SEARCH · Engineering Papers

Results for “performance contracting”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

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

At least 991 records · Page 55

All sources NASA NTRS DOE OSTI

NASA NTRS2019

Correlation of Full-Scale Isolated Proprotor Performance and Loads

A full-scale isolated proprotor test is currently being conducted in the USAF National Full-Scale Aerodynamics Complex (NFAC) 40- by 80-Foot Wind Tunnel at NASA Ames. The test article is a 3-bladed research rotor derived from the right-hand rotor of the AW609; this rotor was manufactured by Bell Helicopter under contract to NASA. In this paper, this research rotor is referred to as "699". The test, nearly completed, is an integral part of the initial checkout test of the newly developed Tiltrotor Test Rig (TTR), whose purpose is to test advanced, full-scale proprotors in the NFAC. Figure 1 shows the TTR/699 installed in the 40- by 80-Foot test section. The TTR rotor axis is horizontal and the rig rotates in yaw on the wind tunnel turntable for conversion (transition) and helicopter mode testing. To date, a substantial amount of wind tunnel test data has already been acquired. The completed operational conditions include hover, airplane mode (cruise, wind tunnel airspeed V=61 to 267 knots), and the helicopter and conversion conditions (with a comprehensive sweep of the TTR yaw angle ranging, to date, from 90-deg yaw helicopter mode to 30-deg yaw conversion mode, at varying airspeeds). This 699 proprotor performance and loads correlation study uses these newly acquired wind tunnel test data. This paper represents the third analytical study, coming after two earlier analytical studies on the TTR/699; that is, a 2018 paper on pre-test predictions of 699 performance and loads, Ref. 1, and an upcoming January 2019 paper on aeroelastic stability analysis of the TTR/699 installed in the 40- by 80-Foot Wind Tunnel, Ref. 2. Reference 8 will present an overview of the entire TTR/699 test program. For completeness, Ref. 3 addresses the development and initial testing of the TTR. Background information on the TTR effort at NASA Ames can be found at the Aeromechanics website: https://rotorcraft.arc.nasa.gov/Research/Facilities/ttr.html. To the authors' knowledge, the full-scale results presented in this paper are the first of their kind. A literature survey brought up several existing correlation studies, but these were either based on small-scale test data (for example, the studies performed by the University of Maryland) or full-scale aircraft flight test data (for example, flight tests conducted by Bell Helicopter). Separately, the 2009 NASA study involving the JVX rotor is relevant (see Ref.4). The JVX is closely similar to the 699 in size and aerodynamics, and is accordingly a good reference for performance calculations. In Ref. 1 (as mentioned above), pre-test reality checks of the current analytical model were made by comparing JVX and 699 predictions in hover and forward flight (airplane mode).

Isolated Proprotor Performance↗

NASA NTRS1982

Technology status report on hydrocarbon-fueled engines for space transportation systems

Liquid oxygen/hydrocarbon (LOX/HC) fueled engines are being considered for use in future high-pressure engines for launch vehicles and as possible replacements for the orbital maneuvering system and reaction control system engines on the Space Shuttle. High performance, reusability, and low life cycle cost are required for these applications. A technology base for these engines is now being established. This paper provides a review of recent results from LOX/HC technology contracts for the National Aeronautics and Space Administration.

La Botz, R. J.↗

NASA NTRS1985

Streamlining: Reducing costs and increasing STS operations effectiveness

The development of streamlining as a concept, its inclusion in the space transportation system engineering and operations support (STSEOS) contract, and how it serves as an incentive to management and technical support personnel is discussed. The mechanics of encouraging and processing streamlining suggestions, reviews, feedback to submitters, recognition, and how individual employee performance evaluations are used to motivation are discussed. Several items that were implemented are mentioned. Information reported and the methodology of determining estimated dollar savings are outlined. The overall effect of this activity on the ability of the McDonnell Douglas flight preparation and mission operations team to support a rapidly increasing flight rate without a proportional increase in cost is illustrated.

