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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 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
NASA NTRS2015

The Two-Column Aerosol Project: Phase I - Overview and Impact of Elevated Aerosol Layers on Aerosol Optical Depth

The Two-Column Aerosol Project (TCAP), conducted from June 2012 through June 2013, was a unique study designed to provide a comprehensive data set that can be used to investigate a number of important climate science questions, including those related to aerosol mixing state and aerosol radiative forcing. The study was designed to sample the atmosphere be tween and within two atmospheric columns; one fixed near the coast of North America (over Cape Cod, MA) and a second moveable column over the Atlantic Ocean several hundred kilometers from the coast. The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF) was deployed at the base of the Cape Cod column, and the ARM Aerial Facility was utilized for the summer and winter intensive observation periods. One important finding from TCAP is that four of six nearly cloud-free flight days had aerosol layers aloft in both the Cape Cod and maritime columns that were detected using the nadir pointing second-generation NASA high-spectral resolution lidar (HSRL-2).These layer s contributed up to 60 of the total observed aerosol optical depth (AOD). Many of these layers were also intercepted by the aircraft configured for in situ sampling, and the aerosol in the layers was found to have increased amounts of biomass burning material and nitrate compared to aerosol found near the surface. In addition, while there was a great deal of spatial and day-to-day variability in the aerosol chemical composition and optical properties, no systematic differences between the two columns were observed.

aerosols↗
NASA NTRS2022

An ODE-Fitting Approach to Estimate Critical Aircraft Performance Parameters for Trajectory Prediction

Ground-based decision support tools (DST) in air traffic management (ATM) typically perform trajectory prediction based on aircraft performance model (APM) parameters, but some or all of these parameters might not be readily available. In particular, the three critical parameters required for trajectory prediction are the thrust setting, drag coefficients, and takeoff weight of the aircraft. Unfortunately, these parameters are coupled and appear together in physics-based kinetic models. Past approaches utilize data from a specific phase of flight (climb, level flight or descent), where one or more of the parameters are assumed to be known and estimate the remaining unknown parameters. This approach introduces bias/errors and also does not extend to scenarios where all of the above parameters are not known with sufficient accuracy. This paper is the first of its kind to propose a generalized framework for simultaneous estimation of all three critical APM parameters (thrust, drag, and mass). The proposed approach utilizes data from both the climb and descent phases and fits the ordinary differential equation for altitude in each phase using historical trajectory data available from radar tracks or ADS-B. The approach yields a set of optimized APM parameters that are best suited to fit each historical flight record. The methodology is applied on on sample flights from three different aircraft types, and the results demonstrate low fit error and consequently will yield a high level of prediction accuracy.

trajectory prediction, aircraft performance model,↗
NASA NTRSDate not supplied

An ODE-Fitting Approach to Estimate Critical Aircraft Performance Parameters for Trajectory Prediction

Ground-based decision support tools (DST) in air traffic management (ATM) typically perform trajectory prediction based on aircraft performance model (APM) parameters, but some or all of these parameters might not be readily available. In particular, the three critical parameters required for trajectory prediction are the thrust setting, drag coefficients, and takeoff weight of the aircraft. Unfortunately, these parameters are coupled and appear together in physics-based kinetic models. Past approaches utilize data from a specific phase of flight (climb, level flight or descent), where one or more of the parameters are assumed to be known and estimate the remaining unknown parameters. This approach introduces bias/errors and also does not extend to scenarios where all of the above parameters are not known with sufficient accuracy. This paper is the first of its kind to propose a generalized framework for simultaneous estimation of all three critical APM parameters (thrust, drag, and mass). The proposed approach utilizes data from both the climb and descent phases and fits the ordinary differential equation for altitude in each phase using historical trajectory data available from radar tracks or ADS-B. The approach yields a set of optimized APM parameters that are best suited to fit each historical flight record. The methodology is applied on on sample flights from three different aircraft types, and the results demonstrate low fit error and consequently will yield a high level of prediction accuracy.

