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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 91 records · Page 5

Mars Surveyor '98 MVACS Robotic Arm Control System Design Concepts

This paper describes the control system design concepts for the Mars Volatiles and Climate Surveyor (MVACS) Robotic Arm which supports the scientific investigations to be conducted as part of the Mars Surveyor '98 Lander project. Novel solutions are presented to some of the unique problems encountered in this demanding space application with its tight constraints on mass, power, volume, and computing power.

control manipulator Mars robot trajectory 4-DOF↗

Integration of Propulsion-Airframe-Aeroacoustic Technologies and Design Concepts for a Quiet Blended-Wing-Body Transport

This paper summarizes the results of studies undertaken to investigate revolutionary propulsion-airframe configurations that have the potential to achieve significant noise reductions over present-day commercial transport aircraft. Using a 300 passenger Blended-Wing-Body (BWB) as a baseline, several alternative low-noise propulsion-airframe-aeroacoustic (PAA) technologies and design concepts were investigated both for their potential to reduce the overall BWB noise levels, and for their impact on the weight, performance, and cost of the vehicle. Two evaluation frameworks were implemented for the assessments. The first was a Multi-Attribute Decision Making (MADM) process that used a Pugh Evaluation Matrix coupled with the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). This process provided a qualitative evaluation of the PAA technologies and design concepts and ranked them based on how well they satisfied chosen design requirements. From the results of the evaluation, it was observed that almost all of the PAA concepts gave the BWB a noise benefit, but degraded its performance. The second evaluation framework involved both deterministic and probabilistic systems analyses that were performed on a down-selected number of BWB propulsion configurations incorporating the PAA technologies and design concepts. These configurations included embedded engines with Boundary Layer Ingesting Inlets, Distributed Exhaust Nozzles installed on podded engines, a High Aspect Ratio Rectangular Nozzle, Distributed Propulsion, and a fixed and retractable aft airframe extension. The systems analyses focused on the BWB performance impacts of each concept using the mission range as a measure of merit. Noise effects were also investigated when enough information was available for a tractable analysis. Some tentative conclusions were drawn from the results. One was that the Boundary Layer Ingesting Inlets provided improvements to the BWB's mission range, by increasing the propulsive efficiency at cruise, and therefore offered a means to offset performance penalties imposed by some of the advanced PAA configurations. It was also found that the podded Distributed Exhaust Nozzle configuration imposed high penalties on the mission range and the need for substantial synergistic performance enhancements from an advanced integration scheme was identified. The High Aspect Ratio Nozzle showed inconclusive noise results and posed significant integration difficulties. Distributed Propulsion, in general, imposed performance penalties but may offer some promise for noise reduction from jet-to-jet shielding effects. Finally, a retractable aft airframe extension provided excellent noise reduction for a modest decrease in range.

Hill, G. A.↗

NASA LaRC Strain Gage Balance Design Concepts

The NASA Langley Research Center (LaRC) has been designing strain-gage balances for more than fifty years. These balances have been utilized in Langley's wind tunnels, which span over a wide variety of aerodynamic test regimes, as well as other ground based test facilities and in space flight applications. As a result, the designs encompass a large array of sizes, loads, and environmental effects. Currently Langley has more than 300 balances available for its researchers. This paper will focus on the design concepts for internal sting mounted strain-gage balances. However, these techniques can be applied to all force measurement design applications. Strain-gage balance concepts that have been developed over the years including material selection, sting, model interfaces, measuring, sections, fabrication, strain-gaging and calibration will be discussed.

Rhew, Ray D.↗

A refined design concept for sulfur-tolerant Pd catalyst supported on zeolite by shape-selective exclusion and hydrogen spillover for hydrogenation of aromatics

