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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

The remote sensing of aquatic macrophytes Part 1: Color-infrared aerial photography as a tool for identification and mapping of littoral vegetation. Part 2: Aerial photography as a quantitative tool for the investigation of aquatic ecosystems

Research was initiated to use aerial photography as an investigative tool in studies that are part of an intensive aquatic ecosystem research effort at Lake Wingra, Madison, Wisconsin. It is anticipated that photographic techniques would supply information about the growth and distribution of littoral macrophytes with efficiency and accuracy greater than conventional methods.

Gustafson, T. D.↗
NASA NTRSDate not supplied

Novel Tilting Ducted-Fan Aerial Vehicle Configurations

There has been recent renewed interested in ducted-fan, powered-lift vertical takeoff and landing aircraft vehicles for uninhabited aerial vehicle and urban aerial mobility aerial applications. Early work was conducted in the 1950’s to the late 1980’s into ducted-fan vehicles, especially at the time for military missions. The focus of ducted-fan research began to shift to UAV’s and personal air transportation in the 2000’s. Work in the early 2000’s fostered interest into ducted-fan aerial vehicles for vertical lift planetary aerial vehicle missions, especially for missions to Titan, a moon of Saturn. For example, early work at NASA Ames conducted the first known investigation into oval ducts (with internal tandem fans) to be used for these aerial vehicles. The use of twin oval ducts (with internal tandem fans) allowed the use of quadrotor-style rotor rpm control for vehicle trim (in hover, for transition to high-speed forward flight the addition of a tilt-actuator to pitch the twin oval ducts forward to be aligned with the freestream needed to be added to the control approach. This current study explores open-rotor, single isolated ducted-fan, and full vehicle configuration aerodynamic performance for hover, transition, and cruise regimes for novel tilting ducted-fan aerial vehicle configurations. The objective of this study is to better understand the design aerodynamics trade space for noncircular tilting ducted-fans. The primary analysis tool used in this paper is the mid-fidelity computational fluid dynamics RotCFD tool. Several interesting and largely unexplored rotor-on-rotor (or fan-on-fan), duct-on-rotor, rotor- on-duct, and duct-on-airframe are examined in this paper. Many of these aerodynamic interactions are the key to overall aerial vehicle performance. Limited parametric sweeps of rotor-to-rotor spacing (and, therefore, sizing and shape of the enveloping ducts) for the various duct configurations will also be performed. The trade-offs between duct thrust augmentation in hover versus improved transition controllability versus improved cruise L/D will be discussed for various novel duct configurations. These ducted-fan configurations include oval ducts, ‘figure-eight’ ducts, and ‘B-shaped’ ducts, among others.

Ducted-Fan↗
NASA NTRS1974

The use of color infrared aerial photography in determining salt marsh vegetation and delimiting man-made structures of Lynnhaven Bay, Virginia

Color infrared aerial photography was found to be superior to color aerial photography in an ecological study of Lynnhaven Bay, Virginia. The research was divided into three phases: (1) Determination of the feasibility of correlating color infrared aerial photography with saline wetland species composition and zonation patterns, (2) determination of the accuracy of the aerial interpretation and problems related to the aerial method used; and (3) comparison of developed with undeveloped areas along Lynnhaven Bay's shoreline. Wetland species composition and plant community zonation bands were compared with aerial infrared photography and resulted in a high degree of correlation. Problems existed with changing physical conditions; time of day, aircraft angle and sun angle, making it necessary to use several different characteristics in wetland species identification. The main characteristics used were known zonation patterns, textural signatures and color tones. Lynnhaven Bay's shoreline was 61.5 percent developed.

Holman, R. E., III↗
NASA NTRS2004

Measurements from an Aerial Vehicle: A New Tool for Planetary Exploration

Aerial vehicles fill a unique planetary science measurement gap, that of regional-scale, near-surface observation, while providing a fresh perspective for potential discovery. Aerial vehicles used in planetary exploration bridge the scale and resolution measurement gaps between orbiters (global perspective with limited spatial resolution) and landers (local perspective with high spatial resolution) thus complementing and extending orbital and landed measurements. Planetary aerial vehicles can also survey scientifically interesting terrain that is inaccessible or hazardous to landed missions. The use of aerial assets for performing observations on Mars, Titan, or Venus will enable direct measurements and direct follow-ons to recent discoveries. Aerial vehicles can be used for remote sensing of the interior, surface and atmosphere of Mars, Venus and Titan. Types of aerial vehicles considered are airplane "heavier than air" and airships and balloons "lighter than air". Interdependencies between the science measurements, science goals and objectives, and platform implementation illustrate how the proper balance of science, engineering, and cost, can be achieved to allow for a successful mission. Classification of measurement types along with how those measurements resolve science questions and how these instruments are accommodated within the mission context are discussed.