trajectory prediction↗
NASA NTRS1997

Subsonic Aircraft Contrail and Cloud Effects Special Study (SUCCESS)

During recent years interest in the impact of commercial aircraft on the climate has increased. Aircraft might impact climate in a number of ways. Contrails are clearly a direct radiative forcing mechanism. Exhaust emissions, principally soot and sulfate, might indirectly force the climate by modifying the radiative properties of cirrus clouds. The SUCCESS program was carried out to investigate these issues. It also has several other goals including: better understanding the emissions from aircraft, better understanding the formation of cirrus clouds: better understanding the radiative properties of contrails and clouds and their remote sensing; better understanding the heterogeneous chemistry in the upper atmosphere; and developing new instruments of importance to atmospheric chemistry and cloud physics. SUCCESS took place during April and May of 1997. The NASA DC-8, ER-2, T-39, and 757 aircraft were used as in situ sampling, remote sensing, near field sampling, and emission sources respectively. Most of the operations occurred near the DOE's Atmospheric Radiation Measurement Site in Northern Oklahoma. The DOE operated several other aircraft so that on some days as many as six research aircraft flew together. Numerous new instruments functioned during the mission. This talk will present an overview of SUCCESS from the operational point of view, and provide some of the overall scientific highlights.

Toon, O.B.↗
NASA NTRS1997

Subsonic Aircraft Contrail and Cloud Effects Special Study (SUCCESS)

During recent years interest in the impact of commercial aircraft on the climate has increased. Aircraft might impact climate in a number of ways. Contrails are clearly a direct radiative forcing mechanism. Exhaust emissions, principally soot and sulfate, might indirectly radiative force the climate by modifying the properties of cirrus clouds. The SUCCESS program was carried out to investigate these issues. It also had several other goals including: better understanding the emissions from aircraft, better understanding the formation of cirrus clouds: better understanding the radiative properties of contrail and clouds and their remote sensing; better understanding the heterogeneous chemistry in the upper atmosphere; and developing new instruments of importance to atmospheric chemistry and cloud physics. SUCCESS took place during April and May of 1996. The NASA DC-8, ER-2, T-39, and 757 aircraft were used as in situ sampling, remote sensing, near field sampling, and emission sources respectively. Most of the operations occurred near the DOE's Atmospheric Radiation Measurement Site in Northern Oklahoma. The DOE operated several other aircraft so that on some days as many as six research aircraft operated together. Numerous new instruments operated during the mission. This talk will present an overview of SUCCESS from the operational point of view, and provide some of the overall scientific highlights.

Toon, O. B.↗
NASA NTRS1984

Practical aspects of modeling aircraft dynamics from flight data

The purpose of parameter estimation, a subset of system identification, is to estimate the coefficients (such as stability and control derivatives) of the aircraft differential equations of motion from sampled measured dynamic responses. In the past, the primary reason for estimating stability and control derivatives from flight tests was to make comparisons with wind tunnel estimates. As aircraft became more complex, and as flight envelopes were expanded to include flight regimes that were not well understood, new requirements for the derivative estimates evolved. For many years, the flight determined derivatives were used in simulations to aid in flight planning and in pilot training. The simulations were particularly important in research flight test programs in which an envelope expansion into new flight regimes was required. Parameter estimation techniques for estimating stability and control derivatives from flight data became more sophisticated to support the flight test programs. As knowledge of these new flight regimes increased, more complex aircraft were flown. Much of this increased complexity was in sophisticated flight control systems. The design and refinement of the control system required higher fidelity simulations than were previously required.

