the analyses by both vehicle performance disciplines and life-cycle disciplines. Current performance disciplines supported include: weights and sizing, aerodynamics, trajectories, propulsion, structural loads, and CAD-based geometries. Current life-cycle disciplines supported include: DDT&E cost, production costs, operations costs, flight rates, safety and reliability, and system economics. Involving six NASA centers (ARC, LaRC, MSFC, KSC, GRC and JSC), AEE has been tailored to serve as a web-accessed agency-wide source for all of NASA's future launch vehicle systems engineering functions. Thus, it is configured to facilitate (a) data management, (b) automated tool/process integration and execution, and (c) data visualization and presentation. The core components of the integrated framework are a customized PTC Windchill product data management server, a set of RLV analysis and design tools integrated using Phoenix Integration's Model Center, and an XML-based data capture and transfer protocol. The AEE system has seen production use during the Initial Architecture and Technology Review for the NASA 2nd Generation RLV program, and it continues to undergo development and enhancements in support of its current main customer, the NASA Next Generation Launch Technology (NGLT) program.

Life prediction of materials exposed to monotonic and cyclic loading: Bibliography

NASA Technical Reports Server (NTRS)

Carpenter, J. L., Jr.; Moya, N.; Stuhrke, W. F.

1975-01-01

This bibliography is comprised of approximately 1200 reference citations related to the mechanics of failure in aerospace structures. Most of the references are for information on life prediction for materials exposed to monotonic and cyclic loading in elevated temperature environments such as that in the hot end of a gas turbine engine. Additional citations listed are for documents on the thermal and mechanical effects on solar cells in the cryogenic vacuum environment; radiation effects on high temperature mechanical properties; and high cycle fatigue technology as applicable to gas turbine engine bearings. The bibliography represents a search of the literature published in the period April 1962 through April 1974 and is largely limited to documents published in the United States. It is a companion volume to NASA CR-134750, Life Prediction of Materials Exposed to Monotonic and cyclic Loading - A Technology Survey.

Adhesive and Protective Characteristics of Ceramic Coating A-417 and Its Effect on Engine Life of Forged Refractaloy-26 (AMS 5760) and Cast Stellite 21 (AMS 5385) Turbine Blades

NASA Technical Reports Server (NTRS)

Garrett, Floyd B; Gyorgak, Charles A

1953-01-01

The adhesive and protective characteristics of National Bureau of Standards Coating A-417 were investigated, as well as the effect of the coating on the life of forged Refractaloy 26 and cast Stellite 21 turbine blades. Coated and uncoated blades were run in a full-scale J33-9 engine and were subjected to simulated service operations consisting of consecutive 20-minute cycles (15 min at rated speed and approximately 5 min at idle). The ceramic coating adhered well to Refractaloy 26 and Stellite 21 turbine blades operated at 1500 degrees F. The coating also prevented corrosion of the Refractaloy 26, a corrosion-sensitive nickel-base alloy, and of the Stellite 21, a relatively corrosion-resistant cobalt-base alloy. Although the coating prevented corrosion of both alloys, it had no apparent effect on blade life.

Computer-assisted engineering data base

NASA Technical Reports Server (NTRS)

Dube, R. P.; Johnson, H. R.

1983-01-01

General capabilities of data base management technology are described. Information requirements posed by the space station life cycle are discussed, and it is asserted that data base management technology supporting engineering/manufacturing in a heterogeneous hardware/data base management system environment should be applied to meeting these requirements. Today's commercial systems do not satisfy all of these requirements. The features of an R&D data base management system being developed to investigate data base management in the engineering/manufacturing environment are discussed. Features of this system represent only a partial solution to space station requirements. Areas where this system should be extended to meet full space station information management requirements are discussed.

The impact of emerging technologies on an advanced supersonic transport

NASA Technical Reports Server (NTRS)

Driver, C.; Maglieri, D. J.

1986-01-01

The effects of advances in propulsion systems, structure and materials, aerodynamics, and systems on the design and development of supersonic transport aircraft are analyzed. Efficient propulsion systems with variable-cycle engines provide the basis for improved propulsion systems; the propulsion efficienies of supersonic and subsonic engines are compared. Material advances consist of long-life damage-tolerant structures, advanced material development, aeroelastic tailoring, and low-cost fabrication. Improvements in the areas of aerodynamics and systems are examined. The environmental problems caused by engine emissions, airport noise, and sonic boom are studied. The characteristics of the aircraft designed to include these technical advances are described.

Testing of Composite Fan Vanes With Erosion-Resistant Coating Accelerated

NASA Technical Reports Server (NTRS)

Bowman, Cheryl L.; Sutter, James K.; Otten, Kim D.; Samorezov, Sergey; Perusek, Gail P.

2004-01-01

The high-cycle fatigue of composite stator vanes provided an accelerated life-state prior to insertion in a test stand engine. The accelerated testing was performed in the Structural Dynamics Laboratory at the NASA Glenn Research Center under the guidance of Structural Mechanics and Dynamics Branch personnel. Previous research on fixturing and test procedures developed at Glenn determined that engine vibratory conditions could be simulated for polymer matrix composite vanes by using the excitation of a combined slip table and electrodynamic shaker in Glenn's Structural Dynamics Laboratory. Bench-top testing gave researchers the confidence to test the coated vanes in a full-scale engine test.

Preliminary study, analysis and design for a power switch for digital engine actuators

NASA Technical Reports Server (NTRS)

Beattie, E. C.; Zickwolf, H. C., Jr.

1979-01-01

Innovative control configurations using high temperature switches to operate actuator driving solenoids were studied. The impact on engine control system life cycle costs and reliability of electronic control and (ECU) heat dissipation due to power conditioning and interface drivers were addressed. Various power supply and actuation schemes were investigated, including optical signal transmission and electronics on the actuator, engine driven alternator, and inside the ECU. The use of a switching shunt power conditioner results in the most significant decrease in heat dissipation within the ECU. No overall control system reliability improvement is projected by the use of remote high temperature switches for solenoid drivers.

Thermal barrier coating life prediction model development

NASA Technical Reports Server (NTRS)

Sheffler, K. D.; Demasi, J. T.

1985-01-01

A methodology was established to predict thermal barrier coating life in an environment simulative of that experienced by gas turbine airfoils. Specifically, work is being conducted to determine failure modes of thermal barrier coatings in the aircraft engine environment. Analytical studies coupled with appropriate physical and mechanical property determinations are being employed to derive coating life prediction model(s) on the important failure mode(s). An initial review of experimental and flight service components indicates that the predominant mode of TBC failure involves thermomechanical spallation of the ceramic coating layer. This ceramic spallation involves the formation of a dominant crack in the ceramic coating parallel to and closely adjacent to the metal-ceramic interface. Initial results from a laboratory test program designed to study the influence of various driving forces such as temperature, thermal cycle frequency, environment, and coating thickness, on ceramic coating spalling life suggest that bond coat oxidation damage at the metal-ceramic interface contributes significantly to thermomechanical cracking in the ceramic layer. Low cycle rate furnace testing in air and in argon clearly shows a dramatic increase of spalling life in the non-oxidizing environments.

Life cycle costing of food waste: A review of methodological approaches.

PubMed

De Menna, Fabio; Dietershagen, Jana; Loubiere, Marion; Vittuari, Matteo

2018-03-01

Food waste (FW) is a global problem that is receiving increasing attention due to its environmental and economic impacts. Appropriate FW prevention, valorization, and management routes could mitigate or avoid these effects. Life cycle thinking and approaches, such as life cycle costing (LCC), may represent suitable tools to assess the sustainability of these routes. This study analyzes different LCC methodological aspects and approaches to evaluate FW management and valorization routes. A systematic literature review was carried out with a focus on different LCC approaches, their application to food, FW, and waste systems, as well as on specific methodological aspects. The review consisted of three phases: a collection phase, an iterative phase with experts' consultation, and a final literature classification. Journal papers and reports were retrieved from selected databases and search engines. The standardization of LCC methodologies is still in its infancy due to a lack of consensus over definitions and approaches. Research on the life cycle cost of FW is limited and generally focused on FW management, rather than prevention or valorization of specific flows. FW prevention, valorization, and management require a consistent integration of LCC and Life Cycle Assessment (LCA) to avoid tradeoffs between environmental and economic impacts. This entails a proper investigation of methodological differences between attributional and consequential modelling in LCC, especially with regard to functional unit, system boundaries, multi-functionality, included cost, and assessed impacts. Further efforts could also aim at finding the most effective and transparent categorization of costs, in particular when dealing with multiple stakeholders sustaining costs of FW. Interpretation of results from LCC of FW should take into account the effect on larger economic systems. Additional key performance indicators and analytical tools could be included in consequential approaches. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Rocket University at KSC

NASA Technical Reports Server (NTRS)

Sullivan, Steven J.

2014-01-01

"Rocket University" is an exciting new initiative at Kennedy Space Center led by NASA's Engineering and Technology Directorate. This hands-on experience has been established to develop, refine & maintain targeted flight engineering skills to enable the Agency and KSC strategic goals. Through "RocketU", KSC is developing a nimble, rapid flight engineering life cycle systems knowledge base. Ongoing activities in RocketU develop and test new technologies and potential customer systems through small scale vehicles, build and maintain flight experience through balloon and small-scale rocket missions, and enable a revolving fresh perspective of engineers with hands on expertise back into the large scale NASA programs, providing a more experienced multi-disciplined set of systems engineers. This overview will define the Program, highlight aspects of the training curriculum, and identify recent accomplishments and activities.

SPIKE-2: a Practical Stirling Engine for Kilowatt Level Solar Power

NASA Technical Reports Server (NTRS)

Beale, W. T.

1984-01-01

Recent advances in the art of free piston Stirling engine design make possible the production of 1-10kW free piston Stirling linear alternator engine, hermetically sealed, efficient, durable and simple in construction and operation. Power output is in the form of single or three phase 60 Hz. AC, or DC. The three phase capability is available from single machines without need of external conditioning. Engine voltage control regains set voltage within 5 cycles in response to any load change. The existing SPIKE-2 design has an engine alternator efficiency of 25% at 650 C heater wall temperature and a service life of over three years in solar service. The same system can be scaled over a range of at least 100 watts to 25kW.

Engine throat/nozzle optics for plume spectroscopy

NASA Technical Reports Server (NTRS)

Bickford, R. L.; Duncan, D. B.

1991-01-01

The Task 2.0 Engine Throat/Nozzle Optics for Plume Spectroscopy, effort was performed under the NASA LeRC Development of Life Prediction Capabilities for Liquid Propellant Rocket Engines program. This Task produced the engineering design of an optical probe to enable spectroscopic measurements within the SSME main chamber. The probe mounts on the SSME nozzle aft manifold and collects light emitted from the throat plane and chamber. Light collected by the probe is transferred to a spectrometer through a fiber optic cable. The design analyses indicate that the probe will function throughout the engine operating cycle and is suitable for both test stand and flight operations. By detecting metallic emissions that are indicative of component degradation or incipient failure, engine shutdown can be initiated before catastrophic failure. This capability will protect valuable test stand hardware and provide enhanced mission safety.

Tank waste remediation system systems engineering management plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peck, L.G.

1998-01-08

This Systems Engineering Management Plan (SEMP) describes the Tank Waste Remediation System (TWRS) implementation of the US Department of Energy (DOE) systems engineering policy provided in 97-IMSD-193. The SEMP defines the products, process, organization, and procedures used by the TWRS Project to implement the policy. The SEMP will be used as the basis for tailoring the systems engineering applications to the development of the physical systems and processes necessary to achieve the desired end states of the program. It is a living document that will be revised as necessary to reflect changes in systems engineering guidance as the program evolves.more » The US Department of Energy-Headquarters has issued program management guidance, DOE Order 430. 1, Life Cycle Asset Management, and associated Good Practice Guides that include substantial systems engineering guidance.« less

Analysis of a topping-cycle, aircraft, gas-turbine-engine system which uses cryogenic fuel

NASA Technical Reports Server (NTRS)

Turney, G. E.; Fishbach, L. H.

1984-01-01

A topping-cycle aircraft engine system which uses a cryogenic fuel was investigated. This system consists of a main turboshaft engine that is mechanically coupled (by cross-shafting) to a topping loop, which augments the shaft power output of the system. The thermodynamic performance of the topping-cycle engine was analyzed and compared with that of a reference (conventional) turboshaft engine. For the cycle operating conditions selected, the performance of the topping-cycle engine in terms of brake specific fuel consumption (bsfc) was determined to be about 12 percent better than that of the reference turboshaft engine. Engine weights were estimated for both the topping-cycle engine and the reference turboshaft engine. These estimates were based on a common shaft power output for each engine. Results indicate that the weight of the topping-cycle engine is comparable with that of the reference turboshaft engine.

Study of LH2-fueled topping cycle engine for aircraft propulsion

NASA Technical Reports Server (NTRS)

Turney, G. E.; Fishbach, L. H.

1983-01-01

An analytical investigation was made of a topping cycle aircraft engine system which uses a cryogenic fuel. This system consists of a main turboshaft engine which is mechanically coupled (by cross-shafting) to a topping loop which augments the shaft power output of the system. The thermodynamic performance of the topping cycle engine was analyzed and compared with that of a reference (conventional-type) turboshaft engine. For the cycle operating conditions selected, the performance of the topping cycle engine in terms of brake specific fuel consumption (bsfc) was determined to be about 12 percent better than that of the reference turboshaft engine. Engine weights were estimated for both the topping cycle engine and the reference turboshaft engine. These estimates were based on a common shaft power output for each engine. Results indicate that the weight of the topping cycle engine is comparable to that of the reference turboshaft engine.

An overview of the Small Engine Component Technology (SECT) studies

NASA Technical Reports Server (NTRS)

Vanco, M. R.; Wintucky, W. T.; Niedzwiecki, R. W.

1986-01-01

The objectives of the joint NASA/Army SECT Studies were to identify high payoff technologies for year 2000 small gas turbine engine applications and to provide a technology plan for guiding future research and technology efforts applicable to rotorcraft, commuter and general aviation aircraft and cruise missiles. Competitive contracts were awarded to Allison, AVCO Lycoming, Garrett, Teledyne CAE and Williams International. This paper presents an overview of the contractors' study efforts for the commuter, rotorcraft, cruise missile, and auxiliary power (APU) applications with engines in the 250 to 1,000 horsepower size range. Reference aircraft, missions and engines were selected. Advanced engine configurations and cycles with projected year 2000 component technologies were evaluated and compared with a reference engine selected by the contractor. For typical commuter and rotorcraft applications, fuel savings of 22 percent to 42 percent can be attained. For $1/gallon and $2/gallon fuel, reductions in direct operating cost range from 6 percent to 16 percent and from 11 percent to 17 percent respectively. For subsonic strategic cruise missile applications, fuel savings of 38 percent to 54 percent can be achieved which allows 35 percent to 60 percent increase in mission range and life cycle cost reductions of 40 percent to 56 percent. High payoff technologies have been identified for all applications.

Dual Expander Cycle Rocket Engine with an Intermediate, Closed-cycle Heat Exchanger

NASA Technical Reports Server (NTRS)

Greene, William D. (Inventor)

2008-01-01

A dual expander cycle (DEC) rocket engine with an intermediate closed-cycle heat exchanger is provided. A conventional DEC rocket engine has a closed-cycle heat exchanger thermally coupled thereto. The heat exchanger utilizes heat extracted from the engine's fuel circuit to drive the engine's oxidizer turbomachinery.

Coping with Variability in Model-Based Systems Engineering: An Experience in Green Energy

NASA Astrophysics Data System (ADS)

Trujillo, Salvador; Garate, Jose Miguel; Lopez-Herrejon, Roberto Erick; Mendialdua, Xabier; Rosado, Albert; Egyed, Alexander; Krueger, Charles W.; de Sosa, Josune

Model-Based Systems Engineering (MBSE) is an emerging engineering discipline whose driving motivation is to provide support throughout the entire system life cycle. MBSE not only addresses the engineering of software systems but also their interplay with physical systems. Quite frequently, successful systems need to be customized to cater for the concrete and specific needs of customers, end-users, and other stakeholders. To effectively meet this demand, it is vital to have in place mechanisms to cope with the variability, the capacity to change, that such customization requires. In this paper we describe our experience in modeling variability using SysML, a leading MBSE language, for developing a product line of wind turbine systems used for the generation of electricity.

Systems Engineering Awareness

NASA Technical Reports Server (NTRS)

Lucero, John

2016-01-01

The presentation will provide an overview of the fundamentals and principles of Systems Engineering (SE). This includes understanding the processes that are used to assist the engineer in a successful design, build and implementation of solutions. The context of this presentation will be to describe the involvement of SE throughout the life-cycle of a project from cradle to grave. Due to the ever growing number of complex technical problems facing our world, a Systems Engineering approach is desirable for many reasons. The interdisciplinary technical structure of current systems, technical processes representing System Design, Technical Management and Product Realization are instrumental in the development and integration of new technologies into mainstream applications. This tutorial will demonstrate the application of SE tools to these types of problems..

40 CFR 90.410 - Engine test cycle.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine test cycle. 90.410 Section 90... Procedures § 90.410 Engine test cycle. (a) Follow the appropriate 6-mode test cycle for Class I, I-B and II engines and 2-mode test cycle for Class I-A, III, IV, and V engines when testing spark-ignition engines...

A conceptual model for megaprogramming

NASA Technical Reports Server (NTRS)

Tracz, Will

1990-01-01

Megaprogramming is component-based software engineering and life-cycle management. Magaprogramming and its relationship to other research initiatives (common prototyping system/common prototyping language, domain specific software architectures, and software understanding) are analyzed. The desirable attributes of megaprogramming software components are identified and a software development model and resulting prototype megaprogramming system (library interconnection language extended by annotated Ada) are described.

