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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.

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At least 271 records · Page 15

All sources NASA NTRS DOE OSTI

NASA NTRS1993

Constraint checking during error recovery

The system-level software onboard a spacecraft is responsible for recovery from communication, power, thermal, and computer-health anomalies that may occur. The recovery must occur without disrupting any critical scientific or engineering activity that is executing at the time of the error. Thus, the error-recovery software may have to execute concurrently with the ongoing acquisition of scientific data or with spacecraft maneuvers. This work provides a technique by which the rules that constrain the concurrent execution of these processes can be modeled in a graph. An algorithm is described that uses this model to validate that the constraints hold for all concurrent executions of the error-recovery software with the software that controls the science and engineering activities of the spacecraft. The results are applicable to a variety of control systems with critical constraints on the timing and ordering of the events they control.

Lutz, Robyn R.↗

NASA NTRS1994

Re-Engineering the Multimission Command System at the Jet Propulsion Laboratory

This paper will discuss the design and implementation of the command software, especially trade-offs and lessons learned from practical operational use in JPL's Advanced Multimission Operations System.The command system provides an advanced multimission environment for secure, concurrent commanding of multiple spacecraft. The lessons learned have resulted in a re-engineering of the command system, especially in its user interface and new automation capabilities. This paper will also discuss new development work including a multimission command database toolkit, a universal command translator for sequencing and real-time commands, and incorporation of telecommand capabilities for new missions.

re-engineering↗

DOE OSTI2016

Temperature-dependent thermal conductivity in silicon nanostructured materials studied by the Boltzmann transport equation

Nanostructured materials show low thermal conductivity because of the additional scattering due to phonon-boundary interactions. As these interactions are highly sensitive to the mean free path (MFP) of phonons, MFP distributions in nanostructures can be dramatically distorted relative to bulk. Here we calculate the MFP distribution in periodic nanoporous Si for different temperatures, using the recently developed MFP-dependent Boltzmann transport equation. After analyzing the relative contribution of each phonon branch to thermal transport in nanoporous Si, we find that at room temperature optical phonons contribute 17 % to heat transport, compared to 5 % in bulk Si. Interestingly, we observe a constant thermal conductivity over the range 200 K < T < 300 K . Furthermore, we attribute this behavior to the ballistic transport of acoustic phonons with long intrinsic MFP and the temperature dependence of the heat capacity. Our findings, which are in qualitative agreement with the temperature trend of thermal conductivities measured in nanoporous Si-based systems, shed light on the origin of the reduction of thermal conductivity in nanostructured materials and demonstrate the necessity of multiscale heat transport engineering, in which the bulk material and geometry are optimized concurrently.

36 MATERIALS SCIENCE↗

NASA NTRS2013

NASA Tech Briefs: What Does a Microbial Ecologist Do?

Dr. Leslie Bebout works as a microbial ecologist in the Exobiology Branch at NASA's Moffett Field, CA-‐based Ames Research Center. She and her colleagues study the complexities of carbon, nitrogen and hydrogen cycling in early Earth and Mars analog microbial systems. They concurrently are using this systems biology approach to work with engineers to design systems geared to optimize the use of water, light and nutrient resources relevant both to the development of new green technologies and space exploration capabilities.

Garud, Sumedha↗

DOE OSTI2016

NREL Advancements in Methane Conversion Lead to Cleaner Air, Useful Products

Researchers at NREL leveraged the recent on-site development of gas fermentation capabilities and novel genetic tools to directly convert methane to lactic acid using an engineered methanotrophic bacterium. The results provide proof-of-concept data for a gas-to-liquids bioprocess that concurrently produces fuels and chemicals from methane. NREL researchers developed genetic tools to express heterologous genes in methanotrophic organisms, which have historically been difficult to genetically engineer. Using these tools, researchers demonstrated microbial conversion of methane to lactate, a high-volume biochemical precursor predominantly utilized for the production of bioplastics. Methane biocatalysis offers a means to concurrently liquefy and upgrade natural gas and renewable biogas, enabling their utilization in conventional transportation and industrial manufacturing infrastructure. Producing chemicals and fuels from methane expands the suite of products currently generated from biorefineries, municipalities, and agricultural operations, with the potential to increase revenue and significantly reduce greenhouse gas emissions.

