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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 937 records · Page 52

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NASA NTRS1984

Technology developments for laminar boundary layer control on subsonic transport aircraft

The development of laminar-flow technology for commercial transport aircraft is discussed and illustrated in a review of studies undertaken in the NASA Aircraft Energy Efficiency (ACEE) program since 1976. The early history of laminar-flow-control (LFC) techniques and natural-laminar-flow (NLF) airfoil designs is traced, and the aims of ACEE are outlined. The application of slotted structures, composites, and electron-beam-perforated metals in supercritical LFC airfoils, wing panels, and leading-edge systems is examined; wind-tunnel and flight test results are summarized; studies of high-altitude ice effects are described; and hybrid LFC/NLF designs are characterized. Drawings and photographs are provided.

Wagner, R. D.↗

NASA NTRS1989

Propulsive options for a manned Mars transportation system

In this investigation, five potential manned Mars transportation systems are compared. These options include: (1) a single vehicle, chemically propelled (CHEM) option, (2) a single vehicle, nuclear thermal propulsion (NTP) option, (3) a single vehicle solar electric propulsion (SEP) option, (4) a single vehicle hybrid nuclear electric propulsion (NEP)/CHEM option, and (5) a dual vehicle option (NEP cargo spacecraft and CHEM manned vehicle). In addition to utilizing the initial vehicle weight in low-earth orbit as a measure of mission feasibility, this study addresses the major technological barriers each propulsive scenario must surpass. It is shown that instead of a single clearly superior propulsion system, each means of propulsion may be favored depending upon the specified program policy and the extent of the desired manned flight time. Furthermore, the effect which aerobraking and multiple transfer cycles have upon mission feasibility is considered.

Braun, Robert D.↗

DOE OSTI2022

Observation of Current-Driven Features of 2.5 Mev Ion Bunch With Complete and Efficient 5D Measurements at the SNS Beam Test Facility

The SNS Beam Test Facility research program is focused detailed studies of beam distributions for medium-energy ion beams, with the goal of reconstructing realistic 6D bunch distributions to enable halo prediction. For complete characterization of the initial distribution, scan time scales exponentially with scan dimension. Currently, a full 6D measurement with ~10 points across most dimensions requires 30 hours. However, measurement of the 5D distribution f(x, x’,y,y’,w) can be done very rapidly using a hybrid slit/screen method. This approach requires ~4 hours to obtain at least 32 points/dimension, with very high resolution (0.5 keV) in the energy distribution. This presentation reports on the approach and results for 5D characterization of the initial RFQ-formed bunch. This includes higher-resolution views of previously reported transverse-longitudinal dependence and additional interplane dependencies that were not previously reported.

Ruisard, Kiersten↗

DOE OSTI2020

Validation of Continuous-Energy ENDF/B-VIII.0 16 O, 56 Fe, and 63,65 Cu Cross Sections for Nuclear Criticality Safety Applications

Recently completed cross-section evaluations sponsored in part by the Nuclear Criticality Safety Program were incorporated into the 2018 release of the ENDF/B-VIII.0 cross-section library. Evaluated isotopes of interest to the nuclear data and criticality safety community include 16 O, 56 Fe, and 63,65 Cu. For performance validation, benchmark models defined in the International Criticality Safety Benchmark Evaluation Project Handbook were selected based on energy-integrated k eff sensitivities to total cross sections of interest and compared with experimental values. Of the 102 benchmark configurations that were utilized, 63 are sensitive to 16 O, 32 sensitive to 63,65 Cu, and 25 sensitive to 56 Fe. Selected benchmarks were modeled in SCALE 6.2.3 Criticality Safety Analysis Sequence (CSAS) continuous-energy Monte Carlo k eff calculations with ENDF/B-VII.1, with a hybrid ENDF/B-VII.1 with ENDF/B-VIII.0 data substituted for individual isotopes of interest, and with ENDF/B-VIII.0. ENDF/B-VIII.0 showed improved agreement with experimental k eff for 56 Fe, 63 Cu, elemental copper, and full library substitution while producing lessened agreement for 16 O and 65 Cu. Furthermore, with full library and isotope-specific ENDF/B-VIII.0 performance, a best-case ENDF library was formed by excluding underperforming isotopes’ ENDF/B-VIII.0 data, reverting 16 O and 65 Cu cross sections to ENDF/B-VII.1. This resulted in the average relative deviation between calculated and experimental data improving from 1.45σ for the ENDF/B-VIII.0 library to 1.32σ for the best-case library, relative to benchmark uncertainty.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

