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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 559 records · Page 31

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NASA NTRS1977

Validation of the Passenger Ride Quality Apparatus (PRQA) for simulation of aircraft motions for ride-quality research

The NASA passenger ride quality apparatus (PRQA), a ground based motion simulator, was compared to the total in flight simulator (TIFS). Tests were made on PRQA with varying stimuli: motions only; motions and noise; motions, noise, and visual; and motions and visual. Regression equations for the tests were obtained and subsequent t-testing of the slopes indicated that ground based simulator tests produced comfort change rates similar to actual flight data. It was recommended that PRQA be used in the ride quality program for aircraft and that it be validated for other transportation modes.

Bigler, W. B., II↗

NASA NTRS2020

Researching the Effect of Parameter Changes on FUN3D Simulations and ROM Generation

This paper discusses the preliminary background and resulting research conducted on the effect of plateau length on CFD results and ROM generation. Within this research, smaller studies were conducted to assess both CFD and ROM parameters for a determination of best practices. The results in this paper lead to a preliminary assessment of potential best practices for ROM generation moving forward.

Brianna L Blocher↗

NASA NTRS2019

Researching Plant Growth in Amended Martian Regolith Simulant, Photosynthetic Rates of Plants, Seed Surface Decontamination by Plasma Methods, New Crop Development, and Porous Concrete Media

Plant growth research for food production at Kennedy Space Center looks at how future residents of Mars and the Moon will enjoy the sight, smell, taste, and nutrition of plants. Overall, the goal is to provide a sustainable source of healthy food, on long-duration space flights, so astronauts can get the nutrition they need and produce food. The sustainable production of food will aid in the efforts of closed life support. Plants have a vital application for bio regenerative life support as demands for food and oxygen can be provided through photosynthesis, while the carbon dioxide from human respiration is removed. Transpiration is also used in life support processes as waste water that can be recycled through plant systems with the resultant humidity then condensed as clean water. Selected crops will provide the nutrient requirements needed for long duration space flight. Currently, projects in food production are investigating how plants grow in Martian regolith simulant, new crops testing with tomato and pepper cultivars, acquiring real-time photosynthetic data on crops, assessing plant growth in porous concrete media, and the use of plasma for surface decontamination of seeds.

food production↗

DOE OSTI2022

The Ground Truth Program: Simulations as Test Beds for Social Science Research Methods.

Social systems are uniquely complex and difficult to study, but understanding them is vital to solving the world’s problems. The Ground Truth program developed a new way of testing the research methods that attempt to understand and leverage the Human Domain and its associated complexities. The program developed simulations of social systems as virtual world test beds. Not only were these simulations able to produce data on future states of the system under various circumstances and scenarios, but their causal ground truth was also explicitly known. Research teams studied these virtual worlds, facilitating deep validation of causal inference, prediction, and prescription methods. The Ground Truth program model provides a way to test and validate research methods to an extent previously impossible, and to study the intricacies and interactions of different components of research.

97 MATHEMATICS AND COMPUTING↗

NASA NTRS1993

Future directions in flight simulation: A user perspective

Langley Research Center was an early leader in simulation technology, including a special emphasis in space vehicle simulations such as the rendezvous and docking simulator for the Gemini program and the lunar landing simulator used before Apollo. In more recent times, Langley operated the first synergistic six degree of freedom motion platform (the Visual Motion Simulator, or VMS) and developed the first dual-dome air combat simulator, the Differential Maneuvering Simulator (DMS). Each Langley simulator was developed more or less independently from one another with different programming support. At present time, the various simulation cockpits, while supported by the same host computer system, run dissimilar software. The majority of recent investments in Langley's simulation facilities have been hardware procurements: host processors, visual systems, and most recently, an improved motion system. Investments in software improvements, however, have not been of the same order.

Jackson, Bruce↗

NASA NTRS1992

Simulation of Martian surface-atmosphere interaction in a space-simulator: Technical considerations and feasibility

The Space Simulator of the German Aerospace Research Establishment at Cologne, formerly used for testing satellites, is now, since 1987, the central unit within the research sub-program 'Comet-Simulation' (KOSI). The KOSI team has investigated physical processes relevant to comets and their surfaces. As a byproduct we gained experience in sample-handling under simulated space conditions. In broadening the scope of the research activities of the DLR Institute of Space Simulation an extension to 'Laboratory-Planetology' is planned. Following the KOSI-experiments a Mars Surface-Simulation with realistic minerals and surface soil in a suited environment (temperature, pressure, and CO2-atmosphere) is foreseen as the next step. Here, our main interest is centered on thermophysical properties of the Martian surface and energy transport (and related gas transport) through the surface. These laboratory simulation activities can be related to space missions as typical pre-mission and during-the-mission support of the experiments design and operations (simulation in parallel). Post mission experiments for confirmation and interpretation of results are of great value. The physical dimensions of the Space Simulator (cylinder of about 2.5 m diameter and 5 m length) allows for testing and qualification of experimental hardware under realistic Martian conditions.