09 BIOMASS FUELS↗

NASA NTRS2000

Peroxide Propulsion at the Turn of the Century

A resurgence of interest in peroxide propulsion has occurred in the last years of the 21st Century. This interest is driven by the need for lower cost propulsion systems and the need for storable reusable propulsion systems to meet future space transportation system architectures. NASA and the Air Force are jointly developing two propulsion systems for flight demonstration early in the 21st Century. One system will be a development of Boeing's AR2-3 engine, which was successfully fielded in the 1960s. The other is a new pressure-fed design by Orbital Sciences Corporation for expendable mission requirements. Concurrently NASA and industry are pursuing the key peroxide technologies needed to design, fabricate, and test advanced peroxide engines to meet the mission needs beyond 2005. This paper will present a description of the AR2-3, report the status of its current test program, and describe its intended flight demonstration. This paper will then describe the Orbital 10K engine, the status of its test program, and describe its planned flight demonstration. Finally the paper will present a plan, or technology roadmap, for the development of an advanced peroxide engine for the 21st Century.

Anderson, William E.↗

NASA NTRS2015

Flight Testing Surfaces Engineered for Mitigating Insect Adhesion on a Falcon HU-25C

Insect residue contamination on aircraft wings can decrease fuel efficiency in aircraft designed for natural laminar flow. Insect residues can cause a premature transition to turbulent flow, increasing fuel burn and making the aircraft less environmentally friendly. Surfaces, designed to minimize insect residue adhesion, were evaluated through flight testing on a Falcon HU-25C aircraft flown along the coast of Virginia and North Carolina. The surfaces were affixed to the wing leading edge and the aircraft remained at altitudes lower than 1000 feet throughout the flight to assure high insect density. The number of strikes on the engineered surfaces was compared to, and found to be lower than, untreated aluminum control surfaces flown concurrently. Optical profilometry was used to determine insect residue height and areal coverage. Differences in results between flight and laboratory tests suggest the importance of testing in realistic use environments to evaluate the effectiveness of engineered surface designs.

Shanahan, Michelle↗

DOE OSTI2018

Nanochannel structures in W enhance radiation tolerance

Developing high performance plasma facing materials (PFMs) is one of the greatest challenges for fusion reactors, because PFMs face unprecedented harsh environments including high flux plasma exposure, fast neutron irradiation and large transmutation gas. Tungsten (W) is considered as one of the most promising PFMs. Rapid accumulation of helium (He) atoms in such environments can lead to the He bubbles nucleation and even the formation of nano- to micro-scale “fuzz” on W surface, which greatly degrade the properties of W itself. The possible ejection of large W particulates into the core plasma can cause plasma instabilities. In this paper, we present a new strategy to address the root causes of bubble nucleation and “fuzz” formation by concurrently releasing He outside of W matrix through the nano-engineered channel structure (nanochannels). Comparing to ordinary bulk W, nanochannel W films with high surface-to-volume ratios are found to not only delay the growth of He bubbles, but also suppress the formation of “fuzz” (less than a half of the “fuzz” thickness formation in bulk W). Finally, molecular dynamic (MD) simulation results elucidate that low vacancy formation energy and high He binding energy in the nanochannel surface effectively help He release and affect He clusters distribution in W during He ion irradiation.

"fuzz"↗

NASA NTRS1998

Distributed Parallel Processing and Dynamic Load Balancing Techniques for Multidisciplinary High Speed Aircraft Design

Multidisciplinary design optimization (MDO) for large-scale engineering problems poses many challenges (e.g., the design of an efficient concurrent paradigm for global optimization based on disciplinary analyses, expensive computations over vast data sets, etc.) This work focuses on the application of distributed schemes for massively parallel architectures to MDO problems, as a tool for reducing computation time and solving larger problems. The specific problem considered here is configuration optimization of a high speed civil transport (HSCT), and the efficient parallelization of the embedded paradigm for reasonable design space identification. Two distributed dynamic load balancing techniques (random polling and global round robin with message combining) and two necessary termination detection schemes (global task count and token passing) were implemented and evaluated in terms of effectiveness and scalability to large problem sizes and a thousand processors. The effect of certain parameters on execution time was also inspected. Empirical results demonstrated stable performance and effectiveness for all schemes, and the parametric study showed that the selected algorithmic parameters have a negligible effect on performance.

