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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 919 records · Page 51
All sourcesNASA NTRSDOE OSTI
NASA NTRS2021

Mineral Dust Cycle in the Multiscale Online Nonhydrostatic AtmospheRe CHemistry Model (Monarch) Version 2.0

We present the dust module in the Multiscale Online Non-hydrostatic AtmospheRe CHemistry model (MONARCH) version 2.0, a chemical weather prediction system that can be used for regional and global modeling at a range of resolutions. The representations of dust processes in MONARCH were upgraded with a focus on dust emission (emission parameterizations, entrainment thresholds, considerations of soil moisture and surface cover), lower boundary conditions (roughness, potential dust sources), and dust–radiation interactions. MONARCH now allows modeling of global and regional mineral dust cycles using fundamentally different paradigms, ranging from strongly simplified to physics-based parameterizations. We present a detailed description of these updates along with four global benchmark simulations, which use conceptually different dust emission parameterizations, and we evaluate the simulations against observations of dust optical depth. We determine key dust parameters, such as global annual emission/deposition flux, dust loading, dust optical depth, mass-extinction efficiency, single-scattering albedo, and direct radiative effects. For dust-particle diameters up to 20 µm, the total annual dust emission and deposition fluxes obtained with our four experiments range between about 3500 and 6000 Tg, which largely depend upon differences in the emitted size distribution. Considering ellipsoidal particle shapes and dust refractive indices that account for size-resolved mineralogy, we estimate the global total (longwave and shortwave) dust direct radiative effect (DRE) at the surface to range between about −0.90 and −0.63 W m−2 and at the top of the atmosphere between −0.20 and −0.28 W m−2. Our evaluation demonstrates that MONARCH is able to reproduce key features of the spatiotemporal variability of the global dust cycle with important and insightful differences between the different configurations.

Dust cycle↗
NASA NTRS2023

Distributed Spacecraft Mission (DSM) Plume Design Reference Mission (DRM) Inter-Satellite Link Modeling, Analysis and Simulation

NASA Goddard Space Flight Center (GSFC) Radical Innovation Initiative (RI2) plans to focus intently on DSM capability advancements in FY22-24. A DSM mission involves multiple spacecraft, arranged in a constellation, to achieve one or more common goals via the use of inter-satellite links (ISL) between the satellites. Recently, the GSFC Internal Research & Development (IRAD) program established Enceladus as a design reference mission (DRM) for the current DSM effort to foster the conceptual development of communication architecture, requirements, and solutions for future DSM ISL, as well as being able to push other research areas of interest. Enceladus is an icy moon of the planet Saturn. The DRM Enceladus mission concept involves a constellation of 24 small satellites, orbiting Enceladus around 100 km altitude in 3 planes, as observing nodes for science measurement. The mission science data will be sent back to Earth through a relay orbiting Saturn, using the constellation’s inter-satellite links. A QualNet/STK simulation model of the Relay and constellation ISL optical and RF links is developed for the design and optimization of the link and orbital parameters, as well as the inter-networking protocols. Delay Tolerant Networking (DTN) is utilized in the application layer modeling. This paper describes the plume DRM mission concept of an Enceladus constellation to relay science data to Earth and includes the proposed communication architecture and operation concepts. We present details of the QualNet/STK engineering model for this communication scenario to simulate the end-to-end data traffic through multiple layers (physical, data link, networking, transport and application). A link analysis for the constellation’s ISL, constellation to Relay and Direct to Earth (DTE) optical link is provided and discussed. The results of end-to-end traffic simulation for the data throughout/latency evaluation and assessment of the communication architecture are presented. The investigation of the concept of optical multiple access (OMA) for the Plume DRM is discussed. The modeling and simulation methodology developed in this paper is applicable to other DSMs in near Earth and deep space such as Earth-Moon L1/L2 and Lunar regions.