Improving The Prototyping Process In Department Of Defense Acquisition

DTIC Science & Technology

2014-06-01

System Flow Chart ................................................. 39 Figure 13. TRL Definitions (from ASD [R&E] 2011... ASD (R&E) Assistant Secretary of Defense for Research and Engineering BCL Business Capability Life cycle CDD Capability Development Document CDR...TRL 6 cannot be attained until the technology has been demonstrated in a relevant operational environment ( ASD [R&E] 2011). A technology that has

Impact of the Acquisition Corps Membership Requirement 24 Business-Credit Hours on the Navy Acquisition Workforce

DTIC Science & Technology

2016-12-01

ROTC Reserve Officers’ Training Corps S&T Science and Technology S&TM Science and Technology Manager SDO Special Duty Officer SME Subject Matter...engineering, industrial property management, information technology , life cycle logistics, program management, production , quality and manufacturing...16  4.  Auditing ........................................................................................16  5.  Test and

MSFC Combustion Devices in 2001

NASA Technical Reports Server (NTRS)

Dexter, Carol; Turner, James (Technical Monitor)

2001-01-01

The objectives of the project detailed in this viewgraph presentation were to reduce thrust assembly weights to create lighter engines and to increase the cycle life and/or operating temperatures. Information is given on material options (metal matrix composites and polymer matrix composites), ceramic matrix composites subscale liners, lightweight linear chambers, lightweight injector development, liquid/liquid preburner tasks, and vortex chamber tasks.

An application generator for rapid prototyping of Ada real-time control software

NASA Technical Reports Server (NTRS)

Johnson, Jim; Biglari, Haik; Lehman, Larry

1990-01-01

The need to increase engineering productivity and decrease software life cycle costs in real-time system development establishes a motivation for a method of rapid prototyping. The design by iterative rapid prototyping technique is described. A tool which facilitates such a design methodology for the generation of embedded control software is described.

CMMI(Registered) for Development, Version 1.3

DTIC Science & Technology

2010-11-01

ISO /IEC 15288:2008 Systems and Software Engineering – System Life Cycle Processes [ ISO 2008b] ISO /IEC 27001 :2005 Information technology – Security...IEC 2005 International Organization for Standardization and International Electrotechnical Commission. ISO /IEC 27001 Information Technology...International Electrotechnical Commission ( ISO /IEC) body of standards. CMMs focus on improving processes in an organization. They contain the

CMMI(Registered) for Acquisition, Version 1.3. CMMI-ACQ, V1.3

DTIC Science & Technology

2010-11-01

and Software Engineering – System Life Cycle Processes [ ISO 2008b] ISO /IEC 27001 :2005 Information technology – Security techniques – Information...International Organization for Standardization and International Electrotechnical Commission. ISO /IEC 27001 Information Technology – Security Techniques...International Organization for Standardization/International Electrotechnical Commission ( ISO /IEC) body of standards. CMMs focus on improving processes

LCD OF AIR INTAKE MANIFOLDS PHASE 2: FORD F250 AIR INTAKE MANIFOLD

EPA Science Inventory

The life cycle design methodology was applied to the design analysis of three alternatives for the lower plehum of the air intake manifold for us with a 5.4L F-250 truck engine: a sand cast aluminum, a lost core molded nylon composite, and a vibration welded nylon composite. The ...

To Stand the Test of Time: Long-Term Stewardship of Digital Data Sets in Science and Engineering. A Report to the National Science Foundation from the ARL Workshop on New Collaborative Relationships--The Role of Academic Libraries in the Digital Data Universe (Arlington, Virginia, September 26-27, 2006)

ERIC Educational Resources Information Center

Friedlander, Amy; Adler, Prudence

2006-01-01

The rapid adoption of information technology and ubiquitous networking has transformed the research and education landscape. Central to this transformation are scientific and engineering digital data collections. The life cycle management challenges associated with these intellectual assets are substantial. This is a report of a two-day workshop…

Security engineering: systems engineering of security through the adaptation and application of risk management

NASA Technical Reports Server (NTRS)

Gilliam, David P.; Feather, Martin S.

2004-01-01

Information Technology (IT) Security Risk Management is a critical task in the organization, which must protect its resources and data against the loss of confidentiality, integrity, and availability. As systems become more complex and diverse, and more vulnerabilities are discovered while attacks from intrusions and malicious content increase, it is becoming increasingly difficult to manage IT security. This paper describes an approach to address IT security risk through risk management and mitigation in both the institution and in the project life cycle.

Mariner Jupiter/Saturn LCSSE thruster/valve assembly and injection propulsion unit rocket engine assemblies: 0.2-lbf T/VA development and margin limit test report

NASA Technical Reports Server (NTRS)

Clark, E. C.

1975-01-01

Thruster valve assemblies (T/VA's) were subjected to the development test program for the combined JPL Low-Cost Standardized Spacecraft Equipment (LCSSE) and Mariner Jupiter/Saturn '77 spacecraft (MJS) programs. The development test program was designed to achieve the following program goals: (1) demonstrate T/VA design compliance with JPL Specifications, (2) to conduct a complete performance Cf map of the T/VA over the full operating range of environment, (3) demonstrate T/VA life capability and characteristics of life margin for steady-state limit cycle and momentum wheel desaturation duty cycles, (4) verification of structural design capability, and (5) generate a computerized performance model capable of predicting T/VA operation over pressures ranging from 420 to 70 psia, propellant temperatures ranging from 140 F to 40 F, pulse widths of 0.008 to steady-state operation with unlimited duty cycle capability, and finally predict the transient performance associated with reactor heatup during any given duty cycle, start temperature, feed pressure, and propellant temperature conditions.

Development of ambient temperature secondary lithium cells

NASA Technical Reports Server (NTRS)

Subbarao, S.; Shen, D. H.; Dawson, S.; Deligiannis, F.; Taraszkiewicz, J.; Halpert, G.

1988-01-01

JPL is developing ambient temperature secondary lithium cells for future spacecraft applications. Prior studies on experimental laboratory type Li-TiS2 cells yielded promising results in terms of cycle life and rate capability. To further assess the performance of this cell, 5 Ah engineering model cells were developed. Initially baseline cells were designed and fabricated. Each cell had 15 cathodes and 16 anodes and the ratio of anode to cathode capacity is 6:1. A solution of 1.5 molar LiAsF6 in 2Me-THF was used as the electrolyte. Cells were evaluated for their cycle life at C/1 and C/5 discharge rates and 100 percent depth of discharge. The cells were cycled between voltage limits 1.7 and 2.8 volts. The rate of charge in all cases is C/10. The results obtained indicate that cells can operate at C/10 to C/2 discharge rates and have an initial energy density of 70 Wh/kg. Cells delivered more than 100 cycles at C/2 discharge rate. The details of cell design, the test program, and the results obtained are described.

Development of ambient temperature secondary lithium cells

NASA Technical Reports Server (NTRS)

Subbarao, S.; Shen, D. H.; Dawson, S.; Deligiannis, F.; Taraszkiewicz, J.; Halpert, Gerald

1987-01-01

JPL is developing ambient temperature secondary lithium cells for future spacecraft applications. Prior studies on experimental laboratory type Li-TiS2 cells yielded promising results in terms of cycle life and rate capability. To further assess the performance of this cell, 5 Ah engineering model cells were developed. Initially baseline cells were designed and fabricated. Each cell had 15 cathodes and 16 anodes and the ratio of anode to cathode capacity is 6:1. A solution of 1.5 molar LiAsF6 in 2Me-THF was used as the electrolyte. Cells were evaluated for their cycle life at C/1 and C/5 discharge rates and 100 percent depth of discharge. The cells were cycled between voltage limits 1.7 and 2.8 volts. The rate of charge in all cases is C/10. The results obtained indicate that cells can operate at C/10 to C/2 discharge rates and have an initial energy density of 70 Wh/kg. Cells delivered more than 100 cycles at C/2 discharge rate. The details of cell design, the test program, and the results obtained are described.

Cell voltage versus electrode potential range in aqueous supercapacitors

PubMed Central

Dai, Zengxin; Peng, Chuang; Chae, Jung Hoon; Ng, Kok Chiang; Chen, George Z.

2015-01-01

Supercapacitors with aqueous electrolytes and nanostructured composite electrodes are attractive because of their high charging-discharging speed, long cycle life, low environmental impact and wide commercial affordability. However, the energy capacity of aqueous supercapacitors is limited by the electrochemical window of water. In this paper, a recently reported engineering strategy is further developed and demonstrated to correlate the maximum charging voltage of a supercapacitor with the capacitive potential ranges and the capacitance ratio of the two electrodes. Beyond the maximum charging voltage, a supercapacitor may still operate, but at the expense of a reduced cycle life. In addition, it is shown that the supercapacitor performance is strongly affected by the initial and zero charge potentials of the electrodes. Further, the differences are highlighted and elaborated between freshly prepared, aged under open circuit conditions, and cycled electrodes of composites of conducting polymers and carbon nanotubes. The first voltammetric charging-discharging cycle has an electrode conditioning effect to change the electrodes from their initial potentials to the potential of zero voltage, and reduce the irreversibility. PMID:25897670

Prolonging thermal barrier coated specimen life by thermal cycle management

NASA Technical Reports Server (NTRS)

Hendricks, R. C.; Mcdonald, G.; Poolos, N. P.

1981-01-01

Thermal barrier coatings applied to the heated side of engine components such as seals, combustor, and blades of a gas turbine offer a potential increase in efficiency through the use of higher gas temperatures or less cooling air or benefits arising from extended component life by reducing component metal temperatures. The considered investigation has the objective to show that while a thermal barrier coated (TBC) specimen can be brought to a fixed temperature using various fuel-air ratio (F/A) values, lower calculated stresses are associated with lower (F/A) values. This implies that control of (F/A) values (i.e., rates of heat input) during the starting transient and to a lesser extent during shutdown and operation, offers a potential method of improving TBC lifetime through thermal cycle management.

POLARIS: Helping Managers Get Answers Fast!

NASA Technical Reports Server (NTRS)

Corcoran, Patricia M.; Webster, Jeffery

2007-01-01

This viewgraph presentation reviews the Project Online Library and Resource Information System (POLARIS) system. It is NASA-wide, web-based system, providing access to information related to Program and Project Management. It will provide a one-stop shop for access to: a searchable, sortable database of all requirements for all product lines, project life cycle diagrams with reviews, project life cycle diagrams with reviews, project review definitions with products review information from NPR 7123.1, NASA Systems Engineering Processes and Requirements, templates and examples of products, project standard WBSs with dictionaries, and requirements for implementation and approval, information from NASA s Metadata Manager (MdM): Attributes of Missions, Themes, Programs & Projects, NPR7120.5 waiver form and instructions and much more. The presentation reviews the plans and timelines for future revisions and modifications.

Predictive modeling and reducing cyclic variability in autoignition engines

DOEpatents

Hellstrom, Erik; Stefanopoulou, Anna; Jiang, Li; Larimore, Jacob

2016-08-30

Methods and systems are provided for controlling a vehicle engine to reduce cycle-to-cycle combustion variation. A predictive model is applied to predict cycle-to-cycle combustion behavior of an engine based on observed engine performance variables. Conditions are identified, based on the predicted cycle-to-cycle combustion behavior, that indicate high cycle-to-cycle combustion variation. Corrective measures are then applied to prevent the predicted high cycle-to-cycle combustion variation.

7 CFR 2902.25 - 2-Cycle engine oils.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false 2-Cycle engine oils. 2902.25 Section 2902.25... Items § 2902.25 2-Cycle engine oils. (a) Definition. Lubricants designed for use in 2-cycle engines to... procurement preference for qualifying biobased 2-cycle engine oils. By that date, Federal agencies that have...

Main Chamber Injectors for Advanced Hydrocarbon Booster Engines

NASA Technical Reports Server (NTRS)

Long, Matthew R.; Bazarov, Vladimir G.; Anderson, William E.

2003-01-01

Achieving the highest possible specific impulse has long been a key driver for space launch systems. Recently, more importance has been placed on the need for increased reliability and streamlined launch operations. These general factors along with more specific mission requirements have provided a new focus that is centered on the oxidizer rich staged combustion (ORSC) cycle. Despite a history of use in Russia that extends back to the 1960's, a proven design methodology for ORSC cycle engines does not exist in the West. This lack of design expertise extends to the main chamber injector, a critical subcomponent that largely determines the engine performance and main chamber life. The goals of the effort described here are to establish an empirical knowledge base to provide a fundamental understanding of main chamber injectors and for verification of an injector design methodology for the ORSC cycle. The design of a baseline injector element, derived from information on Russian engines in the open literature, is presented. The baseline injector comprises a gaseous oxidizer core flow and an annular swirling fuel flow. Sets of equations describing the steady-state and the dynamic characteristics of the injector are presented; these equations, which form the basis of the design analysis methodology, will be verified in tests later this year. On-going cold flow studies, using nitrogen and water as simulants, are described which indicate highly atomized and symmetric sprays.

An analysis of innovation in materials and energy

NASA Astrophysics Data System (ADS)

Connelly, Michael

This dissertation presents an analysis of innovation in engineering materials and energy sources. More than fifty engineering materials and fourteen energy sources were selected for an evaluation of the relationship between the yearly production activity and yearly patent counts, which may be considered as a measure of innovation, for each. Through the employment of correlation theory, best-fit and origin shift analyses, it has been determined here that engineering materials and energy sources display similar life cycle and innovative activity behaviors. Correlation theory revealed a relationship between the yearly production and yearly patent counts indicating the extent that production and innovation affect each other. Best-fit analysis determined that four-stage life cycles exist for both engineering materials (metals and non-metals) and energy sources. Correlation and best-fit indicators of an estimated Stage III are confirmed by the presence of an origin shift of the patent data when compared to the production data which indicates that patents, or innovation, are driving, or being driven by, production. This driving force could represent the constructive or destructive side of the innovative process, with such sides being delineated by a possible universal constant above which there is destructive innovative behavior and below which exists constructive innovation. The driving force may also illustrate the manner in which an engineering material or energy source transitions into an innovatively less active state, enter Stage IV and possibly become a commodity. A possible Stage V, indicating "Final Death", is introduced in which production is on a steep decline with no signs of recovery. Additionally, innovatively active energy sources are often found to utilize or be supported by innovatively active engineering materials. A model is presented that can be used for the evaluation of innovation and production that can be applied to both engineering materials and energy sources that may be used to predict the innovative behavior of these resources in order that they can be more effectively allocated and utilized.

CanSat Competition: Contributing to the Development of NASA's Vision for Robotic Space Exploration

NASA Technical Reports Server (NTRS)

Berman, Joshua; Berman, Timothy; Billheimer, Thomas; Biclmer. Elizabeth; Hood, Stuart; Neas, Charles

2007-01-01

CanSat is an international student design-build-launch competition organized by the American Astronautical Society (AAS) and American Institute of Aeronautics and Astronautics (AIAA). The competition is also sponsored by the Naval Research Laboratory (NRL) and the National Aeronautics and Space Administration (NASA). The CanSat competition is designed for college, university and high school students wanting to participate in an applicable space-related competition. The objective of the CanSat competition is to complete space exploration missions by designing a specific system for a small sounding rocket payload which will follow and perform to a specific set of rules and guidelines for each year's competition. The competition encompasses a complete life-cycle of one year which includes all phases of design, integration, testing, judging and competition. The mission guidelines are based from space exploration missions and include bonus requirement options which teams may choose to participate in. The fundamental goal of the competition is to educate future engineers and scientists. This is accomplished by students applying systems engineering practices to a development project that incorporates an end-to-end life cycle, from requirements analysis, through preliminary design, integration and testing, an actual flight of the CanSat, and concluding with a post-mission debrief. This is done specifically with space related missions to bring a unique aspect of engineering and design to the competition. The competition has been progressing since its creation in 2005. The competition was originally meant to purely convey the engineering and design process to its participants, but through many experiences the competition has also undergone a learning experience with respect to systems engineering process and design. According

Lead-acid batteries for micro- and mild-hybrid applications

NASA Astrophysics Data System (ADS)

Valenciano, J.; Fernández, M.; Trinidad, F.; Sanz, L.

Car manufactures have announced the launch in coming months of vehicles with reduced emissions due to the introduction of new functions like stop-start and regenerative braking. Initial performance request of automotive lead-acid batteries are becoming more and more demanding and, in addition to this, cycle life with new accelerated ageing profiles are being proposed in order to determine the influence of the new functions on the expected battery life. This paper will show how different lead-acid battery technologies comply with these new demands, from an improved version of the conventional flooded SLI battery to the high performance of spiral wound valve-regulated lead-acid (VRLA) battery. Different approaches have been studied for improving conventional flooded batteries, i.e., either by the addition of new additives for reducing electrolyte stratification or by optimisation of the battery design to extend cycling life in partial state of charge conditions. With respect to VRLA technology, two different battery designs have been compared. Spiral wound design combines excellent power capability and cycle life under different depth of discharge (DoD) cycling conditions, but flat plate design outperform the latter in energy density due to better utilization of the space available in a prismatic enclosure. This latter design is more adequate for high end class vehicles with high electrical energy demand, whereas spiral wound is better suited for high power/long life demand of commercial vehicle. High temperature behaviour (75 °C) is rather poor for both designs due to water loss, and then VRLA batteries should preferably be located out of the engine compartment.

Artificial intelligence approaches to software engineering

NASA Technical Reports Server (NTRS)

Johannes, James D.; Macdonald, James R.

1988-01-01

Artificial intelligence approaches to software engineering are examined. The software development life cycle is a sequence of not so well-defined phases. Improved techniques for developing systems have been formulated over the past 15 years, but pressure continues to attempt to reduce current costs. Software development technology seems to be standing still. The primary objective of the knowledge-based approach to software development presented in this paper is to avoid problem areas that lead to schedule slippages, cost overruns, or software products that fall short of their desired goals. Identifying and resolving software problems early, often in the phase in which they first occur, has been shown to contribute significantly to reducing risks in software development. Software development is not a mechanical process but a basic human activity. It requires clear thinking, work, and rework to be successful. The artificial intelligence approaches to software engineering presented support the software development life cycle through the use of software development techniques and methodologies in terms of changing current practices and methods. These should be replaced by better techniques that that improve the process of of software development and the quality of the resulting products. The software development process can be structured into well-defined steps, of which the interfaces are standardized, supported and checked by automated procedures that provide error detection, production of the documentation and ultimately support the actual design of complex programs.

Study of a LH2-fueled topping cycle engine for aircraft propulsion

NASA Technical Reports Server (NTRS)

Turney, G. E.; Fishbach, L. H.