NASA NTRS2000

HTMT-class Latency Tolerant Parallel Architecture for Petaflops Scale Computation

Computational Aero Sciences and other numeric intensive computation disciplines demand computing throughputs substantially greater than the Teraflops scale systems only now becoming available. The related fields of fluids, structures, thermal, combustion, and dynamic controls are among the interdisciplinary areas that in combination with sufficient resolution and advanced adaptive techniques may force performance requirements towards Petaflops. This will be especially true for compute intensive models such as Navier-Stokes are or when such system models are only part of a larger design optimization computation involving many design points. Yet recent experience with conventional MPP configurations comprising commodity processing and memory components has shown that larger scale frequently results in higher programming difficulty and lower system efficiency. While important advances in system software and algorithms techniques have had some impact on efficiency and programmability for certain classes of problems, in general it is unlikely that software alone will resolve the challenges to higher scalability. As in the past, future generations of high-end computers may require a combination of hardware architecture and system software advances to enable efficient operation at a Petaflops level. The NASA led HTMT project has engaged the talents of a broad interdisciplinary team to develop a new strategy in high-end system architecture to deliver petaflops scale computing in the 2004/5 timeframe. The Hybrid-Technology, MultiThreaded parallel computer architecture incorporates several advanced technologies in combination with an innovative dynamic adaptive scheduling mechanism to provide unprecedented performance and efficiency within practical constraints of cost, complexity, and power consumption. The emerging superconductor Rapid Single Flux Quantum electronics can operate at 100 GHz (the record is 770 GHz) and one percent of the power required by convention semiconductor logic. Wave Division Multiplexing optical communications can approach a peak per fiber bandwidth of 1 Tbps and the new Data Vortex network topology employing this technology can connect tens of thousands of ports providing a bi-section bandwidth on the order of a Petabyte per second with latencies well below 100 nanoseconds, even under heavy loads. Processor-in-Memory (PIM) technology combines logic and memory on the same chip exposing the internal bandwidth of the memory row buffers at low latency. And holographic storage photorefractive storage technologies provide high-density memory with access a thousand times faster than conventional disk technologies. Together these technologies enable a new class of shared memory system architecture with a peak performance in the range of a Petaflops but size and power requirements comparable to today's largest Teraflops scale systems. To achieve high-sustained performance, HTMT combines an advanced multithreading processor architecture with a memory-driven coarse-grained latency management strategy called "percolation", yielding high efficiency while reducing the much of the parallel programming burden. This paper will present the basic system architecture characteristics made possible through this series of advanced technologies and then give a detailed description of the new percolation approach to runtime latency management.

Sterling, Thomas↗

NASA NTRS1976

Space Tug Docking Study. Volume 5: Cost Analysis

The cost methodology, summary cost data, resulting cost estimates by Work Breakdown Structure (WBS), technical characteristics data, program funding schedules and the WBS for the costing are discussed. Cost estimates for two tasks of the study are reported. The first, developed cost estimates for design, development, test and evaluation (DDT&E) and theoretical first unit (TFU) at the component level (Level 7) for all items reported in the data base. Task B developed total subsystem DDT&E costs and funding schedules for the three candidate Rendezvous and Docking Systems: manual, autonomous, and hybrid.

Source record↗

NASA NTRS1990

Three orbital transfer vehicles

Aerospace engineering students at the Virginia Polytechnic Institute and State University undertook three design projects under the sponsorship of the NASA/USRA Advanced Space Design Program. All three projects addressed cargo and/or crew transportation between low Earth orbit and geosynchronous Earth orbit. Project SPARC presents a preliminary design of a fully reusable, chemically powered aeroassisted vehicle for a transfer of a crew of five and a 6000 to 20000 pound payload. The ASTV project outlines a chemically powered aeroassisted configuration that uses disposable tanks and a relatively small aerobrake to realize propellant savings. The third project, LOCOST, involves a reusable, hybrid laser/chemical vehicle designed for large cargo (up to 88,200 pounds) transportation.

