Search results for "Aeronautics"
showing 10 items of 148 documents
Thermal Analysis of the Solar Orbiter PHI Electronics Unit
2020
“© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.”
Initial layout of DEMO buildings and configuration of the main plant systems
2018
Abstract The realization of a Demonstration Fusion Power Reactor (DEMO) to follow ITER, with the capability of generating several hundred MW of net electricity and operating with a closed fuel-cycle is viewed by Europe and many of the nations engaged in the construction of ITER as the remaining crucial step towards the exploitation of fusion power. The development of suitable configurations of plant systems inside the tokamak building to allow for the various maintenance operations and to meet the numerous system operating functions and safety requirements is one of the initial priorities. A task to establish an initial layout of the DEMO buildings and the integration of the main plant syst…
Conversion of Existing Roundabouts into Turbo-Roundabouts: Case Studies from Real World
2012
Compared with roundabouts the main advantages of turbo-roundabouts are the reduction in the number of potential conflicting points and the lower speed of vehicles passing through the intersection, they both can improve safety conditions at the junction. Moreover, the physical delimitation among lanes limits the side-by-side accident risk. These aspects make turbo-roundabouts more appropriate than roundabouts when a higher level of safety has to be guaranteed, particularly in presence of relevant pedestrian and two-wheels traffic volumes. The present paper has three main objectives: (1) to discuss general design criteria and functional principles of turbo roundabouts, (2) to give the geometr…
Boundary-layer Flows Past an Hemispherical Roughness Element: DNS, Global Stability and Sensitivity Analysis
2015
Abstract We investigate the full three-dimensional instability mechanism arising in the wake of an hemispherical roughness element immersed in a laminar Blasius boundary layer. The inherent three-dimensional flow pattern beyond the critical Reynolds number is characterized by coherent vortical structures called hairpin vortices. Direct numerical simulation is used to analyze the formation and the shedding of hairpin packets inside the shear layer. The first bifurcation characteristics are investigated by global stability tools. We show the spatial structure of the linear direct and adjoint global eigenmodes of the linearized Navier-Stokes operator and use structural sensitivity analysis to …
On-Road Study of Fatigue Management Strategies in Long-Haul Truck Drivers
2014
The current study investigated what strategies long-haul truck drivers use to mitigate fatigue at the wheel. A group of 52 truck drivers participated in the study in which drivers’ fatigue at the wheel was measured by a well-validated self-rating scale (the Karolinska Sleepiness Scale) and the use of fatigue countermeasures by a diary for a period of two consecutive workweeks including day and night-time trips. Results showed that the drivers more frequently used fatigue countermeasures while fatigued at the wheel but most of these countermeasures, with the exception of caffeine, can be regarded as inefficient (e.g., opening a window). The results indicate that long-haul truck drivers resp…
Driver Situation Awareness and Perceived Sleepiness during Truck Platoon Driving–Insights from Eye-tracking Data
2021
Truck platoon driving technology uses vehicle-to-vehicle communication to allow one truck to follow another in an automated fashion. The first vehicle is operated manually, the second vehicle is dr...
Passenger Car Equivalent for Heavy Vehicles Crossing Turbo-roundabouts
2016
Abstract Turbo-roundabouts represent an innovative scheme of modern roundabouts which provides a spiraling traffic flow and requires drivers to choose their direction before entering the intersection, since raised lane separators mark the lanes on the ring. The configuration of the turbo-roundabout makes that patterns of conflict at entries with one and two conflicting traffic streams can coexist. This paper presents research efforts aimed at measuring quantitatively the effect of heavy vehicles on operational conditions of a turbo-roundabout. The study starts from the initial belief that the greatest constraints to the vehicular trajectories imposed by the turbo-roundabout necessarily impl…
The effect of cooperative infrastructure fees on high-speed rail and airline competition
2021
Abstract This paper explores the effects of cooperation between rail and air infrastructures in setting per-passenger fees prior to competition among airlines and high-speed rail (HSR) in a transport network. It is shown that, for a sufficiently low degree of substitution, cooperation results in lower fees and greater HSR traffic than under competition. Besides, it leads to more connecting passengers. An empirical application allows for a quantitative assessment of cooperation. Gains to passengers and operators are sizeable when cooperation either involves all infrastructure managers or the rail and the hub airport managers. Welfare gains are in the range of 10.4–11.1%. Our contribution off…
A Computational Approach to Vibration Control of Vehicle Engine-Body Systems
2012
In recent years, the noise and vibration of cars have become increasingly important [20, 23, 29, 30, 35]. A major comfort aspect is the transmission of engine-induced vibrations through powertrain mounts into the chassis (see Figure 1). Engine and powertrain mounts are usually designed according to criteria that incorporate a trade-off between the isolation of the engine from the chassis and the restriction of engine movements. The engine mount is an efficient passive means to isolate the car chassis structure from the engine vibration. However, the passive means for isolation is efficient only in the high frequency range. However the vibration disturbance generated by the engine occurs mai…
An Aircraft Pilot Workload Sensing System
2021
The workload evaluation is of great importance for human error avoidance training, particularly in the use of complex systems that requires different and concurrent activities. The excessive workload harms human performance even with adverse outcomes. In the aviation field, certain flight maneuvers, such as take-off and landing, are characterized by great attention and workload demand to the pilot. Thus, a system capable of measuring pilots’ workload levels during flight could be beneficial to increase pilots’ performance. This work aims to study the initial feasibility of a device called Cockpit Pilot Warning System that monitors the pilot workload level during flight. With this aim, an ex…