1983-01-01

An analytical investigation was made of a topping cycle aircraft engine system which uses a cryogenic fuel. This system consists of a main turboshaft engine which is mechanically coupled (by cross-shafting) to a topping loop which augments the shaft power output of the system. The thermodynamic performance of the topping cycle engine was analyzed and compared with that of a reference (conventional-type) turboshaft engine. For the cycle operating conditions selected, the performance of the topping cycle engine in terms of brake specific fuel consumption (bsfc) was determined to be about 12 percent better than that of the reference turboshaft engine. Engine weights were estimated for both the topping cycle engine and the reference turboshaft engine. These estimates were based on a common shaft power output for each engine. Results indicate that the weight of the topping cycle engine is comparable to that of the reference turboshaft engine. Previously announced in STAR as N83-34942

Cyclic structural analyses of anisotropic turbine blades for reusable space propulsion systems. [ssme fuel turbopump

NASA Technical Reports Server (NTRS)

Manderscheid, J. M.; Kaufman, A.

1985-01-01

Turbine blades for reusable space propulsion systems are subject to severe thermomechanical loading cycles that result in large inelastic strains and very short lives. These components require the use of anisotropic high-temperature alloys to meet the safety and durability requirements of such systems. To assess the effects on blade life of material anisotropy, cyclic structural analyses are being performed for the first stage high-pressure fuel turbopump blade of the space shuttle main engine. The blade alloy is directionally solidified MAR-M 246 alloy. The analyses are based on a typical test stand engine cycle. Stress-strain histories at the airfoil critical location are computed using the MARC nonlinear finite-element computer code. The MARC solutions are compared to cyclic response predictions from a simplified structural analysis procedure developed at the NASA Lewis Research Center.

Environmental Life Cycle Assessment Model for Soil Bioengineering Measures on Infrastructure Slopes

NASA Astrophysics Data System (ADS)

Hoerbinger, Stephan; Obriejetan, Michael

2015-04-01

Soil bioengineering techniques can be a helpful instrument for civil engineers taking into account not only technical but also ecological, socio-economic and sustainability aspects. Environmental Life Cycle Assessment (LCA) models can serve as supplementary evaluation methods to economic analyses, taking into account the resource demand and environmental burdens of engineering structures. The presented LCA model includes the functional grade of structures in addition to environmental aspects. When using vegetation as living construction material, several factors have to be considered. There is the provision of ecosystem services of plants, such as the stabilization of the slope through its root-system, CO2 sequestration through biomass production et cetera. However, it must be noted that vegetation can cause security issues on infrastructure facilities and entail costs through the necessity of maintenance works. For this reason, it is necessary to already define the target systems during the planning phase of a soil bioengineering structure. In this way, necessary measures can be adapted in all life cycles of a structure. The objective of the presented LCA model is to serve as a basis for the definition of target systems. In the designed LCA model the soil bioengineering structures are divided into four life phases; construction phase, operational phase, end of life phase and subsequent use phase. A main objective of the LCA model is the understanding of the "Cumulative Energy Demand" (CED) and "Global Warming Potential" (GWP) of soil bioengineering structures during all life cycle phases. Additionally, the biomass production and the CO2 sequestration potential of the used plants are regarded as well as the functional integrity of the soil bioengineering system. In the life phase of soil bioengineering structures, a major part of the energy input is required during the construction phase. This is mainly due to the cumulative energy demand of the inert materials used. The principle of biological engineering constructions is based on the combination of dead and living materials and the emerging positive synergistic effects. The dead auxiliaries (stone, wood, etc.) protect the living plants until they undertake technical functions. During the operational phase of the structure, maintenance work has to be done in order to maintain the protective properties of the used plants. Through measures like cutting the vegetation back to the trunk, energy will be put into the system (e.g. through machine use), but will also be put out in form of biomass. Additionally, carbon is sequestered by the biomass production of the plants. The end of life phase is reached after the projected lifetime of a structure. Outside of zones with plant growth restrictions like within a clearance gauge, soil bioengineering approaches are designed to have a subsequent use phase. That means, that after the actual lifespan of the construction, a forest should have developed and maintain its balance by natural succession. The LCA model aims at supporting sustainable management strategies for CED and GWP as a base for Green Public Procurement and eco- friendly implementation and maintenance of soil bioengineering structures on infrastructure slopes.

High-temperature fatigue in metals - A brief review of life prediction methods developed at the Lewis Research Center of NASA

NASA Technical Reports Server (NTRS)

Halford, G. R.

1983-01-01

The presentation focuses primarily on the progress we at NASA Lewis Research Center have made. The understanding of the phenomenological processes of high temperature fatigue of metals for the purpose of calculating lives of turbine engine hot section components is discussed. Improved understanding resulted in the development of accurate and physically correct life prediction methods such as Strain-Range partitioning for calculating creep fatigue interactions and the Double Linear Damage Rule for predicting potentially severe interactions between high and low cycle fatigue. Examples of other life prediction methods are also discussed. Previously announced in STAR as A83-12159

A proposed Kalman filter algorithm for estimation of unmeasured output variables for an F100 turbofan engine

NASA Technical Reports Server (NTRS)

Alag, Gurbux S.; Gilyard, Glenn B.

1990-01-01

To develop advanced control systems for optimizing aircraft engine performance, unmeasurable output variables must be estimated. The estimation has to be done in an uncertain environment and be adaptable to varying degrees of modeling errors and other variations in engine behavior over its operational life cycle. This paper represented an approach to estimate unmeasured output variables by explicitly modeling the effects of off-nominal engine behavior as biases on the measurable output variables. A state variable model accommodating off-nominal behavior is developed for the engine, and Kalman filter concepts are used to estimate the required variables. Results are presented from nonlinear engine simulation studies as well as the application of the estimation algorithm on actual flight data. The formulation presented has a wide range of application since it is not restricted or tailored to the particular application described.

The Need for V&V in Reuse-Based Software Engineering

NASA Technical Reports Server (NTRS)

Addy, Edward A.

1997-01-01

V&V is currently performed during application development for many systems, especially safety-critical and mission-critical systems. The V&V process is intended to discover errors, especially errors related to entire' domain or product line rather than a critical processing, as early as possible during the development process. The system application provides the context under which the software artifacts are validated. engineering. This paper describes a framework that extends V&V from an individual application system to a product line of systems that are developed within an architecture-based software engineering environment. This framework includes the activities of traditional application-level V&V, and extends these activities into the transition between domain engineering and application engineering. The framework includes descriptions of the types of activities to be performed during each of the life-cycle phases, and provides motivation for activities.

Definition of propulsion system for V/STOL research and technology aircraft

NASA Technical Reports Server (NTRS)

1977-01-01

Wind tunnel test support, aircraft contractor support, a propulsion system computer card deck, preliminary design studies, and propulsion system development plan are reported. The Propulsion system consists of two lift/cruise turbofan engines, one turboshaft engine and one lift fan connected together with shafting into a combiner gearbox. Distortion parameter levels from 40 x 80 test data were within the established XT701-AD-700 limits. The three engine-three fan system card deck calculates either vertical or conventional flight performance, installed or uninstalled. Design study results for XT701 engine modifications, bevel gear cross shaft location, fixed and tilt fan frames and propulsion system controls are described. Optional water-alcohol injection increased total net thrust 10.3% on a 90 F day. Engines have sufficient turbine life for 500 hours of the RTA duty cycle.

Advanced engineering environment pilot project.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwegel, Jill; Pomplun, Alan R.; Abernathy, Rusty

2006-10-01

The Advanced Engineering Environment (AEE) is a concurrent engineering concept that enables real-time process tooling design and analysis, collaborative process flow development, automated document creation, and full process traceability throughout a product's life cycle. The AEE will enable NNSA's Design and Production Agencies to collaborate through a singular integrated process. Sandia National Laboratories and Parametric Technology Corporation (PTC) are working together on a prototype AEE pilot project to evaluate PTC's product collaboration tools relative to the needs of the NWC. The primary deliverable for the project is a set of validated criteria for defining a complete commercial off-the-shelf (COTS) solutionmore » to deploy the AEE across the NWC.« less

Biomass Conversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Decker, Steve; Brunecky, Roman; Lin, Chien-Yuan

2017-08-02

Biomass constitutes all the plant matter found on our planet, and is produced directly by photosynthesis, the fundamental engine of life on earth. It is the photosynthetic capability of plants to utilize carbon dioxide from the atmosphere that leads to its designation as a 'carbon neutral' fuel, meaning that it does not introduce new carbon into the atmosphere. This article discusses the life cycle assessments of biomass use and the magnitude of energy captured by photosynthesis in the form of biomass on the planet to appraise approaches to tap this energy to meet the ever-growing demand for energy.

Conventionally cast and forged copper alloy for high-heat-flux thrust chambers

NASA Technical Reports Server (NTRS)

Kazaroff, John M.; Repas, George A.

1987-01-01

The combustion chamber liner of the space shuttle main engine is made of NARloy-Z, a copper-silver-zirconium alloy. This alloy was produced by vacuum melting and vacuum centrifugal casting; a production method that is currently now available. Using conventional melting, casting, and forging methods, NASA has produced an alloy of the same composition called NASA-Z. This report compares the composition, microstructure, tensile properties, low-cycle fatigue life, and hot-firing life of these two materials. The results show that the materials have similar characteristics.

An Architecture, System Engineering, and Acquisition Approach for Space System Software Resiliency

NASA Astrophysics Data System (ADS)

Phillips, Dewanne Marie

Software intensive space systems can harbor defects and vulnerabilities that may enable external adversaries or malicious insiders to disrupt or disable system functions, risking mission compromise or loss. Mitigating this risk demands a sustained focus on the security and resiliency of the system architecture including software, hardware, and other components. Robust software engineering practices contribute to the foundation of a resilient system so that the system "can take a hit to a critical component and recover in a known, bounded, and generally acceptable period of time". Software resiliency must be a priority and addressed early in the life cycle development to contribute a secure and dependable space system. Those who develop, implement, and operate software intensive space systems must determine the factors and systems engineering practices to address when investing in software resiliency. This dissertation offers methodical approaches for improving space system resiliency through software architecture design, system engineering, increased software security, thereby reducing the risk of latent software defects and vulnerabilities. By providing greater attention to the early life cycle phases of development, we can alter the engineering process to help detect, eliminate, and avoid vulnerabilities before space systems are delivered. To achieve this objective, this dissertation will identify knowledge, techniques, and tools that engineers and managers can utilize to help them recognize how vulnerabilities are produced and discovered so that they can learn to circumvent them in future efforts. We conducted a systematic review of existing architectural practices, standards, security and coding practices, various threats, defects, and vulnerabilities that impact space systems from hundreds of relevant publications and interviews of subject matter experts. We expanded on the system-level body of knowledge for resiliency and identified a new software architecture framework and acquisition methodology to improve the resiliency of space systems from a software perspective with an emphasis on the early phases of the systems engineering life cycle. This methodology involves seven steps: 1) Define technical resiliency requirements, 1a) Identify standards/policy for software resiliency, 2) Develop a request for proposal (RFP)/statement of work (SOW) for resilient space systems software, 3) Define software resiliency goals for space systems, 4) Establish software resiliency quality attributes, 5) Perform architectural tradeoffs and identify risks, 6) Conduct architecture assessments as part of the procurement process, and 7) Ascertain space system software architecture resiliency metrics. Data illustrates that software vulnerabilities can lead to opportunities for malicious cyber activities, which could degrade the space mission capability for the user community. Reducing the number of vulnerabilities by improving architecture and software system engineering practices can contribute to making space systems more resilient. Since cyber-attacks are enabled by shortfalls in software, robust software engineering practices and an architectural design are foundational to resiliency, which is a quality that allows the system to "take a hit to a critical component and recover in a known, bounded, and generally acceptable period of time". To achieve software resiliency for space systems, acquirers and suppliers must identify relevant factors and systems engineering practices to apply across the lifecycle, in software requirements analysis, architecture development, design, implementation, verification and validation, and maintenance phases.

Fatigue life prediction of liquid rocket engine combustor with subscale test verification

NASA Astrophysics Data System (ADS)

Sung, In-Kyung

Reusable rocket systems such as the Space Shuttle introduced a new era in propulsion system design for economic feasibility. Practical reusable systems require an order of magnitude increase in life. To achieve this improved methods are needed to assess failure mechanisms and to predict life cycles of rocket combustor. A general goal of the research was to demonstrate the use of subscale rocket combustor prototype in a cost-effective test program. Life limiting factors and metal behaviors under repeated loads were surveyed and reviewed. The life prediction theories are presented, with an emphasis on studies that used subscale test hardware for model validation. From this review, low cycle fatigue (LCF) and creep-fatigue interaction (ratcheting) were identified as the main life limiting factors of the combustor. Several life prediction methods such as conventional and advanced viscoplastic models were used to predict life cycle due to low cycle thermal stress, transient effects, and creep rupture damage. Creep-fatigue interaction and cyclic hardening were also investigated. A prediction method based on 2D beam theory was modified using 3D plate deformation theory to provide an extended prediction method. For experimental validation two small scale annular plug nozzle thrusters were designed, built and tested. The test article was composed of a water-cooled liner, plug annular nozzle and 200 psia precombustor that used decomposed hydrogen peroxide as the oxidizer and JP-8 as the fuel. The first combustor was tested cyclically at the Advanced Propellants and Combustion Laboratory at Purdue University. Testing was stopped after 140 cycles due to an unpredicted failure mechanism due to an increasing hot spot in the location where failure was predicted. A second combustor was designed to avoid the previous failure, however, it was over pressurized and deformed beyond repair during cold-flow test. The test results are discussed and compared to the analytical and numerical predictions. A detailed comparison was not performed, however, due to the lack of test data resulting from a failure of the test article. Some theoretical and experimental aspects such as fin effect and round corner were found to reduce the discrepancy between prediction and test results.

System-of-Systems Technology-Portfolio-Analysis Tool

NASA Technical Reports Server (NTRS)

O'Neil, Daniel; Mankins, John; Feingold, Harvey; Johnson, Wayne

2012-01-01

Advanced Technology Life-cycle Analysis System (ATLAS) is a system-of-systems technology-portfolio-analysis software tool. ATLAS affords capabilities to (1) compare estimates of the mass and cost of an engineering system based on competing technological concepts; (2) estimate life-cycle costs of an outer-space-exploration architecture for a specified technology portfolio; (3) collect data on state-of-the-art and forecasted technology performance, and on operations and programs; and (4) calculate an index of the relative programmatic value of a technology portfolio. ATLAS facilitates analysis by providing a library of analytical spreadsheet models for a variety of systems. A single analyst can assemble a representation of a system of systems from the models and build a technology portfolio. Each system model estimates mass, and life-cycle costs are estimated by a common set of cost models. Other components of ATLAS include graphical-user-interface (GUI) software, algorithms for calculating the aforementioned index, a technology database, a report generator, and a form generator for creating the GUI for the system models. At the time of this reporting, ATLAS is a prototype, embodied in Microsoft Excel and several thousand lines of Visual Basic for Applications that run on both Windows and Macintosh computers.

Gasoline-powered series hybrid cars cause lower life cycle carbon emissions than battery cars

NASA Astrophysics Data System (ADS)

Meinrenken, Christoph; Lackner, Klaus S.

2012-02-01

Battery cars powered by grid electricity promise reduced life cycle green house gas (GHG) emissions from the automotive sector. Such scenarios usually point to the much higher emissions from conventional, internal combustion engine cars. However, today's commercially available series hybrid technology achieves the well known efficiency gains in electric drivetrains (regenerative breaking, lack of gearbox) even if the electricity is generated onboard, from conventional fuels. Here, we analyze life cycle GHG emissions for commercially available, state-of the-art plug-in battery cars (e.g. Nissan Leaf) and those of commercially available series hybrid cars (e.g., GM Volt, at same size and performance). Crucially, we find that series hybrid cars driven on (fossil) gasoline cause fewer emissions (126g CO2eq per km) than battery cars driven on current US grid electricity (142g CO2eq per km). We attribute this novel finding to the significant incremental emissions from plug-in battery cars due to losses during grid transmission and battery dis-/charging, and manufacturing larger batteries. We discuss crucial implications for strategic policy decisions towards a low carbon automotive sector as well as relative land intensity when powering cars by biofuel vs. bioelectricity.

Life cycle analysis of mitigation methodologies for railway rolling noise and groundbourne vibration.

PubMed

Tuler, Mariana Valente; Kaewunruen, Sakdirat

2017-04-15

Negative outcomes such as noise and vibration generated by railways have become a challenge for both industry and academia in order to guarantee that the railway system can accomplish its purposes and at the same time provide comfort for users and people living in the neighbourhood along the railway corridor. The research interest on this field has been increasing and the advancement in noise and vibration mitigation methodologies can be observed using various engineering techniques that are constantly put into test to solve such effects. In contrast, the life cycle analysis of the mitigation measures has not been thoroughly carried out. There is also a lack of detailed evaluation in the efficiency of various mechanisms for controlling rolling noise and ground-borne vibration. This research is thus focussed on the evaluation of materials used, the total cost associated with the maintenance of such the measures and the carbon footprint left for each type of mechanism. The insight into carbon footprint together with life cycle cost will benefit decision making process for the industry in the selection of optimal and suitable mechanism since the environmental impact is a growing concern around the world. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of ceramics for stator applications: Gas turbine engines interim report. Stator fabrication and evaluation

NASA Technical Reports Server (NTRS)

Arnon, N.; Trela, W.

1983-01-01

The objective was to assess current ceramic materials, fabrication processes, reliability prediction, and stator durability when subjected to simulated automotive gas turbine engine operating conditions. Ceramic one-piece stators were fabricated of two materials, silicon nitride and silicon carbide, using two near-net-shape processes, slip casting and injection molding. Non-destructive evaluation tests were conducted on all stators identifying irregularities which could contribute to failures under durability testing. Development of the test rig and automatic control system for repeatably controlling air flow rate and temperature over a highly transient durability duty cycle is discussed. Durability results are presented for repeated thermal cycle testing of the ceramic one-piece stators. Two duty cycles were used, encompassing the temperature ranges of 704 to 1204 C (1300 to 2200 F) and 871 to 1371 C (1600 to 2500 F). Tests were conducted on 28 stators, accumulating 135,551 cycles in 2441 hours of hot testing. Cyclic durability for the ceramic one-piece stator was demonstrated to be in excess of 500 hours, accumulating over 28,850 thermal cycles. Ceramic interface forces were found to be the significant factor in limiting stator life rather than the scatter in material strength properties or the variation in component defects encountered.