Petersburg, R. K.↗

NASA NTRS2008

Polymer Fabric Protects Firefighters, Military, and Civilians

In 1967, NASA contracted with Celanese Corporation, of New York, to develop a line of PBI textiles for use in space suits and vehicles. In 2005, the PBI fiber and polymer business was sold to PBI Performance Products Inc., of Charlotte, North Carolina, under the ownership of the InterTech Group, of North Charleston, South Carolina. PBI Performance Products now offers two distinct lines: PBI, the original heat and flame resistant fiber; and Celazole, a family of high-temperature PBI polymers available in true polymer form. PBI is now used in numerous firefighting, military, motor sports, and other applications.

Source record↗

NASA NTRS2014

ERA Advanced Core Compressor Technology Program

As part of the NASA Integrated Systems Research Program, Environmentally Responsible Aviation Project, NASA GRC and GE Aviation have partnered to investigate the technology barriers associated with improved fuel economy of large gas turbine engines. Crucial to improving fuel economy is the increase in Pressure Ratio (PR) of the core compressor. General Electric is in the process of defining new advanced technology engine concepts and related engine architectures for both commercial and military subsonic and supersonic flight applications. These new concepts and architectures offer the potential of providing substantial improvements in mission fuel burn, emissions, and noise levels relative to SOTA engines and support the needs and goals of future Air force, Navy, and NASA aircraft systems. A key aspect of many of these new engine concepts is an ultra high pressure ratio core compressor. Current SOTA engines such as the GENx utilize a 23:1 class pressure ratio core compressor to achieve an overall pressure ratio in the 50:1 class. Future engines with overall pressure ratios in the 70– 80:1 class will need core compressors with pressure ratios in the 30:1 class. These single spool, ultra high pressure ratio compressors will have inherent challenges. The goal of this work is to provide a dedicated component test vehicle to study the very challenging compressor front stage performance and operability issues that arise in these aggressive machines. With a view to providing highly detailed aerodynamic data that will provide, subject to the rights restrictions for test data afforded under NASA Contract NNC10BA06B/NNC10TA64T, an industry standard data set for CFD validation.

Axial Compressors↗

NASA NTRS2004

NASA Multidimensional Stirling Convertor Code Developed

A high-efficiency Stirling Radioisotope Generator (SRG) for use on potential NASA Space Science missions is being developed by the Department of Energy, Lockheed Martin, Stirling Technology Company, and the NASA Glenn Research Center. These missions may include providing spacecraft onboard electric power for deep space missions or power for unmanned Mars rovers. Glenn is also developing advanced technology for Stirling convertors, aimed at substantially improving the specific power and efficiency of the convertor and the overall power system. Performance and mass improvement goals have been established for second- and third-generation Stirling radioisotope power systems. Multiple efforts are underway to achieve these goals, both in house at Glenn and under various grants and contracts. These efforts include the development of a multidimensional Stirling computational fluid dynamics code, high-temperature materials, advanced controllers, an end-to-end system dynamics model, low-vibration techniques, advanced regenerators, and a lightweight convertor. Under a NASA grant, Cleveland State University (CSU) and its subcontractors, the University of Minnesota (UMN) and Gedeon Associates, have developed a twodimensional computer simulation of a CSUmod Stirling convertor. The CFD-ACE commercial software developed by CFD Research Corp. of Huntsville, Alabama, is being used. The CSUmod is a scaled version of the Stirling Technology Demonstrator Convertor (TDC), which was designed and fabricated by the Stirling Technology Company and is being tested by NASA. The schematic illustrates the structure of this model. Modeled are the fluid-flow and heat-transfer phenomena that occur in the expansion space, the heater, the regenerator, the cooler, the compression space, the surrounding walls, and the moving piston and displacer. In addition, the overall heat transfer, the indicated power, and the efficiency can be calculated. The CSUmod model is being converted to a two-dimensional model of the TDC at NASA Glenn. Validation of the multidimensional Stirling code is an important part of the grant effort. UMN has been generating data in an oscillating-flow test facility using two different test sections: a 90 turn and a cooler/regenerator/heater test section. CSU has created computational fluid dynamics models of both these test sections and has been making comparisons with the data, then improving their models to improve the agreement with the test data. CSU has also been using data available in the literature for code validation. UMN is now preparing to begin fabrication of a new 180 turn test section that will be more representative of certain portions of the Stirling engine geometry. Simulations to almost periodic steady state with the two-dimensional CSUmod model indicate that, to reach periodic steady state on a single 2-GHz desktop computer, 75 to 100 complete simulation cycles would be required and between 1 and 2 months of computer time. Therefore, Glenn has purchased the first 8 computers, of a 64-computer cluster, to be run in parallel to accelerate the simulation. On the basis of CFD Research Corp.'s experience with running the parallelized version of CFD-ACE on their clusters, we estimate that the complete 64-computer cluster will reduce simulation computing time by a factor of about 40. Plans are to continue development of these multidimensional Stirling codes and to use them to study the fluid-flow and heat-transfer phenomena that occur inside Stirling convertors. This is expected to lead to improved thermodynamic loss understanding, onedimensional design and performance codes, and engine performance.