Krasteva, Denitza T.↗

NASA NTRS2002

How to Quickly Import CAD Geometry into Thermal Desktop

There are several groups at JPL (Jet Propulsion Laboratory) that are committed to concurrent design efforts, two are featured here. Center for Space Mission Architecture and Design (CSMAD) enables the practical application of advanced process technologies in JPL's mission architecture process. Team I functions as an incubator for projects that are in the Discovery, and even pre-Discovery proposal stages. JPL's concurrent design environment is to a large extent centered on the CAD (Computer Aided Design) file. During concurrent design sessions CAD geometry is ported to other more specialized engineering design packages.

Wright, Shonte↗

NASA NTRSDate not supplied

ICME: The Design of Fit-for-Purpose Materials

With the increased emphasis on reducing the cost and time to market of new materials, ICME (Integrated Computational Materials Engineering) has become a fast growing discipline within materials science and engineering. The vision of ICME is compelling in many respects, not only for the value added in reducing time to market for new products with advanced, tailored materials, but also for enhanced efficiency and performance of these materials. Although the challenges and barriers (both technical and cultural) are formidable, substantial cost, schedule, and technical benefits can result from broad development, implementation, and validation of ICME principles. ICME is an integrated approach to the design of products, and the materials that comprise them, by linking material and structural models at multiple time and length scales. NASA’s Transformational Tools and Technology (TTT) Project sponsored a study (performed by a team led by Pratt & Whitney) in 2016 to define the potential 25-year future state required for integrated multiscale modeling of materials and systems (e.g., load-bearing structures) to accelerate the pace and reduce the expense of innovation in future aerospace and aeronautical systems. This talk will briefly review ICME, the findings of the 2040 Vision study, and discuss NASA’s TTT 2040 implementation activities: with special emphasis on recent accomplishments. The 2040 study, NASA CR 2018- 219771, envisions the development of a cyber-physical-social ecosystem comprised of experimentally verified and validated computational models, tools, and techniques, along with the associated digital tapestry, that impacts the entire supply chain to enable cost-effective, rapid, and revolutionary design of fit-for-purpose materials, components, and systems by enabling the engineer to not only “design-with-the” material but also concurrently “design-the” material.

multiscale analysis↗

DOE OSTI2018

Development of predictive capability of cycle-to-cycle variation in dual-fuel engines using supercomputing-based computational fluid dynamics

Cycle-to-cycle variation (CCV) in internal combustion engines is expected due to variabilities in operating conditions such as in-cylinder fuel stratification, mixing behavior, manifold air pressure, injection timing etc. Generally, engine experimental studies provide averaged quantities such as cylinder pressure, emissions, indicated mean effective pressure (IMEP) from multiple cycles and their CCV of IMEP, and CCV of cylinder pressure from consecutive cycles for a given test condition. Capturing 3D spatial distributions of relevant measures such as fuel-air mixing, temperature, turbulence levels and emissions from such experiments is challenging. Computational Fluid Dynamics (CFD) is an alternative to experiments, that can be used effectively to understand the spatial and temporal distributions of parameters of interest.Quantitative understanding of CCV in dual-fuel (DF) engines will accelerate the development and deployment of engines that provide fuel flexibility, economic advantage and emission compliance. Earlier work [1] performed to develop an understanding of the physics of CCV in large-bore, medium-speed, dual-fuel engines was partially successful. That effort entailed a sparse design of experiment (DOE) of full-cylinder geometry, closed-cycle, dual-fuel CFD simulations in which variabilities within some of the identified global parameters were exercised. The Coefficient of Variation (COV) of cylinder pressure was promising compared with experimental COV. This reinforced the understanding of which global parameters are significant contributors to CCV in DF combustion.The authors have used several high-performance supercomputing facilities in the process of developing predicting capability of CCV in large-bore engines, while operating in dual-fuel, diesel and natural gas (NG), combustion mode [1, 2]. In the current study CCV influencing parameters in a diesel-natural gas dual-fuel engine was studied using a 4th order DOE consisting of 137 concurrent cases. These full-geometry, closed-cycle, CFD simulations were run on the Mira supercomputing facility at the Argonne National Laboratory (ANL). This paper describes key learnings of that study along with a validation of the DOE. Further, the CCV prediction methodology, which is applicable to simulation-based design and testing, is described.