40 CFR 86.1333-2010 - Transient test cycle generation.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED) Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines; Gaseous and Particulate... cycles. The heavy-duty transient engine cycles for Otto-cycle and diesel engines are listed in appendix I...

40 CFR 86.1333-2010 - Transient test cycle generation.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED) Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines; Gaseous and Particulate... cycles. The heavy-duty transient engine cycles for Otto-cycle and diesel engines are listed in appendix I...

40 CFR 86.1333-2010 - Transient test cycle generation.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED) Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines; Gaseous and Particulate... cycles. The heavy-duty transient engine cycles for Otto-cycle and diesel engines are listed in appendix I...

Equipment for testing automotive lead/acid batteries under SAE J240a conditions

NASA Astrophysics Data System (ADS)

Hamilton, J. A.; Rand, D. A. J.

Battery cycling equipment has been designed and constructed to test lead/acid batteries according to the American Society of Automotive Engineers' (SAE) J240a Standard. This life test simulates automotive service where the battery operates in a voltage-regulated charging system. The CSIRO design uses a master/slave concept to reduce both construction time and cost.

Examination of the Benefits of Standardized Interfaces on Space Systems

DTIC Science & Technology

2015-09-01

them to enter the once impenetrable aerospace market: Elon Musk with Space Exploration Technologies (SpaceX), Richard Branson with Virgin Galactic, and...systems-engineering- guide/se-life cycle-building-blocks/concept-development/highlevel-conceptual- definition. Musk , Elon . 2009. Risky Business... Musk , 2009) Unknown effects of prolonged exposure to radiation Degraded system capability (JPL 2015) Replenishment of the system capability may

Carbon Mitigation Impacts of Increased Softwood Lumber and Structural Panel Use for Nonresidential Construction in the United States

Treesearch

Prakash Nepal; Kenneth E. Skog; David B. McKeever; Richard D. Bergman; Karen L. Abt; Robert C. Abt

2016-01-01

More wood use in the United States to construct low-rise nonresidential (NR) buildings would increase consumption and production of softwood (SW) lumber, engineered wood products, and structural and nonstructural wood panels. Using a consequential life-cycle analysis, we estimated the change in net CO2 emissions thatwould be caused by increased...

An Incremental Life-cycle Assurance Strategy for Critical System Certification

DTIC Science & Technology

2014-11-04

for Safe Aircraft Operation Embedded software systems introduce a new class of problems not addressed by traditional system modeling & analysis...Platform Runtime Architecture Application Software Embedded SW System Engineer Data Stream Characteristics Latency jitter affects control behavior...do system level failures still occur despite fault tolerance techniques being deployed in systems ? Embedded software system as major source of

Computer-Aided Group Problem Solving for Unified Life Cycle Engineering (ULCE)

DTIC Science & Technology

1989-02-01

defining the problem, generating alternative solutions, evaluating alternatives, selecting alternatives, and implementing the solution. Systems...specialist in group dynamics, assists the group in formulating the problem and selecting a model framework. The analyst provides the group with computer...allocating resources, evaluating and selecting options, making judgments explicit, and analyzing dynamic systems. c. University of Rhode Island Drs. Geoffery

A life cycle assessment of distributed energy production from organic waste: Two case studies in Europe.

PubMed

Evangelisti, Sara; Clift, Roland; Tagliaferri, Carla; Lettieri, Paola

2017-06-01

By means of the life cycle assessment methodology, the purpose of this study is to assess the environmental impact when biomethane from organic waste produced at residential level is used to supply energy to a group of dwellings in the distributed generation paradigm. Three different Combined Heat and Power systems, such as fuel cells, Stirling engine and micro gas turbine, installed at household level are assessed in two different settings: one in Northern Europe (UK) and one in Southern Europe (Italy). Different operating strategies are investigated for each technology. Moreover, marginal electricity production technologies are analysed to assess their influence on the results. This study has demonstrated that the type of bio-methane fed micro-CHP technology employed has a significantly different environmental impact: fuel cells are the most environmentally friendly solution in every category analysed; Stirling engines, although can supply heat to the largest number of dwellings are the least environmentally friendly technology. However, key factors investigated in the model presented in this paper influence the decision making on the type of technology adopted and the operating strategy to be implemented. Copyright © 2017 Elsevier Ltd. All rights reserved.

Techno-economic and life-cycle assessment of an attached growth algal biorefinery.

PubMed

Barlow, Jay; Sims, Ronald C; Quinn, Jason C

2016-11-01

This study examined the sustainability of generating renewable diesel via hydrothermal liquefaction (HTL) of biomass from a rotating algal biofilm reactor. Pilot-scale growth studies and laboratory-scale HTL experiments were used to validate an engineering system model. The engineering system model served as the foundation to evaluate the economic feasibility and environmental impact of the system at full scale. Techno-economic results indicate that biomass feedstock costs dominated the minimum fuel selling price (MFSP), with a base case of $104.31per gallon. Life-cycle assessment results show a base-case global warming potential (GWP) of 80gCO2-eMJ(-1) and net energy ratio (NER) of 1.65 based on a well-to-product system boundary. Optimization of the system reduces MFSP, GWP and NER to $11.90Gal(-1), -44gCO2-eMJ(-1), and 0.33, respectively. The systems-level impacts of integrating algae cultivation with wastewater treatment were found to significantly reduce environmental impact. Sensitivity analysis showed that algal productivity most significantly affected fuel selling price, emphasizing the importance of optimizing biomass productivity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Overexpression of NAC gene from Lepidium latifolium L. enhances biomass, shortens life cycle and induces cold stress tolerance in tobacco: potential for engineering fourth generation biofuel crops.

PubMed

Grover, Atul; Singh, Sadhana; Pandey, Pankaj; Patade, Vikas Yadav; Gupta, Sanjay Mohan; Nasim, M

2014-11-01

We report elevated biomass and altered growth characteristics of tobacco plants up on transformation with a NAC (NAM, ATAF1/2,CUC2) gene (GenBank Accession FJ754254) isolated from Lepidium latifolium L. (LlaNAC). Transgenic plants showed significant differences in fresh weight, midrib length of longest leaf, leaf area, height of the plant, root and shoot weights, etc. during vegetative phase. On 100th day after sowing (DAS), plants of transgenic lines were 2-3 times taller than the wild type plants, though no significant difference was recorded in moisture contents of any of the plant tissues. Over-expression of NAC gene up to 2,000 fold was recorded in leaves of transgenic plants on 100th DAS. Interestingly, transgenic plants showed significantly shortened (P(t) = 0.02-0.04) life cycle, as they showed a completely altered growth behaviour. Transgenic plants entered reproductive phase earlier by 60 days, with lines NC2 and NC7b entering first, followed by line NC10. However, the time period spent in the reproductive phase by the plant was nearly twice in case of transgenic lines NC2, NC7b and NC10, as compared to the wild type plants. Despite that, these lines completed their life cycle in 45-60 days lesser than the time taken by wild-type tobacco plants. No difference was recorded in fruit and seed yield of transgenic or wild type plants. To the best of our knowledge, this is the first report on over-expression of NAC gene causing altered growth and biomass patterns. We expect this study to become an important reference towards future engineering of plants for fuel and fodder purposes.

Development of improved-durability plasma sprayed ceramic coatings for gas turbine engines

NASA Technical Reports Server (NTRS)

Sumner, I. E.; Ruckle, D. L.

1980-01-01

As part of a NASA program to reduce fuel consumption of current commercial aircraft engines, methods were investigated for improving the durability of plasma sprayed ceramic coatings for use on vane platforms in the JT9D turbofan engine. Increased durability concepts under evaluation include use of improved strain tolerant microstructures and control of the substrate temperature during coating application. Initial burner rig tests conducted at temperatures of 1010 C (1850 F) indicate that improvements in cyclic life greater than 20:1 over previous ceramic coating systems were achieved. Three plasma sprayed coating systems applied to first stage vane platforms in the high pressure turbine were subjected to a 100-cycle JT9D engine endurance test with only minor damage occurring to the coatings.

Preliminary study of advanced turboprop and turboshaft engines for light aircraft. [cost effectiveness

NASA Technical Reports Server (NTRS)

Knip, G.; Plencner, R. M.; Eisenberg, J. D.

1980-01-01

The effects of engine configuration, advanced component technology, compressor pressure ratio and turbine rotor-inlet temperature on such figures of merit as vehicle gross weight, mission fuel, aircraft acquisition cost, operating, cost and life cycle cost are determined for three fixed- and two rotary-wing aircraft. Compared with a current production turboprop, an advanced technology (1988) engine results in a 23 percent decrease in specific fuel consumption. Depending on the figure of merit and the mission, turbine engine cost reductions required to achieve aircraft cost parity with a current spark ignition reciprocating (SIR) engine vary from 0 to 60 percent and from 6 to 74 percent with a hypothetical advanced SIR engine. Compared with a hypothetical turboshaft using currently available technology (1978), an advanced technology (1988) engine installed in a light twin-engine helicopter results in a 16 percent reduction in mission fuel and about 11 percent in most of the other figures of merit.

Life Support Goals Including High Closure and Low Mass Should Be Reconsidered Using Systems Analysis

NASA Technical Reports Server (NTRS)

Jones, Harry W.

2017-01-01

Recycling space life support systems have been built and tested since the 1960s and have operated on the International Space Station (ISS) since the mid 2000s. The development of space life support has been guided by a general consensus focused on two important related goals, increasing system closure and reducing launch mass. High closure is achieved by recycling crew waste products such as carbon dioxide and condensed humidity. Recycling directly reduces the mass of oxygen and water for the crew that must be launched from Earth. The launch mass of life support can be further reduced by developing recycling systems with lower hardware mass and reduced power. The life support consensus has also favored using biological systems. The goal of increasing closure using biological systems suggests that food should be grown in space and that biological processors be used for air, water, and waste recycling. The goal of reducing launch mass led to use of Equivalent System Mass (ESM) in life support advocacy and technology selection. The recent consensus assumes that the recycling systems architecture developed in the 1960s and implemented on ISS will be used on all future long missions. NASA and other project organizations use the standard systems engineering process to guide hardware development. The systems process was used to develop ISS life support, but it has been less emphasized in planning future systems for the moon and Mars. Since such missions are far in the future, there has been less immediate need for systems engineering analysis to consider trade-offs, reliability, and Life Cycle Cost (LCC). Preliminary systems analysis suggests that the life support consensus concepts should be revised to reflect systems engineering requirements.

Exergetic life cycle assessment of hydrogen production from renewables

NASA Astrophysics Data System (ADS)

Granovskii, Mikhail; Dincer, Ibrahim; Rosen, Marc A.

Life cycle assessment is extended to exergetic life cycle assessment and used to evaluate the exergy efficiency, economic effectiveness and environmental impact of producing hydrogen using wind and solar energy in place of fossil fuels. The product hydrogen is considered a fuel for fuel cell vehicles and a substitute for gasoline. Fossil fuel technologies for producing hydrogen from natural gas and gasoline from crude oil are contrasted with options using renewable energy. Exergy efficiencies and greenhouse gas and air pollution emissions are evaluated for all process steps, including crude oil and natural gas pipeline transportation, crude oil distillation and natural gas reforming, wind and solar electricity generation, hydrogen production through water electrolysis, and gasoline and hydrogen distribution and utilization. The use of wind power to produce hydrogen via electrolysis, and its application in a fuel cell vehicle, exhibits the lowest fossil and mineral resource consumption rate. However, the economic attractiveness, as measured by a "capital investment effectiveness factor," of renewable technologies depends significantly on the ratio of costs for hydrogen and natural gas. At the present cost ratio of about 2 (per unit of lower heating value or exergy), capital investments are about five times lower to produce hydrogen via natural gas rather than wind energy. As a consequence, the cost of wind- and solar-based electricity and hydrogen is substantially higher than that of natural gas. The implementation of a hydrogen fuel cell instead of an internal combustion engine permits, theoretically, an increase in a vehicle's engine efficiency of about of two times. Depending on the ratio in engine efficiencies, the substitution of gasoline with "renewable" hydrogen leads to (a) greenhouse gas (GHG) emissions reductions of 12-23 times for hydrogen from wind and 5-8 times for hydrogen from solar energy, and (b) air pollution (AP) emissions reductions of 38-76 times for hydrogen from wind and 16-32 times for hydrogen from solar energy. By comparison, substitution of gasoline with hydrogen from natural gas allows reductions in GHG emissions only as a result of the increased efficiency of a fuel cell engine, and a reduction of AP emissions of 2.5-5 times. These data suggest that "renewable" hydrogen represents a potential long-term solution to many environmental problems.

Water Use in the US Electric Power Sector: Energy Systems ...

EPA Pesticide Factsheets

This presentation reviews the water demands of long-range electricity scenarios. It addresses questions such as: What are the aggregate water requirements of the U.S. electric power sector? How could water requirements evolve under different long-range regional generation mixes? It also looks at research addressing the electricity generation water demand from a life cycle perspective, such as water use for the fuel cycle (natural gas, coal, uranium, etc.) and water use for the materials/equipment/manufacturing of new power plants. The presentation is part of panel session on the Water-Energy Nexus at the World Energy Engineering Congress

Viscoplastic analysis of an experimental cylindrical thrust chamber liner

NASA Technical Reports Server (NTRS)

Arya, Vinod K.; Arnold, Steven M.

1991-01-01

A viscoplastic stress-strain analysis of an experimental cylindrical thrust chamber is presented. A viscoelastic constitutive model incorporating a single internal state variable that represents kinematic hardening was employed to investigate whether such a viscoplastic model could predict the experimentally observed behavior of the thrust chamber. Two types of loading cycles were considered: a short cycle of 3.5 sec. duration that corresponded to the experiments, and an extended loading cycle of 485.1 sec. duration that is typical of the Space Shuttle Main Engine (SSME) operating cycle. The analysis qualitatively replicated the deformation behavior of the component as observed in experiments designed to simulate SSME operating conditions. The analysis also showed that the mode and location in the component may depend on the loading cycle. The results indicate that using viscoplastic models for structural analysis can lead to a more realistic life assessment of thrust chambers.

An overview of the small engine component technology (SECT) studies. [commuter, rotorcraft, cruise missile and auxiliary power applications in year 2000

NASA Technical Reports Server (NTRS)

Vanco, M. R.; Wintucky, W. T.; Niedwiecki, R. W.

1986-01-01

The objectives of the joint NASA/Army SECT studies were to identify high payoff technologies for year 2000 small gas turbine engine applications and to provide a technology plan for guiding future research and technology efforts applicable to rotorcraft, commuter and general aviation aircraft and cruise missiles. Competitive contracts were awarded to Allison, AVCO Lycoming, Garrett, Teledyne CAE and Williams International. This paper presents an overview of the contractors' study efforts for the commuter, rotorcraft, cruise missile, and auxiliary power (APU) applications with engines in the 250 to 1,000 horsepower size range. Reference aircraft, missions and engines were selected. Advanced engine configurations and cycles with projected year 2000 component technologies were evaluated and compared with a reference engine selected by the contractor. For typical commuter and rotorcraft applications, fuel savings of 22 percent to 42 percent can be attained. For $1/gallon and $2/gallon fuel, reductions in direct operating cost range from 6 percent to 16 percent and from 11 percent to 17 percent respectively. For subsonic strategic cruise missile applications, fuel savings of 38 percent to 54 percent can be achieved which allows 35 percent to 60 percent increase in mission range and life cycle cost reductions of 40 percent to 56 percent. High payoff technologies have been identified for all applications.

Fatigue life analysis for traction drives with application to a toroidal type geometry

NASA Technical Reports Server (NTRS)

Coy, J. J.; Loewenthal, S. H.; Zaretsky, E. V.

1976-01-01

A contact fatigue life analysis for traction drives was developed which was based on a modified Lundberg-Palmgren theory. The analysis was used to predict life for a cone-roller toroidal traction drive. A 90-percent probability of survival was assumed for the calculated life. Parametric results were presented for life and Hertz contact stress as a function of load, drive ratio, and size. A design study was also performed. The results were compared to previously published work for the dual cavity toroidal drive as applied to a typical compact passenger vehicle drive train. For a representative duty cycle condition wherein the engine delivers 29 horsepower at 2000 rpm with the vehicle moving at 48.3 km/hr (30 mph) the drive life was calculated to be 19,200 km (11 900 miles).

Advanced Control Considerations for Turbofan Engine Design

NASA Technical Reports Server (NTRS)

Connolly, Joseph W.; Csank, Jeffrey T.; Chicatelli, Amy

2016-01-01

This paper covers the application of a model-based engine control (MBEC) methodology featuring a self tuning on-board model for an aircraft turbofan engine simulation. The nonlinear engine model is capable of modeling realistic engine performance, allowing for a verification of the advanced control methodology over a wide range of operating points and life cycle conditions. The on-board model is a piece-wise linear model derived from the nonlinear engine model and updated using an optimal tuner Kalman Filter estimation routine, which enables the on-board model to self-tune to account for engine performance variations. MBEC is used here to show how advanced control architectures can improve efficiency during the design phase of a turbofan engine by reducing conservative operability margins. The operability margins that can be reduced, such as stall margin, can expand the engine design space and offer potential for efficiency improvements. Application of MBEC architecture to a nonlinear engine simulation is shown to reduce the thrust specific fuel consumption by approximately 1% over the baseline design, while maintaining safe operation of the engine across the flight envelope.

Life-Cycle Cost Analysis for Small Unmanned Aircraft Systems Deployed Aboard Coast Guard Cutters

DTIC Science & Technology

2013-12-09

safest way to survey the NBC disaster site. “Swarms could scan high-risk buildings and sites (think Fukushima ^Åèìáëáíáçå=oÉëÉ~êÅÜ=mêçÖê~ã= dê~Çì~íÉ...in 1997 with a degree in mechanical engineering. After graduation, he served onboard USCGC Thetis (WMEC-910) as the student engineer and damage...the surrounding area with his family. After graduation in December 2013, he will report to the In-Service Vessel Sustainment Project as assistant

Software-Engineering Process Simulation (SEPS) model

NASA Technical Reports Server (NTRS)

Lin, C. Y.; Abdel-Hamid, T.; Sherif, J. S.