Wright, Henry S.↗
NASA NTRS2005

Aerial Explorers

This paper presents recent results from a mission architecture study of planetary aerial explorers. In this study, several mission scenarios were developed in simulation and evaluated on success in meeting mission goals. This aerial explorer mission architecture study is unique in comparison with previous Mars airplane research activities. The study examines how aerial vehicles can find and gain access to otherwise inaccessible terrain features of interest. The aerial explorer also engages in a high-level of (indirect) surface interaction, despite not typically being able to takeoff and land or to engage in multiple flights/sorties. To achieve this goal, a new mission paradigm is proposed: aerial explorers should be considered as an additional element in the overall Entry, Descent, Landing System (EDLS) process. Further, aerial vehicles should be considered primarily as carrier/utility platforms whose purpose is to deliver air-deployed sensors and robotic devices, or symbiotes, to those high-value terrain features of interest.

Young, Larry A.↗
NASA NTRS2017

Venus Aerial Platforms and Engineering and Scientific Modeling Needs

NASA’s Planetary Science Division is performing an assessment of the state of technology in aerial platforms for exploration of Venus. A key factor in the design of aerial platforms is knowledge of the Venus environment. Modeling the Venus environment, which is the subject of this workshop, is needed for the design of robust aerial platforms that can carry out their missions successfully. The purpose of this paper is to enumerate the kinds of models that are important for both engineering and scientific aspects of the design of an aerial platform mission. The first meeting of the NASA Aerial Platforms study team took place from May 30 to June 2, 2017 and defined the science that can be performed by aerial platforms. A second study meeting is planned for late November 2017. This paper focuses on the current status.

Thompson, T. W.↗
NASA NTRSDate not supplied

Aerial Vehicle Routing and Scheduling for UAS Traffic Management: A Monte Carlo Tree Search Approach

Numerous unmanned aircraft systems operating at low altitudes to deliver goods and services may one day become ubiquitous in our cities. In the Unmanned Aircraft Systems (UAS) Traffic Management (UTM) framework, such a concept is envisioned, where aerial vehicles operate beyond visual line of sight (BVLOS) within specifically reserved and time stamped “corridors” in the airspace. For example, these corridors or operational intent volumes can connect an aerial vehicle’s origin site to its destination site for package delivery operations. There may also be more than one corridor available for an aerial vehicle to choose from and often different corridors may intersect with one another. Thus, it is imperative to ensure flight trajectories belonging to different aerial vehicles are not in conflict. Per the UTM CONOPs, we assume that a vehicle almost always stays inside its corridor or operational volume. This work provides a framework for strategic deconfliction of UTM or package delivery drones, where we schedule the departure time of all vehicles subject to various temporal constraints (including the corridor deconfliction at the intersections). We present the “multi-route weighted package delivery problem” which serves as an exemplifying model for strategic deconfliction in UTM. In the multi-route weighted package delivery problem, a graph network is given which consists of a set of depots (source) and drop-off (destination) nodes, with multiple routes (defined as a sequence of waypoints) connecting the depots to drop-off nodes. In addition, routes are weighted by the associated ground risk and total travel distance for package delivery. The goal is for a known set of aerial vehicles to depart from the depots, choose a route and take off time, while avoiding conflicts with other aerial vehicles, and minimizing both risk and distance traveled. We provide a mixed integer linear programming (MILP) formulation of the problem, as well as a heuristic solution based on Monte Carlo Tree Search (MCTS) – a method used in game theory and artificial intelligence – to overcome limitations inherent to optimal solvers. Computational results show the advantages of using MCTS over the MILP formulation; the former can provide a sub-optimal solution quickly, and may sometimes even reach an optimal solution, whereas the latter may not even produce a solution in reasonable time. Furthermore, results from both the MILP formulation and MCTS methods were validated using a preliminary agent-based simulator implementing the UTM concept of operations. Thus, the MCTS method can be seen as a scalable solution to the complex multi-route weighted package delivery problem and may possibly be extended to similar complex optimization problems.

Kenny Chour↗
NASA NTRSDate not supplied

Urban Aerial Mobility Networks using Amphibious Vertical Takeoff and Landing Vehicles

This study considers novel urban aerial mobility (UAM) networks that address some of the key operator and community acceptance challenges inherent in proposed UAM operations. This paper seeks to examine three possible approaches to improve operator and community acceptance – specifically targeting cost, safety, and noise. First, the conceptual design space will be examined for VTOL amphibious vehicle technologies, including the implications of onwater versus in-flight time/speed. Second, the implications of minimizing community overflights by flying over-water will be examined. Third, the implications of the partial use of onwater, or near-shore/littoral, vertiports on UAM network performance will be examined. This study considers an alternate design trade space for urban aerial mobility systems. A large number of cities in the United States are located near or surround large bodies of water. Many of these same cities are considered to be candidates for metropolitan aerial transportation systems so as to moderate the impact of urban ground-transportation congestion. This paper will expand discussion and study of notional amphibious VTOL vehicles. There is nothing particularly new with regards to helicopters with amphibious takeoff and landing capability. For example, light rotorcraft have been outfitted with pontoons since the 1950s. Larger utility helicopters – used for carrying offshore oil-rig crew – have been designed, with varying degrees of success, to emergency land in rough waters in case of onboard mechanical system failures. The unique difference for the proposed amphibious UAM vehicles, as compared to these earlier amphibious rotorcraft, is that water operation is the norm rather than the exception and that, further, the water-born operation (and design) of such vehicles can be optimized to yield significant economic and operational benefits over solely UAM land-based stations and operations. Various different amphibious UAM networks will be discussed. A first-order set of analyses – employing novel mission metrics – is presented in this paper that will examine the operational performance of these amphibious networks. In particular, amphibious operations might address critical safety and community acceptance issues. An examination of the aerodynamic and hydrodynamic characteristics of amphibious VTOL UAM vehicles will be presented in this paper. One possible conceptual design for an amphibious UAM vehicle is a hybrid synchropter/hydroplane vehicle. As interest in urban aerial mobility grows, it is worthwhile to consider whether or not amphibious vertical takeoff and landing vehicles can play an important role in providing such mobility.

Urban Aerial Mobility↗
NASA NTRSDate not supplied

The Future of Rotorcraft and other Aerial Vehicles for Mars Exploration

The Ingenuity Mars Helicopter is a technology demonstrator. The hope is that Ingenuity will one day lead to future generations of ever-more capable rotorcraft and other aerial vehicles for Mars exploration and other planetary science missions. This paper builds upon nearly twenty-four years of Mars rotorcraft and planetary aerial vehicle work at NASA Ames Research Center. It is posited that a spectrum of different Mars aerial vehicle mission concepts and capabilities could be developed over the next couple of decades – all of which are now potentially enabled by Ingenuity. A series of technology challenges or problems are also detailed in this paper. These problems are presented as an aid in helping establish a nascent planetary rotorcraft or planetary aerial vehicle research community as well as, maybe, helping realize some of the vehicle/mission concepts discussed in the paper.

Rotorcraft↗
NASA NTRS1965

The Goonhilly 85-ft. steerable dish aerial

The choice of the basic type of aerial for a satellite communication ground station is of major importance in view of its influence on the overall performance, cost and time to complete the installation. In the case of the Post Office satellite communication earth station at Goonhilly Downs, Cornwall, a decision was made early in 1961 to use an 85-ft diameter steerable paraboloidal dish aerial, without a radome for tests with the Telstar and Relay, and other communication satellites. Tests with smaller paraboloidal dish aerials with the feed in the aperture plane had shown that a satisfactory electrical performance could be obtained, and experience with the 250-ft diameter radio telescope at Jodrell Bank had shown that the mechanical problems could be overcome. An important factor in the present case was the limited time--less than one year--available for the design, manufacture, construction and testing of the aerial.

COMMUNICATIONS SATELLITE↗
NASA NTRS1971

Comparison of SLAR images and small-scale, low-sun aerial photographs.

A comparison of side-looking airborne radar (SLAR) images and black and white aerial photos of similar scale and illumination of an area in the Mojave Desert of California shows that aerial photos yield far more information about geology than do SLAR images because of greater resolution, tonal range, and geometric fidelity, and easier use in stereo. Nevertheless, radar can differentiate some materials or surfaces that aerial photos cannot; thus, they should be considered as complementary, rather than competing tools in geologic investigations. The most significant advantage of SLAR, however, is its freedom from the stringent conditions of weather, date, and time that are required by small-scale aerial photos taken with a specified direction and angle of illumination. Indeed, in low latitudes, SLAR is the only way to obtain small-scale images with low illumination from certain directions; moreover, in areas of nearly continuous cloudiness, radar may be the only practical source of small-scale images.

Clark, M. M.↗
NASA NTRS1979

Feasibility of determining flat roof heat losses using aerial thermography

The utility of aerial thermography for determining rooftop heat losses was investigated experimentally using several completely instrumented test roofs with known thermal resistances. Actual rooftop heat losses were obtained both from in-situ instrumentation and aerial thermography obtained from overflights at an altitude of 305 m. In general, the remotely determined roof surface temperatures agreed very well with those obtained from ground measurements. The roof heat losses calculated using the remotely determined roof temperature agreed to within 17% of those calculated from 1/R delta T using ground measurements. However, this agreement may be fortuitous since the convective component of the heat loss is sensitive to small changes in roof temperature and to the average heat transfer coefficient used, whereas the radiative component is less sensitive. This, at this time, it is felt that an acceptable quantitative determination of roof heat losses using aerial thermography is only feasible when the convective term is accurately known or minimized. The sensitivity of the heat loss determination to environmental conditions was also evaluated. The analysis showed that the most reliable quantitative heat loss determinations can probably be obtained from aerial thermography taken under conditions of total cloud cover with low wind speeds and at low ambient temperatures.

Bowman, R. L.↗
NASA NTRS2003

Aeronautics Education, Research, and Industry Alliance (AERIAL) Year 2 Report and Year 3 Proposal

The Aeronautics Education, Research, and Industry Alliance (AERIAL): a comprehensive, multi-faceted NASA EPSCoR 2000 initiative, contributes to the strategic research and technology priorities of NASA while intensifying Nebraska s rapidly growing aeronautics research and development endeavors. AERIAL enables Nebraska researchers to: (a) continue strengthening their collaborative relationships with NASA Field Centers, Codes, and Enterprises; (b) increase the capacity of higher education throughout Nebraska to invigorate and expand aeronautics research; and (c) expedite the development of aeronautics-related research infrastructure and industry in the state. This report contains a summary of AERIAL's activities and accomplishments during the second year of implementation. The AERIAL Year 3 proposal is also included.

Bowen, Brent D.↗
NASA NTRS2004

Initial Efforts toward Mission-Representative Imaging Surveys from Aerial Explorers

Numerous researchers have proposed the use of robotic aerial explorers to perform scientific investigation of planetary bodies in our solar system. One of the essential tasks for any aerial explorer is to be able to perform scientifically valuable imaging surveys. The focus of this paper is to discuss the challenges implicit in, and recent observations related to, acquiring mission-representative imaging data from a small fixed-wing UAV, acting as a surrogate planetary aerial explorer. This question of successfully performing aerial explorer surveys is also tied to other topics of technical investigation, including the development of unique bio-inspired technologies.

Pisanich, Greg↗
NASA NTRS2004

The NASA Dryden AAR Project: A Flight Test Approach to an Aerial Refueling System

The integration of uninhabited aerial vehicles (UAVs) into controlled airspace has generated a new era of autonomous technologies and challenges. Autonomous aerial refueling would enable UAVs to travel further distances and loiter for extended periods over time-critical targets. The NASA Dryden Flight Research Center recently has completed a flight research project directed at developing a dynamic hose and drogue system model to support the development of an automated aerial refueling system. A systematic dynamic model of the hose and drogue system would include the effects of various influences on the system, such as flight condition, hose and drogue type, tanker type and weight, receiver type, and tanker and receiver maneuvering. Using two NASA F/A-18 aircraft and a conventional hose and drogue aerial refueling store from the Navy, NASA has obtained flight research data that document the response of the hose and drogue system to these effects. Preliminary results, salient trends, and important lessons are presented.

Hansen, Jennifer L.↗