Iliff, K. W.↗
NASA NTRS1991

The role of the Remotely Augmented Vehicle (RAV) laboratory in flight research

An overview is presented of the unique capabilities and historical significance of the Remotely Augmented Vehicle (RAV) Lab at NASA-Dryden. The role is reviewed of the RAV Lab in enhancing flight test programs and efficient testing of new aircraft control laws. The history of the RAV Lab is discussed with a sample of its application using the X-29 aircraft. The RAV Lab allows for closed or open loop augmentation of the research aircraft while in flight using ground based, high performance real time computers. Telemetry systems transfer sensor and control data between the ground and the aircraft. The RAV capability provides for enhanced computational power, improved flight data quality, and alternate methods for the testing of control system concepts. The Lab is easily reconfigured to reflect changes within a flight program and can be adapted to new flight programs.

Cohen, Dorothea↗
NASA NTRS1991

The role of the remotely augmented vehicle (RAV) laboratory in flight research

This paper presents on overview of the unique capabilities and historical significance of the Remotely Augmented Vehicle (RAV) Laboratory at the NASA Dryden Flight Research Facility. The report reviews the role of the RAV Laboratory in enhancing flight test programs and efficient testing of new aircraft control laws. The history of the RAV Laboratory is discussed with a sample of its application using the X-29 aircraft. The RAV Laboratory allows for closed- or open-loop augmentation of the research aircraft while in flight using ground-based, high performance real-time computers. Telemetry systems transfer sensor and control data between the ground and the aircraft. The RAV capability provides for enhanced computational power, improved flight data quality, and alternate methods for the testing of control system concepts. The Laboratory is easily reconfigured to reflect changes within a flight program and can be adapted to new flight programs.

Cohen, Dorothea↗
NASA NTRSDate not supplied

NASA’s WB-57F High Altitude Research Aircraft is Looking Up: A Flexible and Capable Heliophysics Platform for Coronal Observations During Total Solar Eclipses

NASA's WB-57F "Canberra" high altitude research aircraft is a unique airborne platform that serves a critical need in airborne science. Although the aircraft has been conventionally used for earth observation/remote sensing and in situ atmospheric sampling, research teams have begun to recognize the aircraft’s emerging role in heliophysics research. With the ability to operate at altitudes in excess of 60,000 feet and with a range of over 2,500 miles, the particular capabilities of the WB-57 are unparalleled by other aircraft in the government or commercial spaces. The Canberra has capacity to carry nearly 9,000 pounds of instrumentation across the aircraft, including modular payload areas in the belly, the nose, wing pods, and wing hatches. The WB-57 features a dedicated "person in the loop" sensor equipment operator, real-time high bandwidth data link between air and ground, and an on-board data network allowing interoperability between multiple systems and operator interfaces. The aircraft has a truly global reach, and has operated out of airfields all over the world with a minimal personnel footprint. The Program maintains a highly qualified engineering team that will work closely with customer requirements to optimize efficiency of payload installation and operation on the aircraft. NASA maintains its own airworthiness authority, allowing a bespoke "in house" approach to aircraft modifications and instrument integration. This often saves months of coordination and cost when compared with commercial options. On 8 April 2024, the WB-57 program executed a one-of-a-kind observation the corona over North America and provided a first-flight opportunity for several instruments that were historically strictly terrestrial. By integrating imagers, spectrometers, and ionosondes on the aircraft, research team partnerships with Southwest Research Institute, University of Hawai’i Institute for Astronomy, and Virginia Tech have demonstrated new and exciting applications for this venerable platform, were able to effectively eliminate the risk of adverse weather spoiling the data collection during totality, and reduce the amount of atmospheric interference in the collected spectral data.