1992-01-01

The Software Engineering Process Simulation (SEPS) model is described which was developed at JPL. SEPS is a dynamic simulation model of the software project development process. It uses the feedback principles of system dynamics to simulate the dynamic interactions among various software life cycle development activities and management decision making processes. The model is designed to be a planning tool to examine tradeoffs of cost, schedule, and functionality, and to test the implications of different managerial policies on a project's outcome. Furthermore, SEPS will enable software managers to gain a better understanding of the dynamics of software project development and perform postmodern assessments.

Highly efficient 6-stroke engine cycle with water injection

DOEpatents

Szybist, James P; Conklin, James C

2012-10-23

A six-stroke engine cycle having improved efficiency. Heat is recovered from the engine combustion gases by using a 6-stroke engine cycle in which combustion gases are partially vented proximate the bottom-dead-center position of the fourth stroke cycle, and water is injected proximate the top-dead-center position of the fourth stroke cycle.

40 CFR 89.410 - Engine test cycle.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine test cycle. 89.410 Section 89... Procedures § 89.410 Engine test cycle. (a) Emissions shall be measured using one of the test cycles specified...) through (a)(4) of this section. These cycles shall be used to test engines on a dynamometer. (1) The 8...

Orbital Transfer Vehicle (OTV) engine study. Phase A: Extension

NASA Technical Reports Server (NTRS)

Sobin, A. J.

1980-01-01

The current Phase A-Extension of the OTV engine study program aims to provide additional expander and staged combustion cycle data that will lead to design definition of the OTV engine. The proposed program effort seeks to optimize the expander cycle engine concept (consistent with identified OTV engine requirements), investigate the feasibility of kitting the staged combustion cycle engine to provide extended thrust operation, and conduct in-depth analysis of development risk, crew safety, and reliability for both cycles. Additional tasks address the costing of a 10/K thrust expander cycle engine and support of OTV systems study contractors.

40 CFR Appendix II to Part 1039 - Steady-State Duty Cycles

Code of Federal Regulations, 2011 CFR

2011-07-01

... Appendix II to Part 1039—Steady-State Duty Cycles (a) The following duty cycles apply for constant-speed engines: (1) The following duty cycle applies for discrete-mode testing: D2 mode number Engine speed...(seconds) Engine speed Torque(percent) 1, 2 1a Steady-state 53 Engine governed 100. 1b Transition 20 Engine...

Bending fatigue of electron-beam-welded foils. Application to a hydrodynamic air bearing in the Chrysler/DOE upgraded automotive gas tubine engine

NASA Technical Reports Server (NTRS)

Saltsman, J. F.; Halford, G. R.

1984-01-01

A hydrodynamic air bearing with a compliment surface is used in the gas generator of an upgraded automotive gas turbine engine. In the prototype design, the compliant surface is a thin foil spot welded at one end to the bearing cartridge. During operation, the foil failed along the line of spot welds which acted as a series of stress concentrators. Because of its higher degree of geometric uniformity, electron beam welding of the foil was selected as an alternative to spot welding. Room temperature bending fatigue tests were conducted to determine the fatigue resistance of the electron beam welded foils. Equations were determined relating cycles to crack initiation and cycles to failure to nominal total strain range. A scaling procedure is presented for estimating the reduction in cyclic life when the foil is at its normal operating temperature of 260 C (500 F).

401. Westinghouse plans a smaller 501

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barker, T.

1996-11-01

In concept, the recently announced 84-MW Westinghouse 401 is a smaller-scale 501G heavy-frame gas turbine. (The scaling factor is 0.64:1.) It will share design features with the larger 501F and G, including a two-bearing rotor, horizontally-split casing, cold-end drive, and axial exhaust, but there will be no common components apart from some nuts and bolts. From a marketing standpoint, the new 84-MW engine is intended to occupy the market niche between the 110-MW 501 D, and the 49-MW 251B11/12. The engineers` design goals, as always, were high combined cycle efficiency, low life cycle cost and low cost of electricity, allmore » good reasons for working from the proven and successful 501s. The first 401 is scheduled to be shipped from Westinghouse`s Hamilton, Ontario, Canada plant in March 1998. 2 figs.« less

Aerothermal modeling. Executive summary

NASA Technical Reports Server (NTRS)

Kenworthy, M. K.; Correa, S. M.; Burrus, D. L.

1983-01-01

One of the significant ways in which the performance level of aircraft turbine engines has been improved is by the use of advanced materials and cooling concepts that allow a significant increase in turbine inlet temperature level, with attendant thermodynamic cycle benefits. Further cycle improvements have been achieved with higher pressure ratio compressors. The higher turbine inlet temperatures and compressor pressure ratios with corresponding higher temperature cooling air has created a very hostile environment for the hot section components. To provide the technology needed to reduce the hot section maintenance costs, NASA has initiated the Hot Section Technology (HOST) program. One key element of this overall program is the Aerothermal Modeling Program. The overall objective of his program is to evolve and validate improved analysis methods for use in the design of aircraft turbine engine combustors. The use of such combustor analysis capabilities can be expected to provide significant improvement in the life and durability characteristics of both combustor and turbine components.

New type of microengine using internal combustion of hydrogen and oxygen

NASA Astrophysics Data System (ADS)

Svetovoy, Vitaly B.; Sanders, Remco G. P.; Ma, Kechun; Elwenspoek, Miko C.

2014-03-01

Microsystems become part of everyday life but their application is restricted by lack of strong and fast motors (actuators) converting energy into motion. For example, widespread internal combustion engines cannot be scaled down because combustion reactions are quenched in a small space. Here we present an actuator with the dimensions 100 × 100 × 5 μm3 that is using internal combustion of hydrogen and oxygen as part of its working cycle. Water electrolysis driven by short voltage pulses creates an extra pressure of 0.5-4 bar for a time of 100-400 μs in a chamber closed by a flexible membrane. When the pulses are switched off this pressure is released even faster allowing production of mechanical work in short cycles. We provide arguments that this unexpectedly fast pressure decrease is due to spontaneous combustion of the gases in the chamber. This actuator is the first step to truly microscopic combustion engines.

Near term hybrid passenger vehicle development program, phase 1

NASA Technical Reports Server (NTRS)

1980-01-01

Missions for hybrid vehicles that promise to yield high petroleum impact were identified and a preliminary design, was developed that satisfies the mission requirements and performance specifications. Technologies that are critical to successful vehicle design, development and fabrication were determined. Trade-off studies to maximize fuel savings were used to develop initial design specifications of the near term hybrid vehicle. Various designs were "driven" through detailed computer simulations which calculate the petroleum consumption in standard driving cycles, the petroleum and electricity consumptions over the specified missions, and the vehicle's life cycle costs over a 10 year vehicle lifetime. Particular attention was given to the selection of the electric motor, heat engine, drivetrain, battery pack and control system. The preliminary design reflects a modified current compact car powered by a currently available turbocharged diesel engine and a 24 kW (peak) compound dc electric motor.

Concept definition study of small Brayton cycle engines for dispersed solar electric power systems

NASA Technical Reports Server (NTRS)

Six, L. D.; Ashe, T. L.; Dobler, F. X.; Elkins, R. T.

1980-01-01

Three first-generation Brayton cycle engine types were studied for solar application: a near-term open cycle (configuration A), a near-term closed cycle (configuration B), and a longer-term open cycle (configuration C). A parametric performance analysis was carried out to select engine designs for the three configurations. The interface requirements for the Brayton cycle engine/generator and solar receivers were determined. A technology assessment was then carried out to define production costs, durability, and growth potential for the selected engine types.

Status of Brayton Cycle Power Conversion Development at NASA GRC

NASA Technical Reports Server (NTRS)

Mason, Lee S.; Shaltens, Richard K.; Dolce, James L.; Cataldo, Robert L.

2002-01-01

The NASA Glenn Research Center (GRC) is pursuing the development of Brayton cycle power conversion for various NASA initiatives. Brayton cycle power systems offer numerous advantages for space power generation including high efficiency, long life, high maturity, and broad scalability. Candidate mission applications include surface rovers and bases, advanced propulsion vehicles, and earth orbiting satellites. A key advantage is the ability for Brayton converters to span the wide range of power demands of future missions from several kilowatts to multi-megawatts using either solar, isotope, or reactor heat sources. Brayton technology has been under development by NASA since the early 1960's resulting in engine prototypes in the 2 to 15 kW-class that have demonstrated conversion efficiency of almost 30% and cumulative operation in excess of 40,000 hours. Present efforts at GRC are focusing on a 2 kW testbed as a proving ground for future component advances and operational strategies, and a 25 kW engine design as a modular building block for 100 kW-class electric propulsion and Mars surface power applications.

Qualification of Engineering Camera for Long-Duration Deep Space Missions

NASA Technical Reports Server (NTRS)

Ramesham, Rajeshuni; Maki, Justin N.; Pourangi, Ali M.; Lee, Steven W.

2012-01-01

Qualification and verification of advanced electronic packaging and interconnect technologies, and various other types of hardware elements for the Mars Exploration Rover s Spirit and Opportunity (MER)/Mars Science Laboratory (MSL) flight projects, has been performed to enhance the mission assurance. The qualification of hardware (engineering camera) under extreme cold temperatures has been performed with reference to various Mars-related project requirements. The flight-like packages, sensors, and subassemblies have been selected for the study to survive three times the total number of expected diurnal temperature cycles resulting from all environmental and operational exposures occurring over the life of the flight hardware, including all relevant manufacturing, ground operations, and mission phases. Qualification has been performed by subjecting above flight-like hardware to the environmental temperature extremes, and assessing any structural failures or degradation in electrical performance due to either overstress or thermal cycle fatigue. Engineering camera packaging designs, charge-coupled devices (CCDs), and temperature sensors were successfully qualified for MER and MSL per JPL design principles. Package failures were observed during qualification processes and the package redesigns were then made to enhance the reliability and subsequent mission assurance. These results show the technology certainly is promising for MSL, and especially for longterm extreme temperature missions to the extreme temperature conditions. The engineering camera has been completely qualified for the MSL project, with the proven ability to survive on Mars for 2010 sols, or 670 sols times three. Finally, the camera continued to be functional, even after 2010 thermal cycles.

New Methods in Tissue Engineering: Improved Models for Viral Infection.

PubMed

Ramanan, Vyas; Scull, Margaret A; Sheahan, Timothy P; Rice, Charles M; Bhatia, Sangeeta N

2014-11-01

New insights in the study of virus and host biology in the context of viral infection are made possible by the development of model systems that faithfully recapitulate the in vivo viral life cycle. Standard tissue culture models lack critical emergent properties driven by cellular organization and in vivo-like function, whereas animal models suffer from limited susceptibility to relevant human viruses and make it difficult to perform detailed molecular manipulation and analysis. Tissue engineering techniques may enable virologists to create infection models that combine the facile manipulation and readouts of tissue culture with the virus-relevant complexity of animal models. Here, we review the state of the art in tissue engineering and describe how tissue engineering techniques may alleviate some common shortcomings of existing models of viral infection, with a particular emphasis on hepatotropic viruses. We then discuss possible future applications of tissue engineering to virology, including current challenges and potential solutions.

New Methods in Tissue Engineering

PubMed Central

Sheahan, Timothy P.; Rice, Charles M.; Bhatia, Sangeeta N.

2015-01-01

New insights in the study of virus and host biology in the context of viral infection are made possible by the development of model systems that faithfully recapitulate the in vivo viral life cycle. Standard tissue culture models lack critical emergent properties driven by cellular organization and in vivo–like function, whereas animal models suffer from limited susceptibility to relevant human viruses and make it difficult to perform detailed molecular manipulation and analysis. Tissue engineering techniques may enable virologists to create infection models that combine the facile manipulation and readouts of tissue culture with the virus-relevant complexity of animal models. Here, we review the state of the art in tissue engineering and describe how tissue engineering techniques may alleviate some common shortcomings of existing models of viral infection, with a particular emphasis on hepatotropic viruses. We then discuss possible future applications of tissue engineering to virology, including current challenges and potential solutions. PMID:25893203

A Framework for Performing Verification and Validation in Reuse Based Software Engineering

NASA Technical Reports Server (NTRS)

Addy, Edward A.

1997-01-01

Verification and Validation (V&V) is currently performed during application development for many systems, especially safety-critical and mission- critical systems. The V&V process is intended to discover errors, especially errors related to critical processing, as early as possible during the development process. The system application provides the context under which the software artifacts are validated. This paper describes a framework that extends V&V from an individual application system to a product line of systems that are developed within an architecture-based software engineering environment. This framework includes the activities of traditional application-level V&V, and extends these activities into domain engineering and into the transition between domain engineering and application engineering. The framework includes descriptions of the types of activities to be performed during each of the life-cycle phases, and provides motivation for the activities.

Service Modeling for Service Engineering

NASA Astrophysics Data System (ADS)

Shimomura, Yoshiki; Tomiyama, Tetsuo

Intensification of service and knowledge contents within product life cycles is considered crucial for dematerialization, in particular, to design optimal product-service systems from the viewpoint of environmentally conscious design and manufacturing in advanced post industrial societies. In addition to the environmental limitations, we are facing social limitations which include limitations of markets to accept increasing numbers of mass-produced artifacts and such environmental and social limitations are restraining economic growth. To attack and remove these problems, we need to reconsider the current mass production paradigm and to make products have more added values largely from knowledge and service contents to compensate volume reduction under the concept of dematerialization. Namely, dematerialization of products needs to enrich service contents. However, service was mainly discussed within marketing and has been mostly neglected within traditional engineering. Therefore, we need new engineering methods to look at services, rather than just functions, called "Service Engineering." To establish service engineering, this paper proposes a modeling technique of service.

Aerojet advanced engine concept

NASA Technical Reports Server (NTRS)

Schoenman, L.

1984-01-01

The future orbit transfer vehicle (OTV) requirements which dictate the need for a highly versatile, highly reliable, reusable propulsion module are discussed. To attain maximum operational economy, space-basing is essential. This requires a reusable, maintenance free engine. The design features of this space based engine are defined. A new engine cycle and its advantages allow all the maintenance goals to be attained. Rubbing contact and interpropellant seals and purges are eliminated when GO2 is used to drive the LO2 pump. The TPA design has only one moving part. The use of both GH2 and GO2 to drive the turbines lowers the turbine temperatures in addition lower GH2 temperatures and pressures improve chamber cooling and longer life. The use of GO2 as a turbine drive fluid is addressed. Space based engines require an integrated control and health monitoring system to improve system reliability and eliminate all scheduled maintenance. It is concluded that all OTV propulsion requirements can be fulfilled with a single engine. The technological developments required to demonstrate that engine are outlined.

Mathematical modeling and characteristic analysis for over-under turbine based combined cycle engine

NASA Astrophysics Data System (ADS)

Ma, Jingxue; Chang, Juntao; Ma, Jicheng; Bao, Wen; Yu, Daren

2018-07-01

The turbine based combined cycle engine has become the most promising hypersonic airbreathing propulsion system for its superiority of ground self-starting, wide flight envelop and reusability. The simulation model of the turbine based combined cycle engine plays an important role in the research of performance analysis and control system design. In this paper, a turbine based combined cycle engine mathematical model is built on the Simulink platform, including a dual-channel air intake system, a turbojet engine and a ramjet. It should be noted that the model of the air intake system is built based on computational fluid dynamics calculation, which provides valuable raw data for modeling of the turbine based combined cycle engine. The aerodynamic characteristics of turbine based combined cycle engine in turbojet mode, ramjet mode and mode transition process are studied by the mathematical model, and the influence of dominant variables on performance and safety of the turbine based combined cycle engine is analyzed. According to the stability requirement of thrust output and the safety in the working process of turbine based combined cycle engine, a control law is proposed that could guarantee the steady output of thrust by controlling the control variables of the turbine based combined cycle engine in the whole working process.

Orbit transfer vehicle advanced expander cycle engine point design study. Volume 2: Study results

NASA Technical Reports Server (NTRS)

Diem, H. G.

1980-01-01

The design characteristics of the baseline engine configuration of the advanced expander cycle engine are described. Several aspects of engine optimization are considered which directly impact the design of the baseline thrust chamber. Four major areas of the power cycle optimization are emphasized: main turbine arrangement; cycle engine source; high pressure pump design; and boost pump drive.

Fiber reinforced superalloys for rocket engines

NASA Technical Reports Server (NTRS)

Petrasek, Donald W.; Stephens, Joseph R.

1989-01-01

High pressure turbopumps for advanced reusable liquid propellant rocket engines such as that for the Space Shuttle Main Engine (SSME) require turbine blade materials that operate under extreme conditions of temperature, hydrogen environment, high-cycle fatigue loading, thermal fatigue and thermal shock. Such requirements tax the capabilities of current blade materials. Based on projections of properties for tungsten fiber reinforced superalloy (FRS) composites, it was concluded that FRS turbine blades offer the potential of a several fold increase in life and over a 200 C increase in temperature capability over the current SSME blade material. FRS composites were evaluated with respect to mechanical property requirements for SSME blade applications. Compared to the current blade material, the thermal shock resistance of FRS materials is excellent, two to nine times better, and their thermal fatigue resistance is equal to or higher than the current blade material. FRS materials had excellent low and high-cycle fatigue strengths, and thermal shock-induced surface microcracks had no influence on their fatigue strength. The material also exhibited negligible embrittlement when exposed to a hydrogen environment.

Fiber reinforced superalloys for rocket engines

NASA Technical Reports Server (NTRS)

Petrasek, Donald W.; Stephens, Joseph R.

1988-01-01

High-pressure turbopumps for advanced reusable liquid-propellant rocket engines such as that for the Space Shuttle Main Engine (SSME) require turbine blade materials that operate under extreme conditions of temperature, hydrogen environment, high-cycle fatigue loading, thermal fatigue and thermal shock. Such requirements tax the capabilities of current blade materials. Based on projections of properties for tungsten fiber reinforced superalloy (FRS) composites, it was concluded that FRS turbine blades offer the potential of a several-fold increase in life and over a 200C increase in temperature capability over current SSME blade material. FRS composites were evaluated with respect to mechanical property requirements for SSME blade applications. Compared to the current blade material, the thermal shock resistance of FRS materials is excellent, two to nine times better, and their thermal fatigue resistance is equal to or higher than the current blade material. FRS materials had excellent low and high-cycle fatigue strengths, and thermal shock-induced surface microcracks had no influence on their fatigue strength. The material also exhibited negligible embrittlement when exposed to a hydrogen environment.