Tew, Roy C.↗

NASA NTRS2012

Science Benefits of Onboard Spacecraft Navigation

Primitive bodies (asteroids and comets), which have remained relatively unaltered since their formation, are important targets for scientific missions that seek to understand the evolution of the solar system. Often the first step is to fly by these bodies with robotic spacecraft. The key to maximizing data returns from these flybys is to determine the spacecraft trajectory relative to the target body-in short, navigate the spacecraft- with sufficient accuracy so that the target is guaranteed to be in the instruments' field of view. The most powerful navigation data in these scenarios are images taken by the spacecraft of the target against a known star field (onboard astrometry). Traditionally, the relative trajectory of the spacecraft must be estimated hours to days in advance using images collected by the spacecraft. This is because of (1)!the long round-trip light times between the spacecraft and the Earth and (2)!the time needed to downlink and process navigation data on the ground, make decisions based on the result, and build and uplink instrument pointing sequences from the results. The light time and processing time compromise navigation accuracy considerably, because there is not enough time to use more accurate data collected closer to the target-such data are more accurate because the angular capability of the onboard astrometry is essentially constant as the distance to the target decreases, resulting in better "plane-of- sky" knowledge of the target. Excellent examples of these timing limitations are high-speed comet encounters. Comets are difficult to observe up close; their orbits often limit scientists to brief, rapid flybys, and their coma further restricts viewers from seeing the nucleus in any detail, unless they can view the nucleus at close range. Comet nuclei details are typically discernable for much shorter durations than the roundtrip light time to Earth, so robotic spacecraft must be able to perform onboard navigation. This onboard navigation can be accomplished through a self- contained system that by eliminating light time restrictions dramatically improves the relative trajectory knowledge and control and subsequently increases the amount of quality data collected. Flybys are one-time events, so the system's underlying algorithms and software must be extremely robust. The autonomous software must also be able to cope with the unknown size, shape, and orientation of the previously unseen comet nucleus. Furthermore, algorithms must be reliable in the presence of imperfections and/or damage to onboard cameras accrued after many years of deep-space operations. The AutoNav operational flight software packages, developed by scientists at the Jet Propulsion Laboratory (JPL) under contract with NASA, meet all these requirements. They have been directly responsible for the successful encounters on all of NASA's close-up comet-imaging missions (see Figure !1). AutoNav is the only system to date that has autonomously tracked comet nuclei during encounters and performed autonomous interplanetary navigation. AutoNav has enabled five cometary flyby missions (Table!1) residing on four NASA spacecraft provided by three different spacecraft builders. Using this software, missions were able to process a combined total of nearly 1000 images previously unseen by humans. By eliminating the need to navigate spacecraft from Earth, the accuracy gained by AutoNav during flybys compared to ground-based navigation is about 1!order of magnitude in targeting and 2!orders of magnitude in time of flight. These benefits ensure that pointing errors do not compromise data gathered during flybys. In addition, these benefits can be applied to flybys of other solar system objects, flybys at much slower relative velocities, mosaic imaging campaigns, and other proximity activities (e.g., orbiting, hovering, and descent/ascent).