Distributed Spacecraft Mission (DSM) Inter-satelli↗
NASA NTRS1979

A kinetic approach to magnetospheric modeling

The earth's magnetosphere is caused by the interaction between the flowing solar wind and the earth's magnetic dipole, with the distorted magnetic field in the outer parts of the magnetosphere due to the current systems resulting from this interaction. It is surprising that even the conceptually simple problem of the collisionless interaction of a flowing plasma with a dipole magnetic field has not been solved. A kinetic approach is essential if one is to take into account the dispersion of particles with different energies and pitch angles and the fact that particles on different trajectories have different histories and may come from different sources. Solving the interaction problem involves finding the various types of possible trajectories, populating them with particles appropriately, and then treating the electric and magnetic fields self-consistently with the resulting particle densities and currents. This approach is illustrated by formulating a procedure for solving the collisionless interaction problem on open field lines in the case of a slowly flowing magnetized plasma interacting with a magnetic dipole.

Whipple, E. C., Jr.↗
NASA NTRS2010

Integration of Rotor Aerodynamic Optimization with the Conceptual Design of a Large Civil Tiltrotor

Coupling of aeromechanics analysis with vehicle sizing is demonstrated with the CAMRAD II aeromechanics code and NDARC sizing code. The example is optimization of cruise tip speed with rotor/wing interference for the Large Civil Tiltrotor (LCTR2) concept design. Free-wake models were used for both rotors and the wing. This report is part of a NASA effort to develop an integrated analytical capability combining rotorcraft aeromechanics, structures, propulsion, mission analysis, and vehicle sizing. The present paper extends previous efforts by including rotor/wing interference explicitly in the rotor performance optimization and implicitly in the sizing.

Acree, C. W., Jr.↗
NASA NTRS1989

A pointing system design concept for Space Station attached payloads

A study has been conducted to recommend a pointing system design and architecture that can accommodate the articulated pointing requirements levied on the Space Station Freedom Attached Payload Pointing System. A conceptual design of a control system is developed using classical rate and position control techniques. A high fidelity simulation testbed has been developed as the principal tool for the pointing performance evaluation. Techniques of model reduction are applied to reduce the model order to a manageable size for incorporation into the testbed. The disturbance rich space station environment has been modeled, and nonlinearities such as bearing friction, motor and sensor noise are also considered. Simulations were performed with representatie payloads at nominal pointing orientations. The results show that the tight instrument pointing requirements and the severe Space Station disturbance environment render a marginal performance for a conventional (direct drive and hardmount) gimbal pointing system, particularly for lightweight payloads. A gimbal system that incorporates a passive base isolator and reactionless actuation appears to provide a significant imporvement in pointing performance over the conventional pointing systems.

Wong, Edward↗
NASA NTRS1993

Automating a human factors evaluation of graphical user interfaces for NASA applications: An update on CHIMES

Capturing human factors knowledge about the design of graphical user interfaces (GUI's) and applying this knowledge on-line are the primary objectives of the Computer-Human Interaction Models (CHIMES) project. The current CHIMES prototype is designed to check a GUI's compliance with industry-standard guidelines, general human factors guidelines, and human factors recommendations on color usage. Following the evaluation, CHIMES presents human factors feedback and advice to the GUI designer. The paper describes the approach to modeling human factors guidelines, the system architecture, a new method developed to convert quantitative RGB primaries into qualitative color representations, and the potential for integrating CHIMES with user interface management systems (UIMS). Both the conceptual approach and its implementation are discussed. This paper updates the presentation on CHIMES at the first International Symposium on Ground Data Systems for Spacecraft Control.

Jiang, Jian-Ping↗
NASA NTRS1996

An aeroelastic analysis of helicopter rotor blades incorporating piezoelectric fiber composite twist actuation

A simple aeroelastic analysis of a helicopter rotor blade incorporating embedded piezoelectric fiber composite, interdigitated electrode blade twist actuators is described. The analysis consist of a linear torsion and flapwise bending model coupled with a nonlinear ONERA based unsteady aerodynamics model. A modified Galerkin procedure is performed upon the rotor blade partial differential equations of motion to develop a system of ordinary differential equations suitable for numerical integration. The twist actuation responses for three conceptual full-scale blade designs with realistic constraints on blade mass are numerically evaluated using the analysis. Numerical results indicate that useful amplitudes of nonresonant elastic twist, on the order of one to two degrees, are achievable under one-g hovering flight conditions for interdigitated electrode poling configurations. Twist actuation for the interdigitated electrode blades is also compared with the twist actuation of a conventionally poled piezoelectric fiber composite blade. Elastic twist produced using the interdigitated electrode actuators was found to be four to five times larger than that obtained with the conventionally poled actuators.

Wilkie, W. Keats↗
NASA NTRS1997

Advanced Design Methodology for Robust Aircraft Sizing and Synthesis

Contract efforts are focused on refining the Robust Design Methodology for Conceptual Aircraft Design. Robust Design Simulation (RDS) was developed earlier as a potential solution to the need to do rapid trade-offs while accounting for risk, conflict, and uncertainty. The core of the simulation revolved around Response Surface Equations as approximations of bounded design spaces. An ongoing investigation is concerned with the advantages of using Neural Networks in conceptual design. Thought was also given to the development of systematic way to choose or create a baseline configuration based on specific mission requirements. Expert system was developed, which selects aerodynamics, performance and weights model from several configurations based on the user's mission requirements for subsonic civil transport. The research has also resulted in a step-by-step illustration on how to use the AMV method for distribution generation and the search for robust design solutions to multivariate constrained problems.

Mavris, Dimitri N.↗
NASA NTRS2003

A Micro-Ultrastable Oscillator (micro-US0) for Micro/Nano Sciencecraft

Syntonics LLC developed a prototype micro-Ultra Stable Oscillator (micro-USO) under a Space Base Technology Grant (NAGS-10395). Syntonics conducted the micro-USO Program in two phases. In Phase I, we developed a set of verified analytical models (including thermal, electrical, and control models) for a baseline USO, conducted a series of six technology studies, and built three approx.9OOg prototype units. These prototypes provided a tool for evaluating competing design topologies. In Phase II we prepared the conceptual design of a approx.100-15Og micro-USO.

Source record↗
NASA NTRS2011

COMPASS Final Report: Saturn Moons Orbiter Using Radioisotope Electric Propulsion (REP): Flagship Class Mission

The COllaborative Modeling and Parametric Assessment of Space Systems (COMPASS) team was approached by the NASA Glenn Research Center (GRC) In-Space Project to perform a design session to develop Radioisotope Electric Propulsion (REP) Spacecraft Conceptual Designs (with cost, risk, and reliability) for missions of three different classes: New Frontier s Class Centaur Orbiter (with Trojan flyby), Flagship, and Discovery. The designs will allow trading of current and future propulsion systems. The results will directly support technology development decisions. The results of the Flagship mission design are reported in this document

Oleson, Steven R.↗
NASA NTRSDate not supplied

Numerical Propulsion System Simulation (NPSS) Power Systems Library

This presentation covers the Numerical Propulsion System Simulation (NPSS) Power Systems Library being developed by NASA. This library is a set of components, models, and interfaces for the NPSS language to enable building electric power system models for electrified propulsion systems. The presentation is to be given at the 3rd annual RVLT Toolchain Workshop, where attendees from across the eVTOL industry will be informed of NASA’s tools for eVTOL conceptual design from the vehicle level down through subsystems including propulsion, noise, electrical power, and others. It covers where the NPSS Power System Library fits into NASA’s RVLT toolchain and RVLT work in general, and will inform the audience of how the tool can be useful in their own work.

Electric vertical takeoff and landing↗
NASA NTRS2024

Intermediate Temperature Ceramic Heat Pipe Modeling and Optimization

Spacecraft nuclear electric propulsion, as well as other emerging technologies, can benefit from heat pipes with optimal performance in the intermediate temperature, 450–700 K, regime. In this work, a 1D model was developed to investigate the performance of halide working fluids coupled with 3D printed-ceramic shells to operate at 500–600 K and interface with a nuclear electric propulsion system. An initial conceptual design and performance limits of a 3D printed-AlN heat pipe radiator with AlBr 3 as the working fluid is presented. An areal density of 5.2 kg/m 2 and mass per unit heat performance of 1.00kg/kW is estimated.

thermal management↗
NASA NTRSDate not supplied

Fundamental Research to Enable In-Situ Resource Utilization for NASA’s Artemis Program and Beyond Taking Place at The Glenn Research Center