Toward an Ontological Approach in Goal-Oriented Language Courseware Design and Its Implications for Technology-Independent Content Structuring

ERIC Educational Resources Information Center

Colpaert, Jozef

2006-01-01

The term "design" is being understood more and more as a methodological process, together with its acceptance as the result of such a process. As a process, it is a stage in the courseware engineering life cycle which primarily focuses on rendering the development process more effective and on enhancing the qualities of the finished system,…

Composite Aircraft Life Cycle Cost Estimating Model

DTIC Science & Technology

2011-03-01

X. The masked fit of the lines are as follows: • Part Count Percentage Reduction for Design hours ( HRE %) = • Part Count Percentage Reduction...multiplied by the respective labor rate (LR). Currently, CT is a percentage of total non- recurring development cost. HRE corresponds to recurring...Empty Weight Velocity RENGR HRE CRE 46 Figure 14: Non-Recurring Engineering CER Currently, CT is a percentage of non-recurring development

Cradle-to-Gate Life-Cycle Inventory of Hardboard and Engineered Wood Siding and Trim Produced in North America

Treesearch

Richard D. Bergman

2015-01-01

Developing wood product LCI data helps construct product LCAs that are then incorporated into developing whole building LCAs in environmental footprint software such as the Athena Impact Estimator for Buildings (ASMI 2015). Conducting whole building LCAs provide for points that go toward green building certification in rating systems such as LEED v4, Green Globes, and...

Software Requirements Specification for an Ammunition Management System

DTIC Science & Technology

1986-09-01

thesis takes the form of a software requirements specification. Such a specification, according to Pressman [Ref. 7], establishes a complete...defined by Pressman , is depicted in Figure 1.1. 11 Figure 1.1 Generalized Software Life Cycle The common thread which binds the various phases together...application of software engineering principles requires an established methodology. This methodology, according to Pressman [Ref. 8:p. 151 is an

Process Improvement Should Link to Security: SEPG 2007 Security Track Recap

DTIC Science & Technology

2007-09-01

the Systems Security Engineering Capability Maturity Model (SSE- CMM / ISO 21827) and its use in system software developments ...software development life cycle ( SDLC )? 6. In what ways should process improvement support security in the SDLC ? 1.2 10BPANEL RESOURCES For each... project management, and support practices through the use of the capability maturity models including the CMMI and the Systems Security

Development and Application of an Approach to Optimize Renewable Energy Systems in Afghanistan

DTIC Science & Technology

2012-06-01

upon renewable energy sources for power production , the more desirable the system design. Total operations and maintenance cost has the third...Engineers (USACE) practices for implementing energy systems for ANSF infrastructure are limited to diesel generators, and, thus, preclude alternative...system attribute values: total O&M cost, renewable fraction, generator production , wind production , solar production , battery quantity, life cycle

Reference Model for Project Support Environments Version 1.0

DTIC Science & Technology

1993-02-28

relationship with the framework’s Process Support services and with the Lifecycle Process Engineering services. Examples: "* ORCA (Object-based...Design services. Examples: "* ORCA (Object-based Requirements Capture and Analysis). "* RETRAC (REquirements TRACeability). 4.3 Life-Cycle Process...34traditional" computer tools. Operations: Examples of audio and video processing operations include: "* Create, modify, and delete sound and video data

Knowledge-Based Aircraft Automation: Managers Guide on the use of Artificial Intelligence for Aircraft Automation and Verification and Validation Approach for a Neural-Based Flight Controller

NASA Technical Reports Server (NTRS)

Broderick, Ron

1997-01-01

The ultimate goal of this report was to integrate the powerful tools of artificial intelligence into the traditional process of software development. To maintain the US aerospace competitive advantage, traditional aerospace and software engineers need to more easily incorporate the technology of artificial intelligence into the advanced aerospace systems being designed today. The future goal was to transition artificial intelligence from an emerging technology to a standard technology that is considered early in the life cycle process to develop state-of-the-art aircraft automation systems. This report addressed the future goal in two ways. First, it provided a matrix that identified typical aircraft automation applications conducive to various artificial intelligence methods. The purpose of this matrix was to provide top-level guidance to managers contemplating the possible use of artificial intelligence in the development of aircraft automation. Second, the report provided a methodology to formally evaluate neural networks as part of the traditional process of software development. The matrix was developed by organizing the discipline of artificial intelligence into the following six methods: logical, object representation-based, distributed, uncertainty management, temporal and neurocomputing. Next, a study of existing aircraft automation applications that have been conducive to artificial intelligence implementation resulted in the following five categories: pilot-vehicle interface, system status and diagnosis, situation assessment, automatic flight planning, and aircraft flight control. The resulting matrix provided management guidance to understand artificial intelligence as it applied to aircraft automation. The approach taken to develop a methodology to formally evaluate neural networks as part of the software engineering life cycle was to start with the existing software quality assurance standards and to change these standards to include neural network development. The changes were to include evaluation tools that can be applied to neural networks at each phase of the software engineering life cycle. The result was a formal evaluation approach to increase the product quality of systems that use neural networks for their implementation.

Life cycle comparison of fuel cell vehicles and internal combustion engine vehicles for Canada and the United States

NASA Astrophysics Data System (ADS)

Zamel, Nada; Li, Xianguo

The objective of this study is to put forward a full analysis of the impact of the difference between the Canadian and American energy realities on the life cycle of fuel cell vehicles and internal combustion engine vehicles. Electricity is a major type of energy used in the transportation sector. Electricity is needed in the production of feedstock of fuel, the production of the fuel, the production of the vehicle material and the assembly of the vehicles. Therefore, it is necessary to investigate the impact of the electricity mix difference between Canada and the United States. In the analysis, the life cycle of the fuel consists of obtaining the raw material, extracting the fuel from the raw material, transporting and storing the fuel as well as using the fuel in the vehicle. Four different methods of obtaining hydrogen were analyzed; using coal and nuclear power to produce electricity and extract hydrogen through electrolysis and via steam reforming of natural gas in a natural gas plant and in a hydrogen refueling station. It is found that fuel cell vehicle fuelled by hydrogen has lower energy consumption and greenhouse gas emissions than internal combustion engine vehicle fuelled by conventional gasoline except for hydrogen production using coal as the primary energy source in Canada and the United States. Using the Canadian electricity mix will result in lower carbon dioxide emissions and energy consumption than using the American electricity mix. For the present vehicles, using the Canadian electricity mix will save up to 215.18 GJ of energy and 20.87 t of CO 2 on a per capita basis and 26.53 GJ of energy and 6.8 t of CO 2 on a per vehicle basis. Similarly, for the future vehicles, using the Canadian electricity mix will lower the total carbon dioxide emissions by 21.15 t and the energy consumed is reduced by 218.49 GJ on a per capita basis and 26.53 GJ of energy and 7.22 t of CO 2 on a per vehicle basis. The well-to-tank efficiencies are higher with the Canadian electricity mix.

AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XI, PART I--MAINTAINING THE FUEL SYSTEM (PART I), CUMMINS DIESEL ENGINES, PART II--UNIT REPLACEMENT (ENGINE).

ERIC Educational Resources Information Center

Human Engineering Inst., Cleveland, OH.

THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF DIFFERENCES BETWEEN TWO AND FOUR CYCLE ENGINES, THE OPERATION AND MAINTENANCE OF THE DIESEL ENGINE FUEL SYSTEM, AND THE PROCEDURES FOR DIESEL ENGINE REMOVAL. TOPICS ARE (1) REVIEW OF TWO CYCLE AND FOUR CYCLE CONCEPT, (2) SOME BASIC CHARACTERISTICS OF FOUR CYCLE ENGINES,…

Evolution of engine cycles for STOVL propulsion concepts

NASA Technical Reports Server (NTRS)

Bucknell, R. L.; Frazier, R. H.; Giulianetti, D. J.

1990-01-01

Short Take-off, Vertical Landing (STOVL) demonstrator concepts using a common ATF engine core are discussed. These concepts include a separate fan and core flow engine cycle, mixed flow STOVL cycles, separate flow cycles convertible to mixed flow, and reaction control system engine air bleed. STOVL propulsion controls are discussed.

7 CFR 3201.25 - 2-Cycle engine oils.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 15 2012-01-01 2012-01-01 false 2-Cycle engine oils. 3201.25 Section 3201.25... Designated Items § 3201.25 2-Cycle engine oils. (a) Definition. Lubricants designed for use in 2-cycle engines to provide lubrication, decreased spark plug fouling, reduced deposit formation, and/or reduced...

7 CFR 3201.25 - 2-Cycle engine oils.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 15 2013-01-01 2013-01-01 false 2-Cycle engine oils. 3201.25 Section 3201.25... Designated Items § 3201.25 2-Cycle engine oils. (a) Definition. Lubricants designed for use in 2-cycle engines to provide lubrication, decreased spark plug fouling, reduced deposit formation, and/or reduced...

7 CFR 3201.25 - 2-Cycle engine oils.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 15 2014-01-01 2014-01-01 false 2-Cycle engine oils. 3201.25 Section 3201.25... Designated Items § 3201.25 2-Cycle engine oils. (a) Definition. Lubricants designed for use in 2-cycle engines to provide lubrication, decreased spark plug fouling, reduced deposit formation, and/or reduced...

HEAVY-DUTY TRUCK TEST CYCLES: COMBINING DRIVEABILITY WITH REALISTIC ENGINE EXERCISE

EPA Science Inventory

Heavy-duty engine certification testing uses a cycle that is scaled to the capabilities of each engine. As such, every engine should be equally challenged by the cycle's power demands. It would seem that a chassis cycle, similarly scaled to the capabilities of each vehicle, could...

Linking biogeomorphic feedbacks from ecosystem engineer to landscape scale: a panarchy approach

NASA Astrophysics Data System (ADS)

Eichel, Jana

2017-04-01

Scale is a fundamental concept in both ecology and geomorphology. Therefore, scale-based approaches are a valuable tool to bridge the disciplines and improve the understanding of feedbacks between geomorphic processes, landforms, material and organisms and ecological processes in biogeomorphology. Yet, linkages between biogeomorphic feedbacks on different scales, e.g. between ecosystem engineering and landscape scale patterns and dynamics, are not well understood. A panarchy approach sensu Holling et al. (2002) can help to close this research gap and explain how structure and function are created in biogeomorphic ecosystems. Based on results from previous biogeomorphic research in Turtmann glacier foreland (Switzerland; Eichel, 2017; Eichel et al. 2013, 2016), a panarchy concept is presented for lateral moraine slope biogeomorphic ecosystems. It depicts biogeomorphic feedbacks on different spatiotemporal scales as a set of nested adaptive cycles and links them by 'remember' and 'revolt' connections. On a small scale (cm2 - m2; seconds to years), the life cycle of the ecosystem engineer Dryas octopetala L. is considered as an adaptive cycle. Biogeomorphic succession within patches created by geomorphic processes represents an intermediate scale adaptive cycle (m2 - ha, years to decades), while geomorphic and ecologic pattern development at a landscape scale (ha - km2, decades to centuries) can be illustrated by an adaptive cycle of ‚biogeomorphic patch dynamics' (Eichel, 2017). In the panarchy, revolt connections link the smaller scale adaptive cycles to larger scale cycles: on lateral moraine slopes, the development of ecosystem engineer biomass and cover controls the engineering threshold of the biogeomorphic feedback window (Eichel et al., 2016) and therefore the onset of the biogeomorphic phase during biogeomorphic succession. In this phase, engineer patches and biogeomorphic structures can be created in the patch mosaic of the landscape. Remember connections link larger scale adaptive cycles to smaller scale cycles: configuration and properties of the lateral moraine slope patch mosaic control patch recolonization during biogeomorphic succession, while the patch-internal disturbance regime determines when the engineer can establish (establishment threshold of the biogeomorphic feedback window). Jointly, biogeomorphic feedback adaptive cycles and their connections in the panarchy create structure and function in the lateral moraine slope biogeomorphic ecosystem. Thus, by linking feedbacks on different spatiotemporal scales in biogeomorphic ecosystems and explaining the creation of ecosystem structure and function, the panarchy concept represents a useful tool for future biogeomorphic research. Eichel, J. 2017. Biogeomorphic dynamics in the Turtmann glacier forefield, Switzerland. PhD thesis, University of Bonn. Eichel J, Corenblit D, Dikau R. 2016. Conditions for feedbacks between geomorphic and vegetation dynamics on lateral moraine slopes: a biogeomorphic feedback window. Earth Surface Processes and Landforms 41: 406-419. DOI: 10.1002/esp.3859 Eichel J, Krautblatter M, Schmidtlein S, Dikau R. 2013. Biogeomorphic interactions in the Turtmann glacier forefield, Switzerland. Geomorphology 201 : 98-110. DOI: 10.1016/j.geomorph.2013.06.012 Holling CS, Gunderson LH, Peterson GD. 2002. Sustainability and Panarchies. In Panarchy: Understanding Transformations in Human and Natural Systems , . Island Press: Washington, D.C.; 63-102.

OAO-3 end of mission tests report

NASA Technical Reports Server (NTRS)

Kalil, F.; Kull, F. J.; Mcintosh, R.; Ollendorf, S.; Margolies, D. L.; Gemmell, J.; Tasevoli, C. M.; Polidan, R. S.; Kochevar, H.; Chapman, C.

1981-01-01

Twelve engineering type tests were performed on several subsystems and experiment(s) of the OAO 3 spacecraft near its end of mission. The systems tested include: Princeton experiment package (PEP), fine error system guidance, inertial reference unit, star trackers, heat pipes, thermal control coatings, command and data handling, solar array; batteries, and onboard processor/power boost regulator. Generally, the systems performed well for the 8 1/2 years life of OAO 3, although some degradation was noted in the sensitivity of PEP and in the absorptivity of the skin coatings. Battery life was prolonged during the life of the mission in large part by carefully monitoring the charge-discharge cycle with careful attention not to overcharge.

Innovative Adaptive Control Method Demonstrated for Active Suppression of Instabilities in Engine Combustors

NASA Technical Reports Server (NTRS)

Kopasakis, George

2005-01-01

This year, an improved adaptive-feedback control method was demonstrated that suppresses thermoacoustic instabilities in a liquid-fueled combustor of a type used in aircraft engines. Extensive research has been done to develop lean-burning (low fuel-to-air ratio) combustors that can reduce emissions throughout the mission cycle to reduce the environmental impact of aerospace propulsion systems. However, these lean-burning combustors are susceptible to thermoacoustic instabilities (high-frequency pressure waves), which can fatigue combustor components and even downstream turbine blades. This can significantly decrease the safe operating life of the combustor and turbine. Thus, suppressing the thermoacoustic combustor instabilities is an enabling technology for meeting the low-emission goals of the NASA Ultra-Efficient Engine Technology (UEET) Project.

Assessment of crack growth in a space shuttle main engine first-stage, high-pressure fuel turbopump blade

NASA Technical Reports Server (NTRS)

Abdul-Aziz, Ali

1993-01-01

A two-dimensional finite element fracture mechanics analysis of a space shuttle main engine (SSME) turbine blade firtree was performed using the MARC finite element code. The analysis was conducted under combined effects of thermal and mechanical loads at steady-state conditions. Data from a typical engine stand cycle of the SSME were used to run a heat transfer analysis and, subsequently, a thermal structural fracture mechanics analysis. Temperature and stress contours for the firtree under these operating conditions were generated. High stresses were found at the firtree lobes where crack initiation was triggered. A life assessment of the firtree was done by assuming an initial and a final crack size.

Cell-free synthetic biology for in vitro prototype engineering.

PubMed

Moore, Simon J; MacDonald, James T; Freemont, Paul S

2017-06-15

Cell-free transcription-translation is an expanding field in synthetic biology as a rapid prototyping platform for blueprinting the design of synthetic biological devices. Exemplar efforts include translation of prototype designs into medical test kits for on-site identification of viruses (Zika and Ebola), while gene circuit cascades can be tested, debugged and re-designed within rapid turnover times. Coupled with mathematical modelling, this discipline lends itself towards the precision engineering of new synthetic life. The next stages of cell-free look set to unlock new microbial hosts that remain slow to engineer and unsuited to rapid iterative design cycles. It is hoped that the development of such systems will provide new tools to aid the transition from cell-free prototype designs to functioning synthetic genetic circuits and engineered natural product pathways in living cells. © 2017 The Author(s).

Cell-free synthetic biology for in vitro prototype engineering

PubMed Central

Moore, Simon J.; MacDonald, James T.

2017-01-01

Cell-free transcription–translation is an expanding field in synthetic biology as a rapid prototyping platform for blueprinting the design of synthetic biological devices. Exemplar efforts include translation of prototype designs into medical test kits for on-site identification of viruses (Zika and Ebola), while gene circuit cascades can be tested, debugged and re-designed within rapid turnover times. Coupled with mathematical modelling, this discipline lends itself towards the precision engineering of new synthetic life. The next stages of cell-free look set to unlock new microbial hosts that remain slow to engineer and unsuited to rapid iterative design cycles. It is hoped that the development of such systems will provide new tools to aid the transition from cell-free prototype designs to functioning synthetic genetic circuits and engineered natural product pathways in living cells. PMID:28620040

Small Engine Component Technology (SECT) study

NASA Technical Reports Server (NTRS)

Larkin, T. R.

1986-01-01

The objective of this study is to identify high payoff technologies for year 2000 small gas turbine engines, and to provide a technology plan to guide research and technology efforts toward revolutionizing the small gas turbine technology base. The goal is to define the required technology to provide a 30 percent reduction in mission fuel burned, to reduce direct operating costs by at least 10 percent, and to provide increased reliability and durability of the gas turbine propulsion system. The baseline established to evaluate the year 2000 technology base was an 8-passenger commercial tilt-rotor aircraft powered by a current technology gas turbine engine. Three basic engine cycles were studied: the simple cycle engine, a waste heat recovery cycle, and a wave rotor engine cycle. For the simple cycle engine, two general arrangements were considered: the traditional concentric spool arrangement and a nonconcentric spool arrangement. Both a regenerative and a recuperative cycle were studied for the waste heat recovery cycle.

40 CFR 86.336-79 - Diesel engine test cycle.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Diesel engine test cycle. 86.336-79... New Gasoline-Fueled and Diesel-Fueled Heavy-Duty Engines; Gaseous Exhaust Test Procedures § 86.336-79 Diesel engine test cycle. (a) The following 13-mode cycle shall be followed in dynamometer operation...