Airborne Science↗
NASA NTRSDate not supplied

Hemispheric Airborne Measurements of Air Quality (HAMAQ)

Hemispheric Airborne Measurements of Air Quality (HAMAQ, pronounced “hammock”) was selected for funding under NASA’s Earth Venture Suborbital (EVS-4) solicitation. As originally proposed, HAMAQ would have flown under each of the geostationary satellites in the Atmospheric Composition Virtual Constellation (AC-VC). Selected under a reduced budget ($15M), HAMAQ has been descoped to include only sampling under TEMPO. The science objectives and approach are still relevant to the broader constellation, and partnerships are still in place to continue the pursuit of the larger vision of HAMAQ to also sample in Asia and Europe. HAMAQ plans include two deployments in 2028, including the Mexico City megalopolis and a second North American site yet to be selected. The effort will include two aircraft, NASA’s B777 for in situ sampling and G-III for remote sensing. These aircraft will be used to complete the integrated observing system, combining satellite observations, ground-based monitoring, research observations, and air quality modeling. With the long lead time for deployments in 2028, HAMAQ leadership are soliciting feedback on the project white paper available for download at https://science.larc.nasa.gov/HAMAQ.

Laura M Judd↗
DOE OSTI2025

Chemical Imaging of Atmospheric Biomass Burning Particles from North American Wildfires

The effects of biomass burning aerosols (BBA) on radiative forcing and cloud formation depend on chemical composition and the internal structures of individual particles within smoke plumes. To improve our understanding of the chemical and physical properties of BBA emitted at different times of the day and their evolution during atmospheric aging, we conducted a study as a part of the Fire Influence on Regional to Global Environments and Air Quality field campaign. Particle samples were collected onboard a research aircraft from smoke plumes from a wildfire in eastern Oregon during late afternoon and nighttime flights on August 28, 2019. A time-resolved aerosol collector was used to collect samples on substrates for offline spectromicroscopic imaging to investigate the single-particle characteristics of BBA particles. Approximately 20,400 individual particles from 10 selected samples were analyzed using computer-controlled scanning electron microscopy coupled with energy-dispersive X-ray microanalysis, revealing their elemental composition, morphology, and viscosity. Elemental microanalysis indicated that aged potassium is likely found in the form of K 2 SO 4 , KNO 3 , and possible K-organic salts. Further chemical speciation and carbon bonding mapping within individual particles were conducted using synchrotron-based scanning transmission X-ray microscopy (STXM) coupled with near edge X-ray absorption fine structure (NEXAFS) spectroscopy. Real-time, water-soluble light absorption measurements were acquired using a particle-into-liquid sampler instrument coupled to a liquid waveguide capillary cell and total organic analyzer. In the late afternoon samples, 65% of the total particle number population consisted entirely of organic components, compared to 46% in the nighttime particles. These differences were attributed to discrepancies in composition at the time of emission and to the daytime condensation and accumulation of photochemically formed secondary organic material on existing BBA particles, a process that halts at night. Microscopy images indicated that particle viscosity was lower in the nighttime particles (<10 1 Pa·s), likely due to increased relative humidity and a higher contribution from hygroscopic inorganic components. The chemical heterogeneity of individual particles was quantified using STXM-derived mixing state parameters. The nature of carbon bonding within individual particles was inferred from the extent of carbon sp 2 hybridization derived from NEXAFS spectra. Average percentages of sp 2 hybridization range between 40% and 60%, with no noticeable differences between late afternoon and nighttime flights. These findings were compared with the online optical properties of both late afternoon and nighttime smoke plumes, providing valuable insights into the complex relationship between chemical composition and optical properties of BBA particles at different times of the day.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1973

Applications of ERTS-1 data to landscape change in eastern Tennessee

The author has identified the following significant results. The analysis of landscape change in eastern Tennessee from ERTS-1 data is being derived from three avenues of experimentation and analysis: (1) a multi-stage sampling procedure utilizing ground and aircraft imagery for ground truth and control; (2) a densitometric and computer analytical experiment for the analysis of gray tone signatures and comparisons for landscape change detection and monitoring; and (3) an ERTS image enhancement procedure for the detection and analysis of photomorphic regions. Significant results include: maps of strip mining changes and forest inventory, watershed identification and delimitation, and agricultural regions derived from spring plowing patterns appearing on the ERTS-1 imagery.