Source record↗

NASA NTRS1990

Advanced Rotorcraft Transmission program - A status report

The work being conducted under the first phase of the joint Army/NASA Advanced Rotorcraft Transmission program is reviewed. The work includes the selection of the Tactical Tilt Rotor (TTR) system and the development plans for assessing advanced component technologies. The TTR drive-system arrangement is outlined, and the comparisons and trade studies of self-aligning bearingless planetary, split torque, and conventional single-stage planetary configurations are presented. The effects of transmission improvements are evaluated, and component development testing is discussed, including noise reduction by active force cancellation, hybrid bidirectional tapered roller bearings, and precision net forged spur gears.

Drago, Raymond J.↗

NASA NTRS2000

Validated Feasibility Study of Integrally Stiffened Metallic Fuselage Panels for Reducing Manufacturing Costs: Cost Assessment of Manufacturing/Design Concepts

The objective of the Integral Airframe Structures (IAS) program was to demonstrate, for an integrally stiffened structural concept, performance and weight equal to "built-up" structure with lower manufacturing cost. This report presents results of the cost assessment for several design configuration/manufacturing method combinations. The attributes of various cost analysis models were evaluated and COSTRAN selected for this study. A process/design cost evaluation matrix was developed based on material, forming, machining, and assembly of structural sub-elements and assembled structure. A hybrid design, made from high-speed machined extruded frames that are mechanically fastened to high-speed machined plate skin/stringer panels, was identified as the most cost-effective manufacturing solution. Recurring labor and material costs of the hybrid design are up to 61 percent less than the current built-up technology baseline. This would correspond to a total cost reduction of $1.7 million per ship set for a 777-sized airplane. However, there are important outstanding issues with regard to the cost of capacity of high technology machinery, and the ability to cost-effectively provide surface finish acceptable to the commercial aircraft industry. The projected high raw material cost of large extrusions also played an important role in the trade-off between plate and extruded concepts.

Metschan, S.↗

NASA NTRS1990

Design/Analysis of the JWST ISIM Bonded Joints for Survivability at Cryogenic Temperatures

A major design and analysis challenge for the JWST ISIM structure is thermal survivability of metal/composite bonded joints below the cryogenic temperature of 30K (-405 F). Current bonded joint concepts include internal invar plug fittings, external saddle titanium/invar fittings and composite gusset/clip joints all bonded to M55J/954-6 and T300/954-6 hybrid composite tubes (75mm square). Analytical experience and design work done on metal/composite bonded joints at temperatures below that of liquid nitrogen are limited and important analysis tools, material properties, and failure criteria for composites at cryogenic temperatures are sparse in the literature. Increasing this challenge is the difficulty in testing for these required tools and properties at cryogenic temperatures. To gain confidence in analyzing and designing the ISIM joints, a comprehensive joint development test program has been planned and is currently running. The test program is designed to produce required analytical tools and develop a composite failure criterion for bonded joint strengths at cryogenic temperatures. Finite element analysis is used to design simple test coupons that simulate anticipated stress states in the flight joints; subsequently the test results are used to correlate the analysis technique for the final design of the bonded joints. In this work, we present an overview of the analysis and test methodology, current results, and working joint designs based on developed techniques and properties.

Bartoszyk, Andrew↗

NASA NTRSDate not supplied

Analysis and Optimization of Baseline Single Aisle Aircraft for Future Electrified Powertrain Flight Demonstrator Comparisons

The purpose of this study is to provide baseline single-aisle vehicles for future comparisons NASA’s Electrified Powertrain Flight Demonstrator (EPFD) turbofan powered Vision Systems. Both a large single-aisle (≈150 passenger) and a small single-aisle (≈100 passenger) vehicle will be analyzed using NASA’s General Aviation Synthesis Program and a modernized Python-based version of this program that enables efficient gradient-based optimization of both the airframe and propulsion that currently is being referred to as GASPy. A technology build-up will be conducted to bring the current State-of-the-art vehicles to a projected 2035 technology level by incorporating estimations for improvements in aerodynamics, structures, and propulsions. These vehicles can be used in NASA’s future EPFD project as baselines to measure the benefits of future hybrid and fully electric aircraft against. The advanced, large single-aisle will then be used to demonstrate the benefits of a coupled engine-airframe optimization for fuel burn reduction.