Sulfur poisoning of noble metal catalysts has been a major challenge for decades. This work demonstrates the superior sulfur tolerance of a hybrid zeolite-supported Pd catalyst for hydrogenation of tetralin containing benzothiophene. The hybrid catalyst consists of Pd supported on a large-pore acidic zeolite Y (Pd/HY) and a small-pore zeolite A without (Pd/HA) or with surface metal passivation by chemical vapor deposition of SiO 2 (SiO 2 -Pd/HA) and with potassium ion exchange (SiO 2 -Pd/KA). Pd/HY is very active for tetralin hydrogenation but quickly deactivates after exposure to benzothiophene at high concentration of 100 ppm sulfur. The SiO 2 -coated Pd/HA shows no activity for tetralin hydrogenation, but continues to activate H 2 and serve as a source of hydrogen spillover from Pd/HA since these metal sites are protected from thiophenic sulfur due to size-selective exclusion. Adding K ion-exchanged and SiO 2 -coated catalyst SiO 2 -Pd/KA to Pd/HY is even more effective for enhancing sulfur tolerance, both for tetralin hydrogenation and for isomerization of cis-decalin to trans-decalin in the presence of benzothiophene. The turnover frequencies (TOF) of all the catalysts are similar at the exposed sulfur/Pd atomic ratio of around 0.5. With further increase in sulfur/Pd ratio, rapid decline in TOF was observed on Pd/HY, but SiO 2 -Pd/KA + Pd/HY hybrid catalyst shows a significantly higher TOF than that over Pd/HY, even though SiO 2 -Pd/KA or SiO 2 -Pd/HA alone shows no TOF for tetralin hydrogenation. Even after high-dose poisoning at 400 ppm sulfur, the SiO 2 -Pd/KA + Pd/HY hybrid recovered activity more quickly than SiO 2 -Pd/HA + Pd/HY, while the latter in turn is much better than Pd/HY alone. These results point to the higher activity for hydrogen spillover from SiO 2 -Pd/KA where Pd metal sites are protected from not only thiophenic sulfur but also inorganic sulfur H 2 S by shape-selective exclusion. The present work further establishes the validity of shape-selective exclusion and hydrogen spillover in the design concept proposed for a sulfur-tolerant bimodal acidic zeolite-supported metal catalyst for hydrogenation of naphthalene [C.S. Song, Chemtech, 29 (1999) 26–30], and refines the design concept further for limiting the size of small pore in hybrid catalysts to~3 Å for restricting access of H 2 S but allowing entrance of H 2 . Further, this refined design concept is applicable to other supported monometallic and bimetallic catalysts.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Doppler Lidar System Design via Interdisciplinary Design Concept at NASA Langley Research Center - Part I

Optimized designs of the Navigation Doppler Lidar (NDL) instrument for Autonomous Landing Hazard Avoidance Technology (ALHAT) were accomplished via Interdisciplinary Design Concept (IDEC) at NASA Langley Research Center during the summer of 2013. Three branches in the Engineering Directorate and three students were involved in this joint task through the NASA Langley Aerospace Research Summer Scholars (LARSS) Program. The Laser Remote Sensing Branch (LRSB), Mechanical Systems Branch (MSB), and Structural and Thermal Systems Branch (STSB) were engaged to achieve optimal designs through iterative and interactive collaborative design processes. A preliminary design iteration was able to reduce the power consumption, mass, and footprint by removing redundant components and replacing inefficient components with more efficient ones. A second design iteration reduced volume and mass by replacing bulky components with excessive performance with smaller components custom-designed for the power system. Mechanical placement collaboration reduced potential electromagnetic interference (EMI). Through application of newly selected electrical components and thermal analysis data, a total electronic chassis redesign was accomplished. Use of an innovative forced convection tunnel heat sink was employed to meet and exceed project requirements for cooling, mass reduction, and volume reduction. Functionality was a key concern to make efficient use of airflow, and accessibility was also imperative to allow for servicing of chassis internals. The collaborative process provided for accelerated design maturation with substantiated function.

Boyer, Charles M.↗

Design Concepts for Co-Production of Power, Fuels & Chemicals Via Coal/Biomass Mixtures

The overall goal of the program is to develop design concepts, incorporating advanced technologies in areas such as oxygen production, feed systems, gas cleanup, component separations and gas turbines, for integrated and economically viable coal and biomass fed gasification facilities equipped with carbon capture and storage for the following scenarios: (i) coproduction of power along with hydrogen, (ii) coproduction of power along with fuels, (iii) coproduction of power along with petrochemicals, and (iv) coproduction of power along with agricultural chemicals. To achieve this goal, specifically the following objectives are met in this proposed project: (i) identify advanced technology options and innovative preliminary design concepts that synergistically integrate plant subsections, (ii) develop steady state system simulations to predict plant efficiency and environmental signature, (iii) develop plant cost estimates by capacity factoring major subsystems or by major equipment items where required, and then capital, operating and maintenance cost estimates, and (iv) perform techno- economic analyses for the above described coproduction facilities. Thermal efficiencies for the electricity only cases with 90% carbon capture are 38.26% and 36.76% (HHV basis) with the bituminous and the lignite feedstocks respectively. For the coproduction cases (where 50% of the energy exported is in the form of electricity), the electrical efficiency, as expected, is highest for the hydrogen coproduction cases while lowest for the higher alcohols (ethanol) coproduction cases. The electrical efficiencies for Fischer-Tropsch coproduction cases are slightly higher than those for the methanol coproduction cases but it should be noted that the methanol (as well as the higher alcohol) coproduction cases produce the finished coproduct while the Fischer-Tropsch coproduction cases produce a coproduct that requires further processing in a refinery. The cross comparison of the thermal performance between the various coproduct cases is further complicated by the fact that the carbon footprint is not the same when carbon leaving with the coproduct are accounted for. The economic analysis and demand for a particular coproduct in the market place is a more meaningful comparison of the various coproduction scenarios. The first year cost of electricity calculated for the bituminous coal is $\$$102.9/MWh while that for the lignite is $\$$108.1/MWh. The calculated cost of hydrogen ranged from $\$$1.42/kg to $\$$2.77/kg depending on the feedstock, which is lower than the DOE announced hydrogen cost goal of $\$$3.00/kg in July 14, 2005. Methanol cost ranged from $\$$345/MT to $\$$617/MT, while the market price is around $\$$450/MT. For Fischer-Tropsch liquids, the calculated cost ranged from $\$$65/bbl to $\$$112/bbl, which is comparable to the current market price of crude oil at around $\$$100/bbl. It should be noted, however, that F-T liquids contain no sulfur and nitrogen compounds. The calculated cost of alcohol ranged from $\$$4.37/gal to $\$$5.43/gal, while it ranged from $\$$2.20/gal to $\$$3.70/gal in a DOE funded study conducted by Louisiana State University. The Louisiana State University study consisted of a significantly larger plant than our study and benefited from economies of scale. When the plant size in our study is scaled up to similar size as in the Louisiana State University study, cost of alcohol is then reduced to a range of $\$$3.24/gal to $\$$4.28/gal, which is comparable. Urea cost ranged from $\$$307/MT to $\$$428/MT, while the market price is around $\$$480/MT.