Rehder, J. B.↗
NASA NTRS1976

A non-gaussian model of continuous atmospheric turbulence for use in aircraft design

A non-Gaussian model of atmospheric turbulence is presented and analyzed. The model is restricted to the regions of the atmosphere where the turbulence is steady or continuous, and the assumptions of homogeneity and stationarity are justified. Also spatial distribution of turbulence is neglected, so the model consists of three independent, stationary stochastic processes which represent the vertical, lateral, and longitudinal gust components. The non-Gaussian and Gaussian models are compared with experimental data, and it is shown that the Gaussian model underestimates the number of high velocity gusts which occur in the atmosphere, while the non-Gaussian model can be adjusted to match the observed high velocity gusts more satisfactorily. Application of the proposed model to aircraft response is investigated, with particular attention to the response power spectral density, the probability distribution, and the level crossing frequency. A numerical example is presented which illustrates the application of the non-Gaussian model to the study of an aircraft autopilot system. Listings and sample results of a number of computer programs used in working with the model are included.

Reeves, P. M.↗
NASA NTRS1980

CF6-6D engine short-term performance deterioration

Studies conducted as part of the NASA-Lewis CF6 jet engine diagnostics program are summarized. An 82-engine sample of DC-10-10 aircraft engine checkout data that were gathered to define the extent and magnitude of CF6-6D short term performance deterioration were analyzed. These data are substantiated by the performance testing and analytical teardown of CF6-6D short term deterioration engine serial number (ESN) 451507.

Kramer, W. H.↗
NASA NTRS1981

AgRISTARS: Interim catalog ground data summary, data acquisition year 1979

To honor numerous requests for information about data holdings, and to facilitate the requirements specifications process, a series of interim catalogs are being developed. The 1979 data acquisition year is covered in this volume with subsequent years to follow under different covers. This catalog lists by state those sample segment numbers for which aircraft data has been acquired and/or field inventory products produced.

Doyle, H. M.↗
NASA NTRS1983

A system study for the application of microcomputers to research flight test techniques

The onboard simulator is a three degree of freedom aircraft behavior simulator which provides parameters used by the interception procedure. These parameters can be used for verifying closed loop performance before flight. The air to air intercept mode is a software package integrated in the simulation process that generates a target motion and performs a tracking procedure that predicts the most likely next target position, for a defined time step. This procedure also updates relative position parameters and gives adequate fire commands. A microcomputer based on an aircraft spin warning system periodically samples the assymetric thrust and yaw rate of an airplane and then issues voice synthesized warnings and /or suggests to the ilot how to respond to the situation.

Smyth, R. K.↗
NASA NTRS1984

Assessment of Techniques for Measuring Tropospheric H Sub x O Sub Y: Summary

The objectives were: (1) to provide an assessment of the capability of the existing sensors of HxOy species at levels characteristic of the nonurban troposphere; (2) to identify those techniques adaptable to real-time measurement (sampled or continuous) onboard an aircraft platform; (3) to address the concern for intercalibration and intercomparison of techniques for measuring specific species; and (4) to recommend promising technologies for research and development for measuring important species for which a capability does not now exist or is presently of inadequate sensitivity.

Source record↗
NASA NTRS1989

Calibration-Tube Dewar

Container maintains reference material for gas chromatography at constant temperature for extended periods. Developed for holding peroxyacetylnitrate (PAN), material unstable at room temperature but stable at 0 degree C. Keeps vial of PAN at this temperature by immersing in mixture of water and ice. Perforated tube surrounds vial, protects from damage by ice but allows cold water to circulate around. Plug with handle removable so ice added through filler tube. O-rings seal joints around removable parts. Substances undergoing phase changes at other temperatures substituted for ice and water if different reference materials and storage temperatures used. Used on research aircraft collecting and analyzing air samples in troposphere and stratosphere.

Herlth, Donald B.↗