Autonomy↗

DOE OSTI2020

Ionic/electronic conductivity regulation of n-type polyoxadiazole lithium sulfonate conductive polymer binders for high-performance silicon microparticle anodes

Low-cost silicon microparticles (SiMP), as a substitute for nanostructured silicon, easily suffer from cracks and fractured during the electrochemical cycle. A novel n-type conductive polymer binder with excellent electronic and ionic conductivities as well as good adhesion, has been successfully designed and applied for high-performance SiMP anodes in lithium-ion batteries to address this problem. Its unique features are attributed to the strong electron-withdrawing oxadiazole ring structure with sulfonate polar groups. The combination of rigid and flexible components in the polymer ensures its good mechanical strength and ductility, which is beneficial to suppress the expansion and contraction of SiMP s during the charge/discharge process. By fine-tuning the monomer ratio, the conjugation and sulfonation degrees of the polymer can be precisely controlled to regulate its ionic and electronic conductivities, which has been systematically analyzed with the help of an electrochemical test method, filling in the gap on the conductivity measurement of the polymer in the doping state. The experimental results indicate that the cell with the developed n-type polymer binder and SiMP (~0.5 μm) anodes achieves much better cycling performance than traditional non-conductive binders. It has been considered that the initial capacity of the SiMP anode is controlled by the synergetic effect of ionic and electronic conductivity of the binder, and the capacity retention mainly depends on its electronic conductivity when the ionic conductivity is sufficient. Here, it is worth noting that the fundamental research of this work is also applicable to other battery systems using conductive polymers in order to achieve high energy density, broadening their practical applications.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

NASA NTRS1987

Relations between two-point correlations and pressure strain terms

The structure of the two-point spatial correlations (velocity-velocity, velocity-scalar, and scalar-scalar) were studied with a view to improve turbulence closure models. The linear model for the two-point correlations proposed by Naot provides a method of including the information about the turbulence structure in the turbulence models. The assumptions and adequacy of this model were tested against the homogeneous shear flow simulation data base. The model performs poorly in some details and it is suggested how it may be improved. The models were also tested for rapid pressure-strain terms in a variety of flows including axisymmetric expansion and contraction flows, homogeneous shear flow, channel flow, and boundary layer.

Wolfshtein, Micha↗

NASA NTRS1991

Configuration management plan. System definition and project development. Repository Based Software Engineering (RBSE) program

This is the configuration management Plan for the AdaNet Repository Based Software Engineering (RBSE) contract. This document establishes the requirements and activities needed to ensure that the products developed for the AdaNet RBSE contract are accurately identified, that proposed changes to the product are systematically evaluated and controlled, that the status of all change activity is known at all times, and that the product achieves its functional performance requirements and is accurately documented.

Mckay, Charles↗

NASA NTRS1992

Space Station Freedom - Approaching the critical design phase

The status and future developments of the Space Station Freedom are discussed. To date detailed design drawings are being produced to manufacture SSF hardware. A critical design review (CDR) for the man-tended capability configuration is planned to be performed in 1993 under the SSF program. The main objective of the CDR is to enable the program to make a full commitment to proceed to manufacture parts and assemblies. NASA recently signed a contract with the Russian space company, NPO Energia, to evaluate potential applications of various Russian space hardware for on-going NASA programs.