Gubba, Sreenivasa Rao↗

NASA NTRS1984

Software modifications to the Demonstration Advanced Avionics Systems (DAAS)

Critical information required for the design of integrated avionics suitable for generation aviation is applied towards software modifications for the Demonstration Advanced Avionics System (DAAS). The program emphasizes the use of data busing, distributed microprocessors, shared electronic displays and data entry devices, and improved functional capability. A demonstration advanced avionics system (DAAS) is designed, built, and flight tested in a Cessna 402, twin engine, general aviation aircraft. Software modifications are made to DAAS at Ames concurrent with the flight test program. The changes are the result of the experience obtained with the system at Ames, and the comments of the pilots who evaluated the system.

Nedell, B. F.↗

NASA NTRS2004

NASA Tech Briefs, June 2004

Topics covered include: COTS MEMS Flow-Measurement Probes; Measurement of an Evaporating Drop on a Reflective Substrate; Airplane Ice Detector Based on a Microwave Transmission Line; Microwave/Sonic Apparatus Measures Flow and Density in Pipe; Reducing Errors by Use of Redundancy in Gravity Measurements; Membrane-Based Water Evaporator for a Space Suit; Compact Microscope Imaging System with Intelligent Controls; Chirped-Superlattice, Blocked-Intersubband QWIP; Charge-Dissipative Electrical Cables; Deep-Sea Video Cameras Without Pressure Housings; RFID and Memory Devices Fabricated Integrally on Substrates; Analyzing Dynamics of Cooperating Spacecraft; Spacecraft Attitude Maneuver Planning Using Genetic Algorithms; Forensic Analysis of Compromised Computers; Document Concurrence System; Managing an Archive of Images; MPT Prediction of Aircraft-Engine Fan Noise; Improving Control of Two Motor Controllers; Electro-deionization Using Micro-separated Bipolar Membranes; Safer Electrolytes for Lithium-Ion Cells; Rotating Reverse-Osmosis for Water Purification; Making Precise Resonators for Mesoscale Vibratory Gyroscopes; Robotic End Effectors for Hard-Rock Climbing; Improved Nutation Damper for a Spin-Stabilized Spacecraft; Exhaust Nozzle for a Multitube Detonative Combustion Engine; Arc-Second Pointer for Balloon-Borne Astronomical Instrument; Compact, Automated Centrifugal Slide-Staining System; Two-Armed, Mobile, Sensate Research Robot; Compensating for Effects of Humidity on Electronic Noses; Brush/Fin Thermal Interfaces; Multispectral Scanner for Monitoring Plants; Coding for Communication Channels with Dead-Time Constraints; System for Better Spacing of Airplanes En Route; Algorithm for Training a Recurrent Multilayer Perceptron; Orbiter Interface Unit and Early Communication System; White-Light Nulling Interferometers for Detecting Planets; and Development of Methodology for Programming Autonomous Agents.