40 CFR 86.1309-90 - Exhaust gas sampling system; Otto-cycle and non-petroleum-fueled engines.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-cycle and non-petroleum-fueled engines. 86.1309-90 Section 86.1309-90 Protection of Environment... HIGHWAY VEHICLES AND ENGINES (CONTINUED) Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty...-cycle and non-petroleum-fueled engines. (a)(1) General. The exhaust gas sampling system described in...

40 CFR 89.410 - Engine test cycle.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine test cycle. 89.410 Section 89...) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Exhaust Emission Test Procedures § 89.410 Engine test cycle. (a) Emissions shall be measured using one of the test cycles specified...

40 CFR 89.410 - Engine test cycle.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Engine test cycle. 89.410 Section 89...) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Exhaust Emission Test Procedures § 89.410 Engine test cycle. (a) Emissions shall be measured using one of the test cycles specified...

40 CFR 89.410 - Engine test cycle.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Engine test cycle. 89.410 Section 89...) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Exhaust Emission Test Procedures § 89.410 Engine test cycle. (a) Emissions shall be measured using one of the test cycles specified...

Systems Engineering and Integration for Advanced Life Support System and HST

NASA Technical Reports Server (NTRS)

Kamarani, Ali K.

2005-01-01

Systems engineering (SE) discipline has revolutionized the way engineers and managers think about solving issues related to design of complex systems: With continued development of state-of-the-art technologies, systems are becoming more complex and therefore, a systematic approach is essential to control and manage their integrated design and development. This complexity is driven from integration issues. In this case, subsystems must interact with one another in order to achieve integration objectives, and also achieve the overall system's required performance. Systems engineering process addresses these issues at multiple levels. It is a technology and management process dedicated to controlling all aspects of system life cycle to assure integration at all levels. The Advanced Integration Matrix (AIM) project serves as the systems engineering and integration function for the Human Support Technology (HST) program. AIM provides means for integrated test facilities and personnel for performance trade studies, analyses, integrated models, test results, and validated requirements of the integration of HST. The goal of AIM is to address systems-level integration issues for exploration missions. It will use an incremental systems integration approach to yield technologies, baselines for further development, and possible breakthrough concepts in the areas of technological and organizational interfaces, total information flow, system wide controls, technical synergism, mission operations protocols and procedures, and human-machine interfaces.

Low Thrust, Deep Throttling, US/CIS Integrated NTRE

NASA Astrophysics Data System (ADS)

Culver, Donald W.; Kolganov, Vyacheslav; Rochow, Richard F.

1994-07-01

In 1993 our international team performed a follow-on ``Nuclear Thermal Rocket Engine (NTRE) Extended Life Feasibility Assessment'' study for the Nuclear Propulsion Office (NPO) at NASAs Lewis Research Center. The main purpose of this study was to complete the 1992 study matrix to assess NTRE designs at thrust levels of 22.5, 11.3, and 6.8 tonnes, using Commonwealth of Independent States (CIS) reactor technology. An additional Aerojet goal was to continue improving the NTRE concept we had generated. Deep throttling, mission performance optimized engine design parametrics, and reliability/cost enhancing engine system simplifications were studied, because they seem to be the last three basic design improvements sorely needed by post-NERVA NTRE. Deep throttling improves engine life by eliminating damaging thermal and mechanical shocks caused by after-cooling with pulsed coolant flow. Alternately, it improves mission performance with steady flow after-cooling by minimizing reactor over-cooling. Deep throttling also provides a practical transition from high pressures and powers of the high thrust power cycle to the low pressures and powers of our electric power generating mode. Two deep throttling designs are discussed; a workable system that was studied and a simplified system that is recommended for future study. Mission-optimized engine thrust/weight (T/W) and Isp predictions are included along with system flow schemes and concept sketches.

Solar powered Stirling cycle electrical generator

NASA Technical Reports Server (NTRS)

Shaltens, Richard K.

1991-01-01

Under NASA's Civil Space Technology Initiative (CSTI), the NASA Lewis Research Center is developing the technology needed for free-piston Stirling engines as a candidate power source for space systems in the late 1990's and into the next century. Space power requirements include high efficiency, very long life, high reliability, and low vibration. Furthermore, system weight and operating temperature are important. The free-piston Stirling engine has the potential for a highly reliable engine with long life because it has only a few moving parts, non-contacting gas bearings, and can be hermetically sealed. These attributes of the free-piston Stirling engine also make it a viable candidate for terrestrial applications. In cooperation with the Department of Energy, system designs are currently being completed that feature the free-piston Stirling engine for terrestrial applications. Industry teams were assembled and are currently completing designs for two Advanced Stirling Conversion Systems utilizing technology being developed under the NASA CSTI Program. These systems, when coupled with a parabolic mirror to collect the solar energy, are capable of producing about 25 kW of electricity to a utility grid. Industry has identified a niche market for dish Stirling systems for worldwide remote power application. They believe that these niche markets may play a major role in the introduction of Stirling products into the commercial market.

The effect of porosity and gamma-gamma' eutectic content on the low cycle fatigue behavior of hydrogen-charged PWA-1480

NASA Technical Reports Server (NTRS)

Gayda, John; Dreshfield, Robert L.; Gabb, Timothy P.

1991-01-01

Single crystal superalloys such as PWA 1480 are considered for turbopump blades in the main engines of the space shuttle. As fatigue resistance in a hydrogen environment is a key issue in this application, a study of the effect of porosity and gamma-gamma' eutectic content on the fatigue life of a hydrogen-charged PWA 1480 was performed. Porosity and eutectic were linked to fatigue initiation, and therefore reduction of either of both may be one means to improve fatigue life of PWA 1480 when hydrogen is present.

Long life Regenerative Fuel Cell technology development plan

NASA Technical Reports Server (NTRS)

Littman, Franklin D.; Cataldo, Robert L.; Mcelroy, James F.; Stedman, Jay K.

1992-01-01

This paper summarizes a technology roadmap for completing advanced development of a Proton Exchange Membrane (PEM) Regenerative Fuel Cell (RFC) to meet long life (20,000 hrs at 50 percent duty cycle) mobile or portable power system applications on the surface of the moon and Mars. Development of two different sized RFC power system modules is included in this plan (3 and 7.5 kWe). A conservative approach was taken which includes the development of a Ground Engineering System, Qualification Unit, and Flight Unit. This paper includes a concept description, technology assessment, development issues, development tasks, and development schedule.

Need for Cost Optimization of Space Life Support Systems

NASA Technical Reports Server (NTRS)

Jones, Harry W.; Anderson, Grant

2017-01-01

As the nation plans manned missions that go far beyond Earth orbit to Mars, there is an urgent need for a robust, disciplined systems engineering methodology that can identify an optimized Environmental Control and Life Support (ECLSS) architecture for long duration deep space missions. But unlike the previously used Equivalent System Mass (ESM), the method must be inclusive of all driving parameters and emphasize the economic analysis of life support system design. The key parameter for this analysis is Life Cycle Cost (LCC). LCC takes into account the cost for development and qualification of the system, launch costs, operational costs, maintenance costs and all other relevant and associated costs. Additionally, an effective methodology must consider system technical performance, safety, reliability, maintainability, crew time, and other factors that could affect the overall merit of the life support system.

Programming support environment issues in the Byron programming environment

NASA Technical Reports Server (NTRS)

Larsen, Matthew J.

1986-01-01

Issues are discussed which programming support environments need to address in order to successfully support software engineering. These concerns are divided into two categories. The first category, issues of how software development is supported by an environment, includes support of the full life cycle, methodology flexibility, and support of software reusability. The second category contains issues of how environments should operate, such as tool reusability and integration, user friendliness, networking, and use of a central data base. This discussion is followed by an examination of Byron, an Ada based programming support environment developed at Intermetrics, focusing on the solutions Byron offers to these problems, including the support provided for software reusability and the test and maintenance phases of the life cycle. The use of Byron in project development is described briefly, and some suggestions for future Byron tools and user written tools are presented.

RT-Syn: A real-time software system generator

NASA Technical Reports Server (NTRS)

Setliff, Dorothy E.

1992-01-01

This paper presents research into providing highly reusable and maintainable components by using automatic software synthesis techniques. This proposal uses domain knowledge combined with automatic software synthesis techniques to engineer large-scale mission-critical real-time software. The hypothesis centers on a software synthesis architecture that specifically incorporates application-specific (in this case real-time) knowledge. This architecture synthesizes complex system software to meet a behavioral specification and external interaction design constraints. Some examples of these external constraints are communication protocols, precisions, timing, and space limitations. The incorporation of application-specific knowledge facilitates the generation of mathematical software metrics which are used to narrow the design space, thereby making software synthesis tractable. Success has the potential to dramatically reduce mission-critical system life-cycle costs not only by reducing development time, but more importantly facilitating maintenance, modifications, and extensions of complex mission-critical software systems, which are currently dominating life cycle costs.

Sampling and monitoring for closure

USGS Publications Warehouse

McLemore, V.T.; Russell, C.C.; Smith, K.S.

2004-01-01

The Metals Mining Sector of the Acid Drainage Technology Initiative (ADTI-MMS) addresses technical drainage-quality issues related to metal mining and related metallurgical operations, for future and active mines, as well as, for historical mines and mining districts. One of the first projects of ADTI-MMS is to develop a handbook describing the best sampling, monitoring, predicting, mitigating, and modeling of drainage from metal mines, pit lakes and related metallurgical facilities based upon current scientific and engineering practices. One of the important aspects of planning a new mine in today's regulatory environment is the philosophy of designing a new or existing mine or expansion of operations for ultimate closure. The holistic philosophy taken in the ADTI-MMS handbook maintains that sampling and monitoring programs should be designed to take into account all aspects of the mine-life cycle. Data required for the closure of the operation are obtained throughout the mine-life cycle, from exploration through post-closure.

[The sanitary and hygienic state of solid garbage burial grounds in the stages of a life cycle].

PubMed

Zomarev, A M; Vaĭsman, Ia I; Zaĭtseva, T A; Glushankova, I S

2010-01-01

The purpose of the study was to assess the sanitary-and-hygienic state of solid garbage (SG) burial grounds in the Perm Territory in different stage of a life cycle. This paper presents the results of the study of deposited waste, forming dump soil, and SG ground emissions by general sanitary and sanitary-microbiological parameters and their effect on environmental objects. The performed studies of the sanitary-and-hygienic situation on some grounds of the Perm Territory suggest that there is a need for setting up a system for sanitary-and-monitoring of SG ground and for elaborating engineering, organizational, and prophylactic measures to assure the sanitary-and-hygienic safety of objects and to control the quality and quantity of waste to be buried and the currents of emissions (ground body degassing, filtrating sewage drainage and purification).

Artificial Intelligence Software Engineering (AISE) model

NASA Technical Reports Server (NTRS)

Kiss, Peter A.

1990-01-01

The American Institute of Aeronautics and Astronautics has initiated a committee on standards for Artificial Intelligence. Presented are the initial efforts of one of the working groups of that committee. A candidate model is presented for the development life cycle of knowledge based systems (KBSs). The intent is for the model to be used by the aerospace community and eventually be evolved into a standard. The model is rooted in the evolutionary model, borrows from the spiral model, and is embedded in the standard Waterfall model for software development. Its intent is to satisfy the development of both stand-alone and embedded KBSs. The phases of the life cycle are shown and detailed as are the review points that constitute the key milestones throughout the development process. The applicability and strengths of the model are discussed along with areas needing further development and refinement by the aerospace community.

Advanced supersonic propulsion system technology study, phase 2

NASA Technical Reports Server (NTRS)

Allan, R. D.

1975-01-01

Variable cycle engines were identified, based on the mixed-flow low-bypass-ratio augmented turbofan cycle, which has shown excellent range capability in the AST airplane. The best mixed-flow augmented turbofan engine was selected based on range in the AST Baseline Airplane. Selected variable cycle engine features were added to this best conventional baseline engine, and the Dual-Cycle VCE and Double-Bypass VCE were defined. The conventional mixed-flow turbofan and the Double-Bypass VCE were on the subjects of engine preliminary design studies to determine mechanical feasibility, confirm weight and dimensional estimates, and identify the necessary technology considered not yet available. Critical engine components were studied and incorporated into the variable cycle engine design.

Development of engine activity cycles for the prime movers of unconventional natural gas well development.

PubMed

Johnson, Derek; Heltzel, Robert; Nix, Andrew; Barrow, Rebekah

2017-03-01

With the advent of unconventional natural gas resources, new research focuses on the efficiency and emissions of the prime movers powering these fleets. These prime movers also play important roles in emissions inventories for this sector. Industry seeks to reduce operating costs by decreasing the required fuel demands of these high horsepower engines but conducting in-field or full-scale research on new technologies is cost prohibitive. As such, this research completed extensive in-use data collection efforts for the engines powering over-the-road trucks, drilling engines, and hydraulic stimulation pump engines. These engine activity data were processed in order to make representative test cycles using a Markov Chain, Monte Carlo (MCMC) simulation method. Such cycles can be applied under controlled environments on scaled engines for future research. In addition to MCMC, genetic algorithms were used to improve the overall performance values for the test cycles and smoothing was applied to ensure regression criteria were met during implementation on a test engine and dynamometer. The variations in cycle and in-use statistics are presented along with comparisons to conventional test cycles used for emissions compliance. Development of representative, engine dynamometer test cycles, from in-use activity data, is crucial in understanding fuel efficiency and emissions for engine operating modes that are different from cycles mandated by the Code of Federal Regulations. Representative cycles were created for the prime movers of unconventional well development-over-the-road (OTR) trucks and drilling and hydraulic fracturing engines. The representative cycles are implemented on scaled engines to reduce fuel consumption during research and development of new technologies in controlled laboratory environments.

The History and Promise of Combined Cycle Engines for Access to Space Applications

NASA Technical Reports Server (NTRS)

Clark, Casie

2010-01-01

For the summer of 2010, I have been working in the Aerodynamics and Propulsion Branch at NASA Dryden Flight Research Center studying combined-cycle engines, a high speed propulsion concept. Combined cycle engines integrate multiple propulsion systems into a single engine capable of running in multiple modes. These different modes allow the engine to be extremely versatile and efficient in varied flight conditions. The two most common types of combined cycle engines are Rocket-Based Combined Cycle (RBCC) and Turbine Based Combined Cycle (TBCC). The RBCC essentially combines a rocket and ramjet engine, while the TBCC integrates a turbojet and ramjet1. These two engines are able to switch between different propulsion modes to achieve maximum performance. Extensive conceptual and ground test studies of RBCC engines have been undertaken; however, an RBCC engine has never, to my knowledge, been demonstrated in flight. RBCC engines are of particular interest because they could potentially power a reusable launch vehicle (RLV) into space. The TBCC has been flight tested and shown to be effective at reaching supersonic speeds, most notably in the SR-71 Blackbird2.

Origin of life: hypothesized roles of high-energy electrical discharges, infrared radiation, thermosynthesis and pre-photosynthesis.

PubMed

Trevors, J T

2012-12-01

The hypothesis is proposed that during the organization of pre-biotic bacterial cell(s), high-energy electrical discharges, infrared radiation (IR), thermosynthesis and possibly pre-photosynthesis were central to the origin of life. High-energy electrical discharges generated some simple organic molecules available for the origin of life. Infrared radiation, both incoming to the Earth and generated on the cooling Earth with day/night and warming/cooling cycles, was a component of heat engine thermosynthesis before enzymes and the genetic code were present. Eventually, a primitive forerunner of photosynthesis and the capability to capture visible light emerged. In addition, the dual particle-wave nature of light is discussed from the perspective that life requires light acting both as a wave and particle.

Life Cycle Assessment of Vehicle Lightweighting: A Physics-Based Model To Estimate Use-Phase Fuel Consumption of Electrified Vehicles

DOE PAGES

Kim, Hyung Chul; Wallington, Timothy J.

2016-08-17

Assessing the life-cycle benefits of vehicle lightweighting requires a quantitative description of mass-induced fuel consumption (MIF) and fuel reduction values (FRVs). We have extended our physics-based model of MIF and FRVs for internal combustion engine vehicles (ICEVs) to electrified vehicles (EVs) including hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs). We illustrate the utility of the model by calculating MIFs and FRVs for 37 EVs and 13 ICEVs. BEVs have much smaller MIF and FRVs, both in the range 0.04-0.07 L e/(100 km 100 kg), than those for ICEVs which are in the rangesmore » 0.19-0.32 and 0.16-0.22 L/(100 km 100 kg), respectively. The MIF and FRVs for HEVs and PHEVs mostly lie between those for ICEVs and BEVs. Powertrain resizing increases the FRVs for ICEVs, HEVs and PHEVs. Lightweighting EVs is less effective in reducing greenhouse gas emissions than lightweighting ICEVs, however the benefits differ substantially for different vehicle models. The physics-based approach outlined here enables model specific assessments for ICEVs, HEVs, PHEVs, and BEVs required to determine the optimal strategy for maximizing the life-cycle benefits of lightweighting the light-duty vehicle fleet.« less

Life Cycle Assessment of Vehicle Lightweighting: A Physics-Based Model To Estimate Use-Phase Fuel Consumption of Electrified Vehicles.

PubMed

Kim, Hyung Chul; Wallington, Timothy J

2016-10-18

Assessing the life-cycle benefits of vehicle lightweighting requires a quantitative description of mass-induced fuel consumption (MIF) and fuel reduction values (FRVs). We have extended our physics-based model of MIF and FRVs for internal combustion engine vehicles (ICEVs) to electrified vehicles (EVs) including hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs). We illustrate the utility of the model by calculating MIFs and FRVs for 37 EVs and 13 ICEVs. BEVs have much smaller MIF and FRVs, both in the range 0.04-0.07 L e /(100 km 100 kg), than those for ICEVs which are in the ranges 0.19-0.32 and 0.16-0.22 L/(100 km 100 kg), respectively. The MIF and FRVs for HEVs and PHEVs mostly lie between those for ICEVs and BEVs. Powertrain resizing increases the FRVs for ICEVs, HEVs and PHEVs. Lightweighting EVs is less effective in reducing greenhouse gas emissions than lightweighting ICEVs, however the benefits differ substantially for different vehicle models. The physics-based approach outlined here enables model specific assessments for ICEVs, HEVs, PHEVs, and BEVs required to determine the optimal strategy for maximizing the life-cycle benefits of lightweighting the light-duty vehicle fleet.