20 FOSSIL-FUELED POWER PLANTS↗

Overview and Current Status of Analyses of Potential LEU Design Concepts for TREAT

Neutronic and thermal-hydraulic analyses have been performed to evaluate the performance of different low-enriched uranium (LEU) fuel design concepts for the conversion of the Transient Reactor Test Facility (TREAT) from its current high-enriched uranium (HEU) fuel. TREAT is an experimental reactor developed to generate high neutron flux transients for the testing of nuclear fuels. The goal of this work was to identify an LEU design which can maintain the performance of the existing HEU core while continuing to operate safely. A wide variety of design options were considered, with a focus on minimizing peak fuel temperatures and optimizing the power coupling between the TREAT core and test samples. Designs were also evaluated to ensure that they provide sufficient reactivity and shutdown margin for each control rod bank. Analyses were performed using the core loading and experiment configuration of historic M8 Power Calibration experiments (M8CAL). The Monte Carlo code MCNP was utilized for steady-state analyses, and transient calculations were performed with the point kinetics code TREKIN. Thermal analyses were performed with the COMSOL multi-physics code. Using the results of this study, a new LEU Baseline design concept is being established, which will be evaluated in detail in a future report.

Connaway, H. M.↗

Heat sink structural design concepts for a hypersonic research airplane

Hypersonic research aircraft design requires careful consideration of thermal stresses. This paper relates some of the problems in a heat sink structural design that can be avoided by appropriate selection of design options including material selection, design concepts, and load paths. Data on several thermal loading conditions are presented on various conventional designs including bulkheads, longerons, fittings, and frames. Results indicate that conventional designs are inadequate and that acceptable designs are possible by incorporating innovative design practices. These include nonintegral pressure compartments, ball-jointed links to distribute applied loads without restraining the thermal expansion, and material selections based on thermal compatibility.

Taylor, A. H.↗

Global cost and weight evaluation of fuselage keel design concepts

The Boeing program entitled Advanced Technology Composite Aircraft Structure (ATCAS) is focused on the application of affordable composite technology to pressurized fuselage structure of future aircraft. As part of this effort, a design study was conducted on the keel section of the aft fuselage. A design build team (DBT) approach was used to identify and evaluate several design concepts which incorporated different material systems, fabrication processes, structural configurations, and subassembly details. The design concepts were developed in sufficient detail to accurately assess their potential for cost and weight savings as compared with a metal baseline representing current wide body technology. The cost and weight results, along with an appraisal of performance and producibility risks, are used to identify a globally optimized keel design; one which offers the most promising cost and weight advantages over metal construction. Lastly, an assessment is given of the potential for further cost and weight reductions of the selected keel design during local optimization.

Flynn, B. W.↗

The Solar Probe mission - Mission design concepts and requirements

The Solar Probe concept as studied by the Jet Propulsion Laboratory represents the first mission to combine out-of-the-ecliptic scientific coverage with multiple, close solar encounters (at 4 solar radii). The scientific objectives of the mission have driven the investigation and analysis of several mission design concepts, all optimized to meet the science/mission requirements. This paper reviews those mission design concepts developed, the science objectives that drive the mission design, and the principle mission requirements associated with these various concepts.