Kohrs, Richard H.↗

NASA NTRS2011

Blended Wing Body Concept Development with Open Rotor Engine Intergration

The purpose of this study is to perform a systems analysis of a Blended Wing Body (BWB) open rotor concept at the conceptual design level. This concept will be utilized to estimate overall noise and fuel burn performance, leveraging recent test data. This study will also investigate the challenge of propulsion airframe installation of an open rotor engine on a BWB configuration. Open rotor engines have unique problems relative to turbofans. The rotors are open, exposed to flow conditions outside of the engine. The flow field that the rotors are immersed in may be higher than the free stream flow and it may not be uniform, both of these characteristics could increase noise and decrease performance. The rotors sometimes cause changes in the flow conditions imposed on aircraft surfaces. At high power conditions such as takeoff and climb out, the stream tube of air that goes through the rotors contracts rapidly causing the boundary layer on the body upper surface to go through an adverse pressure gradient which could result with separated airflow. The BWB / Open Rotor configuration must be designed to mitigate these problems.

Pitera, David M.↗

NASA NTRS2016

Implementing Reliability Centered Maintenance (RCM) with State of the Art PT&I Technologies

Building on the work that was started two decades ago, Jacobs Space Operations Group has utilized state of the art PTI technologies to assess the current condition of the assets they manage under the Test and Operations Support Contract (TOSC). Specifically, the Asset Management department leveraged the benefits of ultrasound technology to quantify a motor issue in the Liquid Oxygen Storage Area, and troubleshoot the sources prior to loading the tank to perform Verification and Validation (VV) activities. This technology was efficient, easy to implement, and provided system engineers with data on a possible source of the problem. In situations where legacy motors are exhibiting unexpected noises, it may seem easier to remove and refurbish the motor and replace the bearings because that solution resolves most of the common causes of the noise. However, that solution would have involved additional spending and may not have solved issues stemming from the foundation, if those existed. By utilizing the ultrasound equipment provided by UE Systems, the sound profiles allowed Jacobs TOSC team to determine that the issue resembled a faulty bearing. After replacing the bearing, the unexpected noise ceased.

Reliability Centered Maintenance↗

NASA NTRSDate not supplied

Parameterized Study of Heat Load Trends in a Subscale Rotating Detonation Rocket Engine

NASA has developed a subscale rotating detonation rocket engine platform, enabling rapid parameterization of components and their associated performances. A major performance metric of interest for RDREs is the total heat absorbed at a given operating condition and wave mode operation. To investigate this, several sets of hardware were produced to have variation of the contraction ratio, injector geometry, and length. A wide range of total mass flow rates and mixture ratios were also explored using gaseous methane/oxygen. All hardware was produced using laser powder bed fusion GRCop-42, GRX-810, or C-103 alloys depending on the component cooling requirements. Outer and inner body hardware were made from GRCop-42 where heat fluxes were expected to be high and were water cooled through integrated coolant channels. Nozzles were made from C-103 which are radiatively cooled. Finally, the injectors were produced using GRCop-42 or GRX-810 as passive cooling via propellant injection has previously found to be sufficient given the small gap width of exposed injection surface. Total heat load and bulk heat flux measurements to the hot walls are reported. Trends in heat load and heat flux are shown with relation to parameters such as chamber pressure, area ratio, and wave mode. Heat loads between the inner and outer bodies and the chamber and shroud section are compared.

Heat Flux↗

NASA NTRSDate not supplied

Parameterized Study of Heat Load Trends in a Subscale Rotating Detonation Rocket Engine

Heat Loads↗

NASA NTRS2001

On-Orbit ACDS Performance of the Landsat 7 Spacecraft

Landsat 7 is part of NASA's Earth Science Enterprise (ESE). The ESE is committed to developing an understanding of the total Earth system, the effects of natural and human-induced changes on the global environment, and how natural processes affect humans and how humans affect them. The Landsat 7 satellite consists of the spacecraft bus which was provided under a NASA contract with Lockheed Martin Missiles and Space in Philadelphia, PA, and the Enhanced Thematic Mapper-Plus (ETM+) instrument, procured under a NASA contract with Raytheon Santa Barbara Remote Sensing, in Santa Barbara, CA. The Landsat 7 Attitude Control and Determination System (ACDS) provides many essential functions for the operation of the spacecraft bus and for ETM+. The ACDS maintains the required attitude and orbit at the degree of accuracy necessary for power generation, command and telemetry, thermal balance, image acquisition, Gimbaled X-Band Antenna (GXA) pointing and data for image post-processing. Descriptions of the Landsat 7 mission and the ACDS modes and requirements are presented. A brief summary of significant events of the on-orbit initialization and validation period are provided. Finally, the Landsat 7 product generation system is described and the impact that the ACDS performance has on the ground based image processing system is explored.