Carl J Recine↗

NASA NTRS2020

Hybrid AFP/Hand Layup Optimized Blades to Enhance Wind Tunnel Capability Summary of PREDICT 2018 Efforts

A project spanning four-months in 2018 was conducted at the NASA Langley Research Center (LaRC) to advance the state of the art in Automated Fiber Placement (AFP) fabrication of complex carbon fiber wind tunnel blades for NASA wind tunnels. This effort was the first step in developing a methodology for fabricating these complex parts. An AFP robotic system was used to explore whether manufacturing time and cost for production of wind tunnel blades could be reduced. Computer aided design models of the blade surfaces were created, and AFP process planning and programming was employed to study the manufacturability of the shapes. A manufacturing demonstration unit was fabricated to demonstrate a methodology to fabricate a complex shape representative of a wind tunnel blade. The present study revealed that the heater configuration on the LaRC AFP robotic system was the primary constraint that limited its ability to use AFP for wind tunnel blade manufacturing.

carbon-epoxy↗

DOE OSTI2024

Parallel hybrid quantum-classical machine learning for kernelized time-series classification

Supervised time-series classification garners widespread interest because of its applicability throughout a broad application domain including finance, astronomy, biosensors, and many others. Here, in this work, we tackle this problem with hybrid quantum-classical machine learning, deducing pairwise temporal relationships between time-series instances using a timeseries Hamiltonian kernel (TSHK). A TSHK is constructed with a sum of inner products generated by quantum states evolved using a parameterized time evolution operator. This sum is then optimally weighted using techniques derived from multiple kernel learning. Because we treat the kernel weighting step as a differentiable convex optimization problem, our method can be regarded as an end-to-end learnable hybrid quantum-classical-convex neural network, or QCC-net, whose output is a data set-generalized kernel function suitable for use in any kernelized machine learning technique such as the support vector machine (SVM). Using our TSHK as input to a SVM, we classify univariate and multivariate time-series using quantum circuit simulators and demonstrate the efficient parallel deployment of the algorithm to 127-qubit superconducting quantum processors using quantum multi-programming.

97 MATHEMATICS AND COMPUTING↗

NASA NTRS1998

Combined Numerical/Analytical Perturbation Solutions of the Navier-Stokes Equations for Aerodynamic Ejector/Mixer Nozzle Flows

In spite of rapid advances in both scalar and parallel computational tools, the large number of variables involved in both design and inverse problems make the use of sophisticated fluid flow models impractical, With this restriction, it is concluded that an important family of methods for mathematical/computational development are reduced or approximate fluid flow models. In this study a combined perturbation/numerical modeling methodology is developed which provides a rigorously derived family of solutions. The mathematical model is computationally more efficient than classical boundary layer but provides important two-dimensional information not available using quasi-1-d approaches. An additional strength of the current methodology is its ability to locally predict static pressure fields in a manner analogous to more sophisticated parabolized Navier Stokes (PNS) formulations. To resolve singular behavior, the model utilizes classical analytical solution techniques. Hence, analytical methods have been combined with efficient numerical methods to yield an efficient hybrid fluid flow model. In particular, the main objective of this research has been to develop a system of analytical and numerical ejector/mixer nozzle models, which require minimal empirical input. A computer code, DREA Differential Reduced Ejector/mixer Analysis has been developed with the ability to run sufficiently fast so that it may be used either as a subroutine or called by an design optimization routine. Models are of direct use to the High Speed Civil Transport Program (a joint government/industry project seeking to develop an economically.viable U.S. commercial supersonic transport vehicle) and are currently being adopted by both NASA and industry. Experimental validation of these models is provided by comparison to results obtained from open literature and Limited Exclusive Right Distribution (LERD) sources, as well as dedicated experiments performed at Texas A&M. These experiments have been performed using a hydraulic/gas flow analog. Results of comparisons of DREA computations with experimental data, which include entrainment, thrust, and local profile information, are overall good. Computational time studies indicate that DREA provides considerably more information at a lower computational cost than contemporary ejector nozzle design models. Finally. physical limitations of the method, deviations from experimental data, potential improvements and alternative formulations are described. This report represents closure to the NASA Graduate Researchers Program. Versions of the DREA code and a user's guide may be obtained from the NASA Lewis Research Center.

