Geometric Reconstruction Of Cement Microstructure Image Based On Edge Response Scattering Points Extraction And MLS

High loads and bearing life requirements make journal bearings a potential choice for use in high power, epicyclic gearboxes in jet engines. Particularly in a planetary configuration the kinematic conditions are complex. With the planet gears rotating about their own axis and orbiting around the sun gear, centrifugal forces generated by both motions interact with each other and affect the external flow behavior of the oil exiting the journal bearing. Computational Fluid Dynamics (CFD) simulations using the Volume of Fluid (VoF) method are carried out in ANSYS Fluent [1] to numerically model the two-phase flow behavior of the oil exiting the bearing and merging into the air surrounding the bearing. This paper presents an investigation of two numerical schemes that are available in ANSYS Fluent to track or capture the air-oil phase interface: the geometric reconstruction scheme and the compressive scheme. Both numerical schemes are used to model the oil outflow behavior in the most simplistic approximation of a journal bearing: a representation, rotating about its own axis, with a circumferentially constant, i.e. concentric, lubricating gap. Based on these simplifications, a three dimensional (3D) CFD sector model with rotationally periodic boundaries is considered. A comparison of the geometric reconstruction scheme and the compressive scheme is presented with regards to the accuracy of the phase interface reconstruction and the time required to reach steady state flow field conditions. The CFD predictions are validated against existing literature data with respect to the flow regime, the direction of the predicted oil flow path and the oil film thickness. Based on the findings and considerations of industrial requirements, a recommendation is made for the most suitable scheme to be used. With a robust and partially validated CFD model in place, the model fidelity can be enhanced to include journal bearing eccentricity. Due to the convergent-divergent gap and the resultant pressure field within the lubricating oil film, the outflow behavior can be expected to be very different compared to that of a concentric journal bearing. Naturally, the inlet boundary conditions for the oil emerging from the journal bearing into the external environment must be consistent with the outlet conditions from the bearing. The second part of this paper therefore focuses on providing a method to generate appropriate inlet boundary conditions for external oil flow from an eccentric journal bearing.

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CT image quality influence on different material Edge Response Functions for accurate metrological applications

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1193/1/012064 ◽

2021 ◽

Vol 1193 (1) ◽

pp. 012064

Author(s):

I Holgado ◽

J Iglesias ◽

N Ortega ◽

S Plaza ◽

A Pascual

Keyword(s):

Image Quality ◽

Spot Size ◽

Ct Measurements ◽

Aluminium Copper ◽

Measurement Results ◽

X Ray Computed ◽

Ct Image Quality ◽

The Relationship ◽

Ct Measurement ◽

Edge Response

Abstract The main objective of the proposed work was to analyse the influence of magnification and focal spot size scan settings on X-ray computed tomography (CT) measurements results under commercial threshold-based algorithms. The relationship between spatial resolution and contrast sensitivity in CT scans of different materials and the accuracy of the resulting CT measurement results is discussed. For that purpose, Aluminium, Copