SEARCH · Engineering Papers

Results for “TERMINAL”

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.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,135 records · Page 63

All sources NASA NTRS DOE OSTI

NASA NTRSDate not supplied

Initial Analysis of Digitally Enabled Cooperative Operations in Class D Terminal Airspace

The primary contribution of this paper is an initial analysis of integrating digitally enabled cooperative operations (or digital operations for short) with Visual Flight Rules (VFR) and Instrument Flight Rules (IFR) operations in the terminal airspace around a Class D airport, specifically around Fort Worth Alliance airport (KAFW). Enabled by connected digital technologies and automated information exchange, digital operations as envisioned would utilize cooperative practices and operator-responsible separation to ensure safety. In the present study, three conflict management configurations for digital operations were analyzed: 1) centralized with a single instance of a conflict management service to model a scenario with only one fleet operator conducting digital operations or all fleet operators utilizing the same service, 2) federated with two different instances to model a scenario with two different fleet operators conducting digital operations, and 3) fully distributed with a different instance for each digital operation. In simulations in which recorded tracks for VFR and IFR operations were played back and digital operations were modeled that would nominally arrive at KAFW once every 20 minutes (given no conflict resolution maneuvers), there were one or fewer losses of separation (LOS) across the three conflict management configurations. The same result was seen in simulations in which digital operations would nominally arrive at KAFW once every 10 minutes. However, in simulations in which digital operations would nominally arrive at KAFW once every 5 minutes, the number of LOS ranged between six and ten. This highlights the need for follow-on research to investigate the extent to which additional capabilities for digital operations, such as complexity management and/or flow organization, may be needed.

digitally enabled cooperative operations↗

NASA NTRSDate not supplied

A Human-In-The-Loop Simulation for Urban Air Mobility in the Terminal Area

In this presentation we propose a human-in-the-loop experiment to study the potential impact of human engagement in tactical mitigation of delay in terminal area air taxi operations. The air taxi operations being considered herein is an advanced air transportation concept called Urban Air Mobility (UAM). The UAM concept aims to support not only air taxi operations, but also package delivery and emergency response among other use cases. The key innovation over current air transportation lies with the introduction of autonomous aircraft and autonomous air traffic management systems. Development of the UAM system will include transitional midterm phases where some operational services will be provided by a mixture of automation and human actors. Midterm operations present a unique challenge, since the scope of responsibility of automated systems is largely undefined, suggesting the need for direct human participation with little to inform how much human intervention is necessary. Here we assume that traffic management responsibilities require coordination between human actors and automated systems and focus on arrival flows for midterm operations. In the proposed human-in-the-loop simulation, virtual UAM traffic is strategically deconflicted by a Provider of Services for UAM at departure, then tactically managed by a human at the arrival facility. Generated traffic consists of UAM participants flying in UAM exclusive airspace structures, thus isolated from traditional traffic. The human operator is tasked with managing spacing of arrival traffic and executing speed adjustments as deemed necessary. We propose the investigation of three levels of automation assistance: 1) no assistance; 2) spacing violation detection; 3) spacing violation detection and speed adjustment recommendations. Quantitative measures like throughput and delay are used to assess the human's capacity for accommodating airborne delays. Qualitative evaluations such as surveys and open-ended feedback are used to gain insight into human factors. These factors could introduce additional capacity constraints on traffic, independent of physical or technical constraints. Although findings for this study will not be reported as the study has not yet been executed, we conclude with potential outcomes informed by previous simulations in the literature and suggestions for the structure and procedures of midterm human-automation air traffic management.

UAM↗

NASA NTRS2024

Abrupt Reduction in Shipping Emission as an Inadvertent Geoengineering Termination Shock Produces Substantial Radiative Warming

Human activities affect the Earth’s climate through modifying the composition of the atmosphere, which then creates radiative forcing that drives climate change. The warming effect of anthropogenic greenhouse gases has been partially balanced by the cooling effect of anthropogenic aerosols. In 2020, fuel regulations abruptly reduced the emission of sulfur dioxide from international shipping by about 80% and created an inadvertent geoengineering termination shock with global impact. Here we estimate the regulation leads to a radiative forcing of +0.2±0.11Wm-2 averaged over the global ocean.The amount of radiative forcing could lead to a doubling (or more) of the warming rate in the 2020s compared with the rate since 1980 with strong spatiotemporal heterogeneity.The warming effect is consistent with the recent observed strong warming in 2023 and expected to make the 2020s anomalously warm. The forcing represents 80% to the measured increase in planetary heat uptake since 2020. The radiative forcing also has strong hemispheric contrast, which has important implications for precipitation pattern changes. Our result suggests marine cloud brightening may be a viable geoengineering method in temporarily cooling the climate that has its unique challenges due to inherent spatiotemporal heterogeneity.

Tianle Yuan↗

NASA NTRSDate not supplied

Traffic Prediction for Uncommunicative Aircraft in Terminal Airspace: Development Framework and Performance Evaluations

This paper presents an air traffic prediction algorithm that takes observations of an aircraft and classifies aircraft type, estimates the aircraft's intent to and method of joining an airport traffic pattern, and predicts the aircaft's future trajectory. To develop algorithms that enable autonomous aircraft to safely insert into un-towered traffic patterns, several challenges need to be addressed. These challenges range from traffic detection to sensor fusion to own-ship trajectory replanning. Critical to a trajectory replanning algorithm is information regarding the future behavior of all traffic aircraft in the operational environment. The presented traffic prediction algorithm generates this information using regular measurements of traffic aircraft position and velocity to classify the aircraft by speed-class, estimate how the aircraft will approach the runway, and construct a predicted trajectory to the runway including future positions and velocities at specific times. The predictions of the presented algorithm are the necessary inputs for any downstream traffic pattern sequencing and own-ship trajectory planning routines. The presented algorithm is benchmarked using approximately 300 randomized traffic trajectories, spanning four vehicle weight classes and eight traffic entry types. While the algorithm can process multiple traffic vehicles in the terminal area, there is no prediction of traffic-on-traffic interaction. Each traffic vehicle is processed separately.

John D McMinn↗

NASA NTRSDate not supplied

Pathfinding for Airspace with Autonomous Vehicles (PAAV) ACAS Xr Terminal Area Simulation Overview

This presentation provides an overview of an upcoming human-in-the-loop simulation planned by the Pathfinding for Airspace with Autonomous Vehicles (PAAV) subproject, as part of the Air Traffic Management eXploration project. The study will investigate Detect and Avoid (DAA) concepts in and around the DAA terminal area (DTA). The DTA has received little investigation in real-time, pilot-in-the-loop simulation. This study proposes to use current remotely piloted aircraft system (RPAS) pilots to investigate the effectiveness of current DTA requirements using the FAA's Airborne Collision Avoidance System X for Rotorcraft (ACAS Xr) as the DAA system under test. The findings of this stufy will be used to inform DTA and ACAS Xr standards development. This presentation will be provided to RTCA Special Committee 228 as an overview and as an opportunity to collect feedback from the larger RPAS/DAA community on the study design and key scenarios and metrics. The presentation provides a brief overview of open areas of research with ACAS Xr, the experimental design, the simulation environment and the simulation schedule.

advanced air mobility↗

DOE OSTI2021

Bi-terminal pegylated integrin-binding peptides and methods of use thereof

The present invention provides bi-terminal PEGylated peptide conjugates that target an integrin such as αvβ6 integrin. In particular embodiments, the peptide conjugates of the present invention further comprise a biological agent such as an imaging agent or a therapeutic agent, e.g., covalently attached to one of the PEG moieties. The peptide conjugates of the present invention are particularly useful for imaging a tumor, organ, or tissue and for treating integrin-mediated diseases and disorders such as cancer, inflammatory diseases, autoimmune diseases, chronic fibrosis, chronic obstructive pulmonary disease (COPD), lung emphysema, and chronic wounding skin disease. Compositions and kits containing the peptide conjugates of the present invention find utility in a wide range of applications including, e.g., in vivo imaging and immunotherapy.

Hausner, Sven H.↗

DOE OSTI2021

Verifying status of a termination end cap of a microinverter chain

A photovoltaic (PV) system includes a system control module that determines the presence of a microinverter chain termination end cap. The end cap includes an embedded circuit. The embedded circuit includes components having resistive, reactive, or impedance values. A signal source provides a signal through the microinverter chain. A parameter for a sensed signal detected by the system control module is used to determine the presence of the end cap using a change between the parameter for the sense signal and a reference parameter.

Chapman, Patrick L.↗

DOE OSTI2022

Low temperature process for diode termination of fully depleted high resistivity silicon radiation detectors that can be used for shallow entrance windows and thinned sensors

Fabrication of vertical diodes for radiation sensing using a low temperature microwave anneal is provided. This kind of anneal allows the back side processing to be performed after the front side processing is done without damaging the front side structures. This enables a simplified fabrication of thinned detectors compared to a conventional silicon on insulator process. Another feature that this technology enables is a thin entrance window for a detector that also serves as the doped diode termination. Such thin entrance windows are especially suitable for detection of low energy radiation.

Kenney, Christopher J.↗

DOE OSTI2022

Bi-terminal pegylated integrin-binding peptides and methods of use thereof

Hausner, Sven H.↗

DOE OSTI2024

Self-terminating etching processes for post-processing of 3D printed metal alloys

A process is provided to remove a selective amount of material from a metal part fabricated by additive manufacturing in a self-terminating manner. The process can be used to remove support structures and trapped powder from a metal part as well as to smooth surfaces of a 3D printed metal part. In one embodiment, selected surfaces of the metal part are treated to make the selected surfaces at least one of mechanically and chemically unstable. The unstable portion of the metal support can then be removed chemically, electrochemically, with a pressure differential, and/or through vapor-phase etching. In one embodiment, the metal part may comprise one or more of an aluminum alloy, a titanium alloy, and a copper alloy. The process can be used to modify any fluid or vapor-accessible regions and surfaces of a 3D printed metal part.

Hildreth, Owen J.↗

NASA NTRS1945