Sabelhaus, Phillip↗

DOE OSTI2022

Smart Contract Architectures and Templates for Blockchain-based Energy Markets (V.1.0)

Within the field of Transactive Energy Systems (TES), there is an active need for tools that can support and accelerate the development of these new grid solutions. Among the many tools available, blockchain stands out as a viable instrument that can help researchers develop decentralized, autonomous, and tamper-resistant grid applications. In this work, we explore the use of smart contracts (SCs), a subset of blockchain technology, and analyze their applicability to facilitating the implementation of TES solutions. In particular, we focus on presenting areas of opportunity and potential drawbacks, along with use cases that can benefit from this technology building upon previous research developed by Pacific Northwest National Laboratory and other research organizations. This work builds upon the fundamentals of TES and smart contract technology to develop a series of software templates that can be used by industry to build TES-oriented grid solutions. These templates are intended to be platform agnostic and take into consideration the unique properties of SCs and distributed ledger storage mechanisms to ensure actual code implementations remain aware of the limitations of the technology. The proposed templates have the potential to enable software architects to mix and match components to satisfy their application requirements, thereby reducing the number of resources required to implement blockchain-based solutions. These templates are divided into two main components—data and behavioral models. The data models are intended to help software engineers represent the underlying grid objects along with their properties in a ledger-based storage system. The behavioral models are used to describe the processes and actions that actors within a system must perform to achieve a given outcome such as registering an asset, placing a bid, and performing bid clearances. These two components are documented in a Unified Modeling Language (UML) format and are intended for use in SC-based implementations, with special behavioral considerations to account for the asynchronous properties of the underlying ledger and the typical execution model of smart contracts. Finally, future research ideas and potential extensions to this work are discussed. In particular, known limitations and potential improvements of the developed product are identified and expected to be addressed in future revisions of the template model.

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2021

Ion Mobility Spectrometry Characterization of the Intermediate Hydrogen-Containing Gold Cluster Au7(PPh3)7H52+

We employ ion mobility spectrometry and density functional theory to determine the structure of Au7(PPh3)7H52+ (PPh3 = triphenylphosphine) which was recently identified by high mass resolution mass spectrometry. Experimental ion-neutral collision cross sections represent the momentum transfer between the ionic clusters and gas molecules averaged over the relative thermal velocities of the colliding pair, thereby providing structural insights. Theoretical calculations indicate the geometry of Au7(PPh3)7H52+ is similar to Au7(PPh3)7+, with three hydrogen atoms bridging two gold atoms and two hydrogen atoms forming single Au–H bonds. Collision induced dissociation products observed during IMS experiments reveal that smaller hydrogen containing clusters may be produced through fragmentation of Au7(PPh3)7H52+. Our findings indicate that hydrogen containing species like Au7(PPh3)7H52+ act as intermediates in the formation of larger phosphine ligated gold clusters. These results advance the understanding and ability to control the mechanisms of size selective cluster formation which is necessary for scalable synthesis of clusters with tailored properties. This work was supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. M.A.H. acknowledges support from the DOE Science Undergraduate Laboratory Internship (SULI) program. H.H. acknowledges support from the DOE Office of Workforce Development for Teachers and Scientist (WDTS) under the Visiting Faculty Program (VFP). The efforts of K.A.M. and B.H.C. were supported by the Defense Threat Reduction Agency (Grant No. HDTRA1-14-1-0023). The research was performed using EMSL, a national scientific user facility sponsored by the DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is operated by Battelle for DOE under Contract DE-AC05-76RL01830.

Ligare, Marshall R.↗