Moehlmann, D.↗

DOE OSTI2020

Wind Farm Simulation and Layout Optimization in Complex Terrain: Preprint

This work reports on incorporating complex terrain into wind farm simulations for the purpose of layout optimization. Adding complex terrain boundary conditions to NREL's medium fidelity computational fluid dynamics model, WindSE, produces significant separation, flow curvature, and speedup effects that would otherwise be difficult to capture with lower-fidelity models or a flat-terrain assumption. These flow features, in turn, can significantly impact the optimal turbine array layout. We demonstrate the impact of complex terrain on flow in both an idealized and real-world setting, and discuss modifications to the code that enable gradient-based optimization using terrain-aware adjoint gradients. Through several optimization case studies, we show that the layout optimization process takes advantage of speedup effects on terrain high points, and leverages flow curvature effects that modify wake trajectories. This yields substantial power improvements over gridded layouts, and hints at future research directions in simulation and optimization for wake trajectories in complex terrain.

17 WIND ENERGY↗

NASA NTRS1987

A simulation study of the flight dynamics of elastic aircraft. Volume 2: Data

The simulation experiment described addresses the effects of structural flexibility on the dynamic characteristics of a generic family of aircraft. The simulation was performed using the NASA Langley VMS simulation facility. The vehicle models were obtained as part of this research project. The simulation results include complete response data and subjective pilot ratings and comments and so allow a variety of analyses. The subjective ratings and analysis of the time histories indicate that increased flexibility can lead to increased tracking errors, degraded handling qualities, and changes in the frequency content of the pilot inputs. These results, furthermore, are significantly affected by the visual cues available to the pilot.

Waszak, Martin R.↗

NASA NTRS1978

Use of piloted simulation for studies of fighter departure/spin susceptibility

Gilbert, W. P.↗

DOE OSTI2020

Radiation Source Localization Using Surrogate Models Constructed from 3-D Monte Carlo Transport Physics Simulations

Recent research has focused on the development of surrogate models for radiation source localization in a simulated urban domain. We employ the Monte Carlo N-Particle (MCNP) code to provide high- delity simulations of radiation transport within an urban domain. The model is constructed to employ a source location (x, y, z) as input and return the estimated count rate for a set of speci ed detector locations. Because MCNP simulations are computationally expensive, we develop e cient and accurate surrogate models of the detector responses. We construct surrogate models using Gaussian processes (GP) and neural networks (NN) that we train and verify using the MCNP simulations. The trained surrogate models provide an e cient framework for Bayesian inference and experimental design. We employ Delayed Rejection Adaptive Metropolis (DRAM), a Markov Chain Monte Carlo (MCMC) algorithm, to infer the location and intensity of an unknown source. The DRAM results yield a posterior probability distribution for the source's location conditioned on the observed detector count rates. The posterior distribution exhibits regions of high and low probability within the simulated environment identifying potential source locations. In this manner, we can quantify the source location to within at least one of these regions of high probability in the considered cases. Employing these methods, we are able to reduce the space of potential source locations by at least 60%.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

NASA NTRS2012

Air Traffic Management Research at NASA Ames

The Aviation Systems Division at the NASA Ames Research Center conducts leading edge research in air traffic management concepts and technologies. This overview will present concepts and simulation results for research in traffic flow management, safe and efficient airport surface operations, super density terminal area operations, separation assurance and system wide modeling and simulation. A brief review of the ongoing air traffic management technology demonstration (ATD-1) will also be presented. A panel discussion, with Mr. Davis serving as a panelist, on air traffic research will follow the briefing.

Davis, Thomas J.↗

NASA NTRS1987

Research in materials processing using a low gravity simulation aircraft

The feasibility of performing materials experiments aboard the NASA KC-135 low gravity simulation aircraft is demonstrated. The vehicle serves as a research platform which flies parabolic maneuvers. Experiments which have been conducted on board the aircraft are outlined and particular attention is given to tests utilizing optical measurement techniques such as interferometry, schlieren, and holography. It is noted that the KC-135 can be used for crew training, flight hardware checkout, conceptual development, self-sufficient experiments, and research in support of and leading to space flight experiments.

Owen, Robert B.↗

NASA NTRS1996

Simulation model of the F/A-18 high angle-of-attack research vehicle utilized for the design of advanced control laws

The 'f18harv' six degree-of-freedom nonlinear batch simulation used to support research in advanced control laws and flight dynamics issues as part of NASA's High Alpha Technology Program is described in this report. This simulation models an F/A-18 airplane modified to incorporate a multi-axis thrust-vectoring system for augmented pitch and yaw control power and actuated forebody strakes for enhanced aerodynamic yaw control power. The modified configuration is known as the High Alpha Research Vehicle (HARV). The 'f18harv' simulation was an outgrowth of the 'f18bas' simulation which modeled the basic F/A-18 with a preliminary version of a thrust-vectoring system designed for the HARV. The preliminary version consisted of two thrust-vectoring vanes per engine nozzle compared with the three vanes per engine actually employed on the F/A-18 HARV. The modeled flight envelope is extensive in that the aerodynamic database covers an angle-of-attack range of -10 degrees to +90 degrees, sideslip range of -20 degrees to +20 degrees, a Mach Number range between 0.0 and 2.0, and an altitude range between 0 and 60,000 feet.

Strickland, Mark E.↗

NASA NTRS1967

Multidisciplinary research leading to utilization of extraterrestrial resources Quarterly status report, Oct. 1, 1966 - Jan. 1, 1967

Simulated lunar materials research leading to utilization of extraterrestrial resources

EXTRATERRESTRIAL MATTER↗

NASA NTRS1987

Measurement of human pilot dynamic characteristics in flight simulation

Fast Fourier Transform (FFT) and Least Square Error (LSE) estimation techniques were applied to the problem of identifying pilot-vehicle dynamic characteristics in flight simulation. A brief investigation of the effects of noise, input bandwidth and system delay upon the FFT and LSE techniques was undertaken using synthetic data. Data from a piloted simulation conducted at NASA Ames Research Center was then analyzed. The simulation was performed in the NASA Ames Research Center Variable Stability CH-47B helicopter operating in fixed-basis simulator mode. The piloting task consisted of maintaining the simulated vehicle over a moving hover pad whose motion was described by a random-appearing sum of sinusoids. The two test subjects used a head-down, color cathode ray tube (CRT) display for guidance and control information. Test configurations differed in the number of axes being controlled by the pilot (longitudinal only versus longitudinal and lateral), and in the presence or absence of an important display indicator called an 'acceleration ball'. A number of different pilot-vehicle transfer functions were measured, and where appropriate, qualitatively compared with theoretical pilot- vehicle models. Some indirect evidence suggesting pursuit behavior on the part of the test subjects is discussed.

Reedy, James T.↗

NASA NTRS1978

Use of piloted simulation for studies of fighter departure/spin susceptibility

The NASA-Langley Research Center has incorporated into its stall/spin research program on military airplanes the use of piloted, fixed-base simulation to complement the existing matrix of unique research testing techniques. The piloted simulations of fighter stall/departure flight dynamics are conducted on the Langley Differential Maneuvering Simulator (DMS). The objectives of the simulation research are reviewed. The rationale underlying the simulation methods and procedures used in the evaluation of airplane characteristics is presented. The evaluation steps used to assess fighter stall/departure characteristics are discussed. Simulation results are presented to illustrate the flight dynamics phenomena dealt with. The considerable experience accumulated in the conduct of piloted stall/departure simulation indicates that simulation provides a realistic evaluation of an airplane's maneuverability at high angles of attack and an assessment of the departure and spin susceptibility of the airplane. This realism is obtained by providing the pilot a complete simulation of the airplane and control system which can be flown using a realistic cockpit and visual display in simulations of demanding air combat maneuvering tasks. The use of the piloted simulation methods and procedures described were found very effective in identifying stability and control problem areas and in developing automatic control concepts to alleviate many of these problems. A good level of correlation between simulated flight dynamics and flight test results were obtained over the many fighter configurations studied in the simulator.

Gilbert, W. P.↗

NASA NTRS2013

Highly Automated Arrival Management and Control System Suitable for Early NextGen

This is a presentation of previously published work conducted in the development of the Terminal Area Precision Scheduling and Spacing (TAPSS) system. Included are concept and technical descriptions of the TAPSS system and results from human in the loop simulations conducted at Ames Research Center. The Terminal Area Precision Scheduling and Spacing system has demonstrated through research and extensive high-fidelity simulation studies to have benefits in airport arrival throughput, supporting efficient arrival descents, and enabling mixed aircraft navigation capability operations during periods of high congestion. NASA is currently porting the TAPSS system into the FAA TBFM and STARS system prototypes to ensure its ability to operate in the FAA automation Infrastructure. NASA ATM Demonstration Project is using the the TAPSS technologies to provide the ground-based automation tools to enable airborne Interval Management (IM) capabilities. NASA and the FAA have initiated a Research Transition Team to enable potential TAPSS and IM Technology Transfer.

Swenson, Harry N.↗

NASA NTRS1990

Knowledge/geometry-based Mobile Autonomous Robot Simulator (KMARS)

Ongoing applied research is focused on developing guidance system for robot vehicles. Problems facing the basic research needed to support this development (e.g., scene understanding, real-time vision processing, etc.) are major impediments to progress. Due to the complexity and the unpredictable nature of a vehicle's area of operation, more advanced vehicle control systems must be able to learn about obstacles within the range of its sensor(s). A better understanding of the basic exploration process is needed to provide critical support to developers of both sensor systems and intelligent control systems which can be used in a wide spectrum of autonomous vehicles. Elcee Computek, Inc. has been working under contract to the Flight Dynamics Laboratory, Wright Research and Development Center, Wright-Patterson AFB, Ohio to develop a Knowledge/Geometry-based Mobile Autonomous Robot Simulator (KMARS). KMARS has two parts: a geometry base and a knowledge base. The knowledge base part of the system employs the expert-system shell CLIPS ('C' Language Integrated Production System) and necessary rules that control both the vehicle's use of an obstacle detecting sensor and the overall exploration process. The initial phase project has focused on the simulation of a point robot vehicle operating in a 2D environment.

Cheng, Linfu↗