Source record↗

NASA NTRS2011

Licklider Transmission Protocol Implementation

This software is an implementation of the Licklider Transmission Protocol (LTP), a communications protocol intended to support the Bundle Protocol in Delay-Tolerant Network (DTN) operations. LTP is designed to provide retransmission-based reliability over links characterized by extremely long message round-trip times and/or frequent interruptions in connectivity. Communication in interplanetary space is the most prominent example of this sort of environment, and LTP is principally aimed at supporting long-haul reliable transmission over deep-space RF links. Like any reliable transport service employing ARQ (Automatic Repeat re-Quests), LTP is stateful. In order to assure the reception of a block of data it has sent, LTP must retain for possible retransmission all portions of that block which might not have been received yet. In order to do so, it must keep track of which portions of the block are known to have been received so far, and which are not, together with any additional information needed for purposes of retransmitting part, or all, of the block. Long round-trip times mean substantial delay between the transmission of a block of data and the reception of an acknowledgement from the block s destination, signaling arrival of the block. If LTP postponed transmission of additional blocks of data until it received acknowledgement of the arrival of all prior blocks, valuable opportunities to use what little deep space transmission bandwidth is available would be forever lost. For this reason, LTP is based in part on a notion of massive state retention. Any number of requested transmission conversations (sessions) may be concurrently in flight at various displacements along the link between two LTP engines, and the LTP engines must necessarily retain transmission status and retransmission resources for all of them. Moreover, if any of the data of a given block are lost en route, it will be necessary to retain the state of that transmission during an additional round trip while the lost data are retransmitted; even multiple retransmission cycles may be necessary. LTP's possible multiplicity of sessions per association makes it necessary for each segment of application data to include an additional demultiplexing token: a session ID that uniquely identifies the session in which the segment was issued and, implicitly, the block of data being conveyed by this session. This software comprises a prototype implementation developed by Johns Hopkins University APL in cooperation with JPL, together with adaptations that improve the robustness, correctness, and operability of that implementation.

Burleigh, Scott C.↗

NASA NTRS1988

The concurrent common Lisp development environment

A discussion of the Concurrent Common Lisp Development Environment on the iNTEL Personal Super Computer (iPSC) is presented. The advent of AI based engineering design tools has lead to a need for increased performance of computational facilities which support those tools. Gold Hill has approached this problem by directing its efforts to the creation of a concurrent, distributed AI development environment. This discussion focuses on the development tools aspect of the CCLISP environment. The future direction of Gold Hill in the area of distributed AI support environments is also presented.

Source record↗

DOE OSTI2022

In-situ optical monitoring of gas turbine blade coatings under operational extreme environments

High temperature material systems consisting of thermal barrier coatings and the underlying superalloys are key to achieving higher gas temperatures which in turn control engine efficiencies and reduce emissions. With engine temperatures in excess of the limits that metallic blades and vanes can endure, advanced monitoring techniques that ensure the integrity and durability of these coatings are paramount to continuous and safe operation. Optical methods have the benefit of being non-invasive and are able to capture data under limited access available for monitoring the hot-section of turbines. Addressing Topic 5 on Advanced Instrumentation, the research and development effort for this project titled “In situ optical monitoring of gas turbine blade coatings under operational extreme environments” was completed by University of Central Florida researchers, including Raghavan (PI) and Ghosh (co-PI). In this project, the research team leveraged intrinsic properties of coatings and rare-earth dopants as active and intelligent “sensors” through their optical properties. The outcomes of this project pave the way for diagnostics of turbine blade coatings, under operating environments, through the development of the sensing thermal barrier coating configurations, calibration and associated instrumentation while ensuring coating integrity and durability goals are concurrently met.

42 ENGINEERING↗

DOE OSTI2014

COMPOSE-HPC: Software Composition for Extreme Scale Computational Science and Engineering

Software composition is an important aspect of computational science software engineering due to large scale production science codes involving multiple programming languages, execution and concurrency models. To date, programmers must manage the complexity of building and maintaining such systems largely by hand with minimal (if any) automated assistance. As such, a great deal of programmer time is spent generating and maintaining code which leads to a high maintenance and development cost, as well as an increased risk of errors being introduced by hand than would be expected in an automated system. COMPOSE-HPC was a multi-institutional effort, with the Galois contribution focused on a specific area of code analysis and software infrastructure. Specifically, Galois led the design and implementation for the Parser for Annotations in a User-specified Language (PAUL), as well as collaborating with SNL and LLNL on the Retargetable Open Transformation Engine (ROTE). Both components were built on top of the ROSE compiler infrastructure from LLNL. All artifacts developed under the COMPOSE-HPC program are available on the github.com and sourceforge.net open source hosting sites under permissive BSD3 software licenses.

97 MATHEMATICS AND COMPUTING↗