Ayon, Juan A.↗

Concept Design a 1.4 MW Inverter for Rotor Loss Minimization in a Partially Superconducting Motor

Partially superconducting machines with cryocooler-cooled rotors are a potential near term technology that can achieve the motor performance needed by future fixed wing electric aircraft. For this type of machine, minimizing cryogenic heat load is one of the keys for enabling high machine performance. Rotor eddy current loss is often the most difficult cryogenic heat load to mitigate due to current ripple from the motor drive. This paper presents the concept design for a 20 kW/kg, 99.5 percent efficient motor drive that has sufficiently low current ripple to enable high performance partially superconducting machines by minimizing eddy current loss in the rotor. The motor drive concept design uses a resonant, interleaved, and multilevel topology to achieve these high-performance metrics with little current ripple. Rotor magnetic loss analysis using NASA’s 1.4 MW High Efficiency Megawatt Motor (HEMM) is used in the design process to down select the motor drive topology and show that the final design generates less than 5 W of magnetic loss in the rotor.

Concept design↗

Fuel design concept to stabilize boiling water reactors

A new BWR design concept is introduced where the standard fuel rod array is augmented with thin metallic fuel elements. The heat transfer characteristics of the thin elements mimic the effect of direct energy deposition and introduces a strong stabilizing effect on density wave oscillations. The metallic fuel elements can be introduced to existing fuel bundle designs where some rods are replaced or part-length fuel rods are augmented with the metallic elements. New fuel rod arrays can be envisioned, and one example is given, to suit the concept of the hybrid oxide-metal concept. Although metal fuels are not commonly utilized in the commercial fleet, they are common in naval applications, which makes the proposed hybrid uniquely suited for the disposition of plutonium.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

Doppler Lidar System Design via Interdisciplinary Design Concept at NASA Langley Research Center - Part III

Optimized designs of the Navigation Doppler Lidar (NDL) instrument for Autonomous Landing Hazard Avoidance Technology (ALHAT) were accomplished via Interdisciplinary Design Concept (IDEC) at NASA Langley Research Center during the summer of 2013. Three branches in the Engineering Directorate and three students were involved in this joint task through the NASA Langley Aerospace Research Summer Scholars (LARSS) Program. The Laser Remote Sensing Branch (LRSB), Mechanical Systems Branch (MSB), and Structural and Thermal Systems Branch (STSB) were engaged to achieve optimal designs through iterative and interactive collaborative design processes. A preliminary design iteration was able to reduce the power consumption, mass, and footprint by removing redundant components and replacing inefficient components with more efficient ones. A second design iteration reduced volume and mass by replacing bulky components with excessive performance with smaller components custom-designed for the power system. The existing power system was analyzed to rank components in terms of inefficiency, power dissipation, footprint and mass. Design considerations and priorities are compared along with the results of each design iteration. Overall power system improvements are summarized for design implementations.

Barnes, Bruce W.↗

Doppler Lidar System Design via Interdisciplinary Design Concept at NASA Langley Research Center - Part II

Optimized designs of the Navigation Doppler Lidar (NDL) instrument for Autonomous Landing Hazard Avoidance Technology (ALHAT) were accomplished via Interdisciplinary Design Concept (IDEC) at NASA Langley Research Center during the summer of 2013. Three branches in the Engineering Directorate and three students were involved in this joint task through the NASA Langley Aerospace Research Summer Scholars (LARSS) Program. The Laser Remote Sensing Branch (LRSB), Mechanical Systems Branch (MSB), and Structural and Thermal Systems Branch (STSB) were engaged to achieve optimal designs through iterative and interactive collaborative design processes. A preliminary design iteration was able to reduce the power consumption, mass, and footprint by removing redundant components and replacing inefficient components with more efficient ones. A second design iteration reduced volume and mass by replacing bulky components with excessive performance with smaller components custom-designed for the power system. Thermal modeling software was used to run steady state thermal analyses, which were used to both validate the designs and recommend further changes. Analyses were run on each redesign, as well as the original system. Thermal Desktop was used to run trade studies to account for uncertainty and assumptions about fan performance and boundary conditions. The studies suggested that, even if the assumptions were significantly wrong, the redesigned systems would remain within operating temperature limits.

Crasner, Aaron I.↗

Design concepts for the development of cooperative problem-solving systems

There are many problem-solving tasks that are too complex to fully automate given the current state of technology. Nevertheless, significant improvements in overall system performance could result from the introduction of well-designed computer aids. We have been studying the development of cognitive tools for one such problem-solving task, enroute flight path planning for commercial airlines. Our goal was two-fold. First, we were developing specific systems designs to help with this important practical problem. Second, we are using this context to explore general design concepts to guide in the development of cooperative problem-solving systems. These designs concepts are described.

Smith, Philip J.↗