DeChant, Lawrence Justin↗

NASA NTRS2009

Damage Arresting Composites for Shaped Vehicles

This report describes the development of a novel structural solution that addresses the demanding fuselage loading requirements for the Hybrid Wing or Blended Wing Body configurations that are described in NASA NRA subtopic A2A.3, "Materials and Structures for Wing Components and Non-Circular Fuselage." The phase I portion of this task includes a comprehensive finite element model-based structural sizing exercise performed using the BWB airplane configuration to generate internal loads and fuselage panel weights for an advanced Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) structural concept. An accompanying element-level test program is also described which substantiates the analytical results and calculation methods used in the trade study. The phase II plan for the continuation of this research is also included herein.

Velicki, Alex↗

NASA NTRS1986

Space station utilization and commonality

Several potential ways of utilizing the space station, including utilization of learning experiences (such as operations), utilization of specific elements of hardware which can be largely common between the SS and Mars programs, and utilization of the on-orbit SS for transportation node functions were identified and discussed. The probability of using the SS in all of these areas seems very good. Three different ways are discussed of utilizing the then existing Low Earth Orbit (LEO) SS for operational support during assembly and checkout of the Mars Space Vehicle (SV): attaching the SV to the SS; allowing the SV to co-orbit near the SS; and a hybrid of the first 2 ways. Discussion of each of these approaches is provided, and the conclusion is reached that either the co-orbiting or hybrid approach might be preferable. Artists' conception of the modes are provided, and sketches of an assembly system concept (truss structure and subsystems derivable from the SS) which could be used for co-orbiting on-orbit assembly support are provided.

Butler, John↗

NASA NTRS1993

Blade Assessment for Ice Impact (BLASIM). User's manual, version 1.0

The Blade Assessment Ice Impact (BLASIM) computer code can analyze solid, hollow, composite, and super hybrid blades. The solid blade is made up of a single material where hollow, composite, and super hybrid blades are constructed with prescribed composite layup. The properties of a composite blade can be specified by inputting one of two options: (1) individual ply properties, or (2) fiber/matrix combinations. When the second option is selected, BLASIM utilizes ICAN (Integrated Composite ANalyzer) to generate the temperature/moisture dependent ply properties of the composite blade. Two types of geometry input can be given: airfoil coordinates or NASTRAN type finite element model. These features increase the flexibility of the program. The user's manual provides sample cases to facilitate efficient use of the code while gaining familiarity.

Reddy, E. S.↗

NASA NTRS2004

Wave-Particle Interactions As a Driving Mechanism for the Solar Wind

Our research has been focusing on a highly experimentally relevant issue: intermittency of the fluctuating fields in outflowing plasmas. We have contributed to both the theoretical and experimental research of the topic. In particular, we have developed a theoretical model and data analyzing programs to examine the issue of intermittency in space plasma outflows, including the solar wind. As fluctuating electric fields in the solar wind are likely to provide a heating and acceleration mechanism for the ions, our studies of the intermittency in turbulence in space plasma outflows help us toward achieving the goal of comparing major physical mechanisms that contribute to the driving of the fast solar wind. Our new theoretical model extends the utilities of our global hybrid model, which has allowed us to follow the kinetic evolution of the particle distributions along an inhomogeneous field line while the particles are subjected to various physical mechanisms. The physical effects that were considered in the global hybrid model included wave-particle interactions, an ambipolar electric field that was consistent with the particle distributions themselves, and Coulomb collisions. With an earlier version of the global hybrid model, we examined the overall impact on the solar wind flow due to the combination of these physical effects. In particular, we studied the combined effects of two major mechanisms that had been proposed as the drivers of the fast solar wind: (1) velocity filtration effect due to suprathermal electrons; (2) ion cyclotron resonance. Since the approval of this research grant, we have updated the model such that the effects due to these two driving mechanisms can be examined separately, thereby allowing us to compare their contributions to the acceleration of the solar wind. In the next section, we shall demonstrate that the velocity filtration effect is rather insignificant in comparison with that due to ion cyclotron resonance.

Wagner, William J.↗