Fuel economy and life-cycle cost analysis of a fuel cell hybrid vehicle

NASA Astrophysics Data System (ADS)

Jeong, Kwi Seong; Oh, Byeong Soo

The most promising vehicle engine that can overcome the problem of present internal combustion is the hydrogen fuel cell. Fuel cells are devices that change chemical energy directly into electrical energy without combustion. Pure fuel cell vehicles and fuel cell hybrid vehicles (i.e. a combination of fuel cell and battery) as energy sources are studied. Considerations of efficiency, fuel economy, and the characteristics of power output in hybridization of fuel cell vehicle are necessary. In the case of Federal Urban Driving Schedule (FUDS) cycle simulation, hybridization is more efficient than a pure fuel cell vehicle. The reason is that it is possible to capture regenerative braking energy and to operate the fuel cell system within a more efficient range by using battery. Life-cycle cost is largely affected by the fuel cell size, fuel cell cost, and hydrogen cost. When the cost of fuel cell is high, hybridization is profitable, but when the cost of fuel cell is less than 400 US$/kW, a pure fuel cell vehicle is more profitable.

7 CFR 2902.25 - 2-Cycle engine oils.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 15 2011-01-01 2011-01-01 false 2-Cycle engine oils. 2902.25 Section 2902.25... Items § 2902.25 2-Cycle engine oils. (a) Definition. Lubricants designed for use in 2-cycle engines to... least 34 percent, which shall be based on the amount of qualifying biobased carbon in the product as a...

40 CFR 90.410 - Engine test cycle.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Engine test cycle. 90.410 Section 90...) CONTROL OF EMISSIONS FROM NONROAD SPARK-IGNITION ENGINES AT OR BELOW 19 KILOWATTS Gaseous Exhaust Test Procedures § 90.410 Engine test cycle. (a) Follow the appropriate 6-mode test cycle for Class I, I-B and II...

40 CFR 90.410 - Engine test cycle.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine test cycle. 90.410 Section 90...) CONTROL OF EMISSIONS FROM NONROAD SPARK-IGNITION ENGINES AT OR BELOW 19 KILOWATTS Gaseous Exhaust Test Procedures § 90.410 Engine test cycle. (a) Follow the appropriate 6-mode test cycle for Class I, I-B and II...

High-temperature low cycle fatigue behavior of a gray cast iron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fan, K.L., E-mail: 12klfan@tongji.edu.cn; He, G.Q.; She, M.

The strain controlled low cycle fatigue properties of the studied gray cast iron for engine cylinder blocks were investigated. At the same total strain amplitude, the low cycle fatigue life of the studied material at 523 K was higher than that at 423 K. The fatigue behavior of the studied material was characterized as cyclic softening at any given total strain amplitude (0.12%–0.24%), which was attributed to fatigue crack initiation and propagation. Moreover, this material exhibited asymmetric hysteresis loops due to the presence of the graphite lamellas. Transmission electron microscopy analysis suggested that cyclic softening was also caused by themore » interactions of dislocations at 423 K, such as cell structure in ferrite, whereas cyclic softening was related to subgrain boundaries and dislocation climbing at 523 K. Micro-analysis of specimen fracture appearance was conducted in order to obtain the fracture characteristics and crack paths for different strain amplitudes. It showed that the higher the temperature, the rougher the crack face of the examined gray cast iron at the same total strain amplitude. Additionally, the microcracks were readily blunted during growth inside the pearlite matrix at 423 K, whereas the microcracks could easily pass through pearlite matrix along with deflection at 523 K. The results of fatigue experiments consistently showed that fatigue damage for the studied material at 423 K was lower than that at 523 K under any given total strain amplitude. - Highlights: • The low cycle fatigue behavior of the HT250 for engine cylinder blocks was investigated. • TEM investigations were conducted to explain the cyclic deformation response. • The low cycle fatigue cracks of HT250 GCI were studied by SEM. • The fatigue life of the examined material at 523 K is higher than that at 423 K.« less

Creating system engineering products with executable models in a model-based engineering environment

NASA Astrophysics Data System (ADS)

Karban, Robert; Dekens, Frank G.; Herzig, Sebastian; Elaasar, Maged; Jankevičius, Nerijus

2016-08-01

Applying systems engineering across the life-cycle results in a number of products built from interdependent sources of information using different kinds of system level analysis. This paper focuses on leveraging the Executable System Engineering Method (ESEM) [1] [2], which automates requirements verification (e.g. power and mass budget margins and duration analysis of operational modes) using executable SysML [3] models. The particular value proposition is to integrate requirements, and executable behavior and performance models for certain types of system level analysis. The models are created with modeling patterns that involve structural, behavioral and parametric diagrams, and are managed by an open source Model Based Engineering Environment (named OpenMBEE [4]). This paper demonstrates how the ESEM is applied in conjunction with OpenMBEE to create key engineering products (e.g. operational concept document) for the Alignment and Phasing System (APS) within the Thirty Meter Telescope (TMT) project [5], which is under development by the TMT International Observatory (TIO) [5].

High temperature dynamic engine seal technology development

NASA Technical Reports Server (NTRS)

Steinetz, Bruce M.; Dellacorte, Christopher; Machinchick, Michael; Mutharasan, Rajakkannu; Du, Guang-Wu; Ko, Frank; Sirocky, Paul J.; Miller, Jeffrey H.

1992-01-01

Combined cycle ramjet/scramjet engines being designed for advanced hypersonic vehicles, including the National Aerospace Plane (NASP), require innovative high temperature dynamic seals to seal the sliding interfaces of the articulated engine panels. New seals are required that will operate hot (1200 to 2000 F), seal pressures ranging from 0 to 100 psi, remain flexible to accommodate significant sidewall distortions, and resist abrasion over the engine's operational life. This report reviews the recent high temperature durability screening assessments of a new braided rope seal concept, braided of emerging high temperature materials, that shows promise of meeting many of the seal demands of hypersonic engines. The paper presents durability data for: (1) the fundamental seal building blocks, a range of candidate ceramic fiber tows; and for (2) braided rope seal subelements scrubbed under engine simulated sliding, temperature, and preload conditions. Seal material/architecture attributes and limitations are identified through the investigations performed. The paper summarizes the current seal technology development status and presents areas in which future work will be performed.

Human Engineering Operations and Habitability Assessment: A Process for Advanced Life Support Ground Facility Testbeds

NASA Technical Reports Server (NTRS)

Connolly, Janis H.; Arch, M.; Elfezouaty, Eileen Schultz; Novak, Jennifer Blume; Bond, Robert L. (Technical Monitor)

1999-01-01

Design and Human Engineering (HE) processes strive to ensure that the human-machine interface is designed for optimal performance throughout the system life cycle. Each component can be tested and assessed independently to assure optimal performance, but it is not until full integration that the system and the inherent interactions between the system components can be assessed as a whole. HE processes (which are defining/app lying requirements for human interaction with missions/systems) are included in space flight activities, but also need to be included in ground activities and specifically, ground facility testbeds such as Bio-Plex. A unique aspect of the Bio-Plex Facility is the integral issue of Habitability which includes qualities of the environment that allow humans to work and live. HE is a process by which Habitability and system performance can be assessed.

Conceptual design study of an Improved Gas Turbine (IGT) powertrain

NASA Technical Reports Server (NTRS)

Johnson, R. A.

1979-01-01

Design concepts for an improved automotive gas turbine powertrain are discussed. Twenty percent fuel economy improvement (over 1976), competitive costs (initial and life cycle), high reliability/life, low emissions, and noise/safety compliance were among the factors considered. The powertrain selected consists of a two shaft gas turbine engine with variable geometry aerodynamic components and a single disk rotating regenerator. The regenerator disk, gasifier turbine rotor, and several hot section flowpath parts are ceramic. The powertrain utilizes a conventional automatic transmission. The closest competitor was a single shaft turbine engine matched to a continuously variable transmission (CVT). Both candidate powertrain systems were found to be similar in many respects; however, the CVT represented a significant increase in development cost, technical risk, and production start-up costs over the conventional automatic transmission. Installation of the gas turbine powertrain was investigated for a transverse mounted, front wheel drive vehicle.

Advanced Transportation System Studies. Technical Area 3: Alternate Propulsion Subsystem Concepts. Volume 1; Executive Summary

NASA Technical Reports Server (NTRS)

Levack, Daniel J. H.

2000-01-01

The Alternate Propulsion Subsystem Concepts contract had seven tasks defined that are reported under this contract deliverable. The tasks were: FAA Restart Study, J-2S Restart Study, Propulsion Database Development. SSME Upper Stage Use. CERs for Liquid Propellant Rocket Engines. Advanced Low Cost Engines, and Tripropellant Comparison Study. The two restart studies, F-1A and J-2S, generated program plans for restarting production of each engine. Special emphasis was placed on determining changes to individual parts due to obsolete materials, changes in OSHA and environmental concerns, new processes available, and any configuration changes to the engines. The Propulsion Database Development task developed a database structure and format which is easy to use and modify while also being comprehensive in the level of detail available. The database structure included extensive engine information and allows for parametric data generation for conceptual engine concepts. The SSME Upper Stage Use task examined the changes needed or desirable to use the SSME as an upper stage engine both in a second stage and in a translunar injection stage. The CERs for Liquid Engines task developed qualitative parametric cost estimating relationships at the engine and major subassembly level for estimating development and production costs of chemical propulsion liquid rocket engines. The Advanced Low Cost Engines task examined propulsion systems for SSTO applications including engine concept definition, mission analysis. trade studies. operating point selection, turbomachinery alternatives, life cycle cost, weight definition. and point design conceptual drawings and component design. The task concentrated on bipropellant engines, but also examined tripropellant engines. The Tripropellant Comparison Study task provided an unambiguous comparison among various tripropellant implementation approaches and cycle choices, and then compared them to similarly designed bipropellant engines in the SSTO mission This volume overviews each of the tasks giving its objectives, main results. and conclusions. More detailed Final Task Reports are available on each individual task.

75 FR 23572 - Airworthiness Directives; Airbus Model A300 B2-1C, B2-203, B2K-3C, B4-103, B4-203, B4-2C...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-04

... cycles 6,700 flight 80A3 or Pratt & Whitney engines. flight cycles \\1\\. flight cycles or \\2\\. cycles or...-200 airplanes with GE CF6- 18,000 total 19,500 total 250 flight cycles 5,800 flight 80C2 engines... flight cycles 6,700 flight Pratt & Whitney JT9D engines. flight cycles \\1\\. flight cycles or \\2\\. cycles...

Engineering Lessons Learned and Systems Engineering Applications

NASA Technical Reports Server (NTRS)

Gill, Paul S.; Garcia, Danny; Vaughan, William W.

2005-01-01

Systems Engineering is fundamental to good engineering, which in turn depends on the integration and application of engineering lessons learned and technical standards. Thus, good Systems Engineering also depends on systems engineering lessons learned from within the aerospace industry being documented and applied. About ten percent of the engineering lessons learned documented in the NASA Lessons Learned Information System are directly related to Systems Engineering. A key issue associated with lessons learned datasets is the communication and incorporation of this information into engineering processes. Systems Engineering has been defined (EINIS-632) as "an interdisciplinary approach encompassing the entire technical effort to evolve and verify an integrated and life-cycle balanced set of system people, product, and process solutions that satisfy customer needs". Designing reliable space-based systems has always been a goal for NASA, and many painful lessons have been learned along the way. One of the continuing functions of a system engineer is to compile development and operations "lessons learned" documents and ensure their integration into future systems development activities. They can produce insights and information for risk identification identification and characterization. on a new project. Lessons learned files from previous projects are especially valuable in risk

United States Air Force Summer Faculty Research Program for 1990. Program Management Report

DTIC Science & Technology

1991-06-05

propagation characteristics were extensively studied using pencil lead breaks in a center notch. For the fatigue studies center crack samples of 2024 - T351 ... aluminum specimens during fatigue cycling. The experimental procedure involved excitation of Rayleigh waves on the surface of each specimen and...Research Program (SFRP) provides opportunities for research in the physical sciences, engineering, and life sciences. The program has been effective

Green Chemistry and Engineering Opportunity Assessment (GC&EOA) to US Army. A Case Study in Sustainable Remediation

DTIC Science & Technology

2009-11-30

transport of airborne contaminants and dust o Use heavy equipment efficiently (e.g. diesel emission reduction plan) o Maximize use of machinery equipped...remediation) Design for Energy Efficiency Favor low-energy technologies ( bioremediation , phytoremediation) where possible and effective; Use...Selection of a Remediation Scenario for a Diesel - Contaminated Site Using LCA. International Journal of Life Cycle Assessment 12(4), 239-251

Design and Analysis of a Model Reconfigurable Cyber-Exercise Laboratory (RCEL) for Information Assurance Education

DTIC Science & Technology

2004-03-01

with MySQL . This choice was made because MySQL is open source. Any significant database engine such as Oracle or MS- SQL or even MS Access can be used...10 Figure 6. The DoD vs . Commercial Life Cycle...necessarily be interested in SCADA network security 13. MySQL (Database server) – This station represents a typical data server for a web page

Risk Management Considerations for Interoperable Acquisition

DTIC Science & Technology

2006-08-01

Electronics Engineers (IEEE) to harmonize the standards for software (IEEE 12207 ) and system (IEEE 15288) life-cycle processes. A goal of this harmonization...management ( ISO /IEC 16085) is being generalized to apply to the systems level. The revised, generalized standard will add require- ments and guidance for the...risk management. The documents include the following: • ISO /IEC Guide 73: Risk Management—Vocabulary—Guidelines for use in stan- dards [ ISO 02

Core Logistics Capability Policy Applied to USAF Combat Aircraft Avionics Software: A Systems Engineering Analysis

DTIC Science & Technology

2010-06-01

cannot make a distinction between software maintenance and development” (Sharma, 2004). ISO /IEC 12207 Software Lifecycle Processes offers a guide to...synopsis of ISO /IEC 12207 , Raghu Singh of the Federal Aviation Administration states “Whenever a software product needs modifications, the development...Corporation. Singh, R. (1998). International Standard ISO /IEC 12207 Software Life Cycle Processes. Washington: Federal Aviation Administration. The Joint

Integrated Instrumentation and Sensor Systems Enabling Condition-Based Maintenance of Aerospace Equipment

DTIC Science & Technology

2012-01-01

systems . For some specific sensor requirements in the domains considered here, for example, assessing system behavior and component state in gas turbine ...Cost Objectives. In general , the implication of the suitability and life cycle cost [LCC] driven objectives for integrated instrumentation/sensor system ...section should be considered. In general , the systems engineering approach provided clear benefits in defining user significant IISS system requirements and

Reuse-Driven Software Processes Guidebook. Version 02.00.03

DTIC Science & Technology

1993-11-01

a required sys - tem without unduly constraining the details of the solution. The Naval Research Laboratory Software Cost Reduction project developed...conventional manner. The emphasis is still on the development of "one-of-a-kind" sys - tems and the phased completion and review of corresponding...Application Engineering to improve the life-cycle productivity of Sy - 21 OVM ftrdauntals of Syatbes the total software development enterprise. The

Expedition 21 FE Thirsk installs the new CSI-03

NASA Image and Video Library

2009-11-18

ISS021-E-029873 (18 Nov. 2009) --- Canadian Space Agency astronaut Robert Thirsk, Expedition 21 flight engineer, works with the new Commercial Generic Bioprocessing Apparatus (CGBA) Science Insert 03 (CSI-03) assembly in the Kibo laboratory of the International Space Station. CSI-03 is flying two butterfly habitats during this mission and will examine the complete life cycle of the butterflies as they eat, grow and undergo metamorphosis in space.

Expedition 21 FE Thirsk installs the new CSI-03

NASA Image and Video Library

2009-11-18

ISS021-E-029871 (18 Nov. 2009) --- Canadian Space Agency astronaut Robert Thirsk, Expedition 21 flight engineer, works with the new Commercial Generic Bioprocessing Apparatus (CGBA) Science Insert 03 (CSI-03) assembly in the Kibo laboratory of the International Space Station. CSI-03 is flying two butterfly habitats during this mission and will examine the complete life cycle of the butterflies as they eat, grow and undergo metamorphosis in space.

CrossTalk: The Journal of Defense Software Engineering. Volume 21, Number 1

DTIC Science & Technology

2008-01-01

project manage- ment and the individual components of the software life-cycle model ; it will be awarded for...software professionals that had been formally educated in software project manage- ment. The study indicated that our industry is lacking in program managers...soft- ware developments get bigger, more complicated, and more dependent on senior software pro- fessionals to get the project on the right path

NASA Hazard Analysis Process

NASA Technical Reports Server (NTRS)

Deckert, George

2010-01-01

This viewgraph presentation reviews The NASA Hazard Analysis process. The contents include: 1) Significant Incidents and Close Calls in Human Spaceflight; 2) Subsystem Safety Engineering Through the Project Life Cycle; 3) The Risk Informed Design Process; 4) Types of NASA Hazard Analysis; 5) Preliminary Hazard Analysis (PHA); 6) Hazard Analysis Process; 7) Identify Hazardous Conditions; 8) Consider All Interfaces; 9) Work a Preliminary Hazard List; 10) NASA Generic Hazards List; and 11) Final Thoughts

Enabling Technologies for Unified Life-Cycle Engineering of Structural Components

DTIC Science & Technology

1991-03-22

representations for entities in the ULCE system for unambiguous, reliable, and efficient retrieval, manipulation, and transfer of data. Develop a rapid analysis...approaches to these functions. It is reasonable to assume that program budgets for future systems will be more restrictive and that fixed- price contracting...enemy threats, economics, and politics. The requirements are voluminous and may stipulate firm fixed- price proposals with detailed schedules. At this

Army Logistician. Volume 34, Issue 2, March-April 2002

DTIC Science & Technology

2002-04-01

potential coalition part- ners; and, • Leverage of U.S. resources through cost sharing and economies of scale.” DOD guidance focuses on the broad goals of...be funded privately through the Army Historical Foundation. • Operations research and operations management. • Engineering economy , life-cycle cost ...will be implemented this summer. A review of Army organizations below the headquarters level should be completed this spring. EDGEWOOD ENZYMATIC DECON