In Situ Resource Utilization (ISRU) is regarded by many to be the key to future sustainability in space. The National Aeronautics & Space Administration’s (NASA) Space Technology Mission Directorate (STMD) recently published a list of ranked technology shortfalls. ISRU specific capabilities of ‘Extraction and separation of water from extraterrestrial surface material’, ‘Extraction and separation of oxygen from extraterrestrial surface material’, and ‘Produce propellants and mission consumables from extracted in-situ resources’ are within the top 80 shortfalls identified. A team of researchers and engineers at NASA’s Glenn Research Center (GRC) in Cleveland, Ohio, are performing fundamental research and technology maturation to ensure concepts and technologies are ready to support when the mission architecture is primed for ISRU to activate. Through analytical modeling and initial lab-scale testing, researchers are establishing concepts that mature to more sophisticated tests in relevant environments. Numerous studies are underway assessing fundamental behaviors of regolith during various steps of a conceptual ISRU production plant. This paper shares some of GRC’s recent advancements in ISRU research and technology development, in the hopes of providing valuable information to the ISRU community at large, spark ideas for future collaborative endeavors, as well as spur interest in utilizing some of the world-class expertise and facilities GRC has to offer.

ISRU↗
NASA NTRS2008

Simulation Assisted Risk Assessment Applied to Launch Vehicle Conceptual Design

A simulation-based risk assessment approach is presented and is applied to the analysis of abort during the ascent phase of a space exploration mission. The approach utilizes groupings of launch vehicle failures, referred to as failure bins, which are mapped to corresponding failure environments. Physical models are used to characterize the failure environments in terms of the risk due to blast overpressure, resulting debris field, and the thermal radiation due to a fireball. The resulting risk to the crew is dynamically modeled by combining the likelihood of each failure, the severity of the failure environments as a function of initiator and time of the failure, the robustness of the crew module, and the warning time available due to early detection. The approach is shown to support the launch vehicle design process by characterizing the risk drivers and identifying regions where failure detection would significantly reduce the risk to the crew.

Mathias, Donovan L.↗
NASA NTRS1987

Steady-State Thermal-Analysis Program For Microcomputers

Nodal-network model of heat flow implemented by computer program. Steady State Thermal Analysis Program, STEADY, provides thermal designer with quick and convenient method for calculation of heat loads and temperatures. Used on small nodal networks for conceptual or preliminary thermal design and analysis. Accepts up to 20 nodes of fixed or variable temperatures, with constant or temperature-dependent thermal conductivities, and any set of consistent units. Written in FORTRAN 77.

Petrick, S. W.↗
NASA NTRS1986

Equations of state and constitutive equations

Equations-of state information in the otherwise undeformed state as a starting point for the development of constitutive equations is considered in addition to thermodynamics, free energy functions, and conceptual difficulties including the definition of reference states for strain. V-T effects in the form of the Simha-Somcynsky (1969) equation of state are explicitly discussed, and it is shown how this model can be modified to produce a constitutive equation. Continuum mechanics approaches are considered, and examples are given of developments based on linear viscoelastic theory which directly incorporate stress-induced volume changes, and on large-strain elastic theory.

Landel, Robert F.↗
NASA NTRS1991

Simulating motivated cognition

A research effort to develop a sophisticated computer model of human behavior is described. A computer framework of motivated cognition was developed. Motivated cognition focuses on the motivations or affects that provide the context and drive in human cognition and decision making. A conceptual architecture of the human decision-making approach from the perspective of information processing in the human brain is developed in diagrammatic form. A preliminary version of such a diagram is presented. This architecture is then used as a vehicle for successfully constructing a computer program simulation Dweck and Leggett's findings that relate how an individual's implicit theories orient them toward particular goals, with resultant cognitions, affects, and behavior.

Gevarter, William B.↗
NASA NTRS2005

Modeling the Laser Interferometer Space Antenna Optics

The Laser Interferometer Space Antenna (LISA), shown below, will detect gravitational waves produced by objects such as binary black holes or objects falling into black holes (extreme mass ratio inspirals) over a frequency range of l0(exp -4) to 0.1 Hz. Within the conceptual frame work of Newtonian physics, a gravitational wave produces a strain, (Delta)l/l, with magnitudes of the order of Earth based gravitational wave detectors, such as the Laser Interferometer Gravitational-Wave Observatory (LIGO) project, use Michelson interferometers with arm lengths l = 4 km to detect these strains. Earth induced seismic noise limits ground-based instruments detecting gravitational waves with frequencies lower than approx. 1 Hz.

Waluschka, Eugene↗