SEARCH · Engineering Papers
Results for “forcing”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Orbital motion of dust particles in an rf magnetron discharge. Ion drag force or neutral atom wind force
Microparticles with sizes up to 130 {mu}m have been confined and the velocity and diameter of particles in a plasma trap of an rf magnetron discharge with an arc magnetic field have been simultaneously measured. The motion of the gas induced by electron and ion cyclotron currents has been numerically simulated using the Navier-Stokes equation. The experimental and numerical results confirm the mechanism of the orbital motion of dust particles in the magnetron discharge plasma that is associated with the orbital motion of the neutral gas accelerated by electron and ion drift flows in crossed electric and magnetic fields.
Forced chemical mixing at Cu/Nb Interfaces during severe plastic deformation
Explore the source record for details and available documents.
Analysis of Compact-Forced Simple Shear and Compact-Forced Double Shear Test Specimens for Shear Localization in Materials
This study compares the performance of new test samples developed to produce shear localization in materials.
GeoVision Analysis: Reservoir Maintenance and Development Task Force Report (GeoVision Analysis Supporting Task Force Report : Reservoir Maintenance and Development)
This report documents the key findings from the Reservoir Maintenance and Development (RM&D) Task of the U.S. Department of Energy's (DOE), Geothermal Technologies Office (GTO) Geothermal Vision Study (GeoVision Study). The GeoVision Study had the objective of conduc ting analyses of future geothermal growth based on sets of current and future geothermal technology developments. The RM&D Task is one of seven tasks within the GeoVision Study with the others being, Exploration and Confirmation, Potential to Penetration, Institutional Market Barriers, Environmental and Social Impacts, Thermal Applications, and Hybrid Systems. The full set of findings and the details of the GeoVision Study can be found in the final GeoVision Study report on the DOE-GTO website. As applied here, RM&D refers to the activities associated with developing, exploiting, and maintaining a known geothermal resource. It assumes that the site has already been vetted and that the resource has been evaluated to be of sufficient quality to move towards full-scale development. It also assumes that the resource is to be developed for power generation, as opposed to low-temperature or direct use applications. This document presents the key factors influencing RM&D from both a technological and operational standpoint and provides a baseline of its current state. It also looks forward to describe areas of research and development that must be pursued if the development geothermal energy is to reach its full potential.
Mechanisms of Pacific decadal variability in ESMs: the roles of stochastic forcing, feedbacks & external forcing
This project explored how and why climate patterns in the Pacific Ocean—specifically Pacific Decadal Variability (PDV)—change over time, and how well leading Earth System Models (ESMs) capture these changes under different climate scenarios. By analyzing large climate model datasets and running new simulations, the team investigated how ocean and atmosphere processes interact to shape PDV. The study tested a leading scientific hypothesis using both simplified and complex models, helping to uncover the key mechanisms that drive long-term climate swings in the Pacific. This work improves our ability to detect, predict, and understand how human-driven climate change may influence major ocean-climate patterns in the future.
Defensive Cybersecurity Architecture Design Using Force-on-Force Cyber-Physical Modeling
Currently, nuclear power plant physical security systems are highly dependent on air-gaps as a protective measure against cyber-threats. Cyber-physical threats become more likely as advanced cyber-threat capabilities to jump air-gaps transition into common use. Defending against the emerging threat of cyber-enabled physical intrusions is poorly understood. The consequence of these cyber-physical attacks has no quantitative analysis method to inform risk-informed, performance-based cybersecurity approaches. By modifying the physical security simulation tool Dante, cyber-physical threat consequence was able to be analyzed on a notional facility. The results of this analysis are used to design a Defensive Cybersecurity Architecture (DCSA) for the physical security system to produce example resilience measures for this notional facility. A DCSA defines security levels to provide a graded approach for defending plant functions, and security zones for trusted communication between systems. This approach can be applied to real world systems to produce physical protection systems and response measures that are resilient to cyber-physical threats.
POLARIZATION SIGNATURES OF RELATIVISTIC MAGNETOHYDRODYNAMIC SHOCKS IN THE BLAZAR EMISSION REGION. I. FORCE-FREE HELICAL MAGNETIC FIELDS
The optical radiation and polarization signatures in blazars are known to be highly variable during flaring activities. It is frequently argued that shocks are the main driver of the flaring events. However, the spectral variability modelings generally lack detailed considerations of the self-consistent magnetic field evolution modeling; thus, so far the associated optical polarization signatures are poorly understood. We present the first simultaneous modeling of the optical radiation and polarization signatures based on 3D magnetohydrodynamic simulations of relativistic shocks in the blazar emission environment, with the simplest physical assumptions. By comparing the results with observations, we find that shocks in a weakly magnetized environment will largely lead to significant changes in the optical polarization signatures, which are seldom seen in observations. Hence an emission region with relatively strong magnetization is preferred. In such an environment, slow shocks may produce minor flares with either erratic polarization fluctuations or considerable polarization variations, depending on the parameters; fast shocks can produce major flares with smooth polarization angle rotations. In addition, the magnetic fields in both cases are observed to actively revert to the original topology after the shocks. All these features are consistent with observations. Future observations of the radiation and polarization signatures will further constrain the flaring mechanism and the blazar emission environment.
A force balance system for the measurement of skin friction drag force in the presence of large vibrations and temperatures
Design of counterbalance system for skin friction drag measurements on hypersonic vehicles
Notes on aerodynamic forces III : the aerodynamic forces on airships
The results of the two preceding notes are applied to airships and checked with wind tunnel tests.
The origin and distribution of supersonic store interference from measurement of individual forces on several wing-fuselage-store configurations II : swept-wing-heavy-bomber configuration with large store (nacelle). lateral forces and pitching moment
Explore the source record for details and available documents.
Hydrometeorological forcing for SERVIR Climate Services (HydroSCS) — Developing a global forcing dataset to support subseasonal-to-seasonal (S2S) forecasting applications
Explore the source record for details and available documents.
On the Stability of Stochastic Parametrically Forced Equations with Rank One Forcing.
Abstract not provided.
Dante Agent Architecture for Force-On-Force Wargame Simulation and Training.
Abstract not provided.
Dante Agent Architecture for Force-On-Force Wargame Simulation and Training.
Abstract not provided.
Grain Boundary Diffusion Characterized by Atomic Force Microscopy (AFM) - Kelvin Probe Force Microscopy (KPFM).
Abstract not provided.
Advances in Nuclear Plant Physical Security Modeling and Simulation to Link Existing Nuclear Power Plant Reactor System Response, Force-on-Force Modeling, and Situational Uncertainty
Explore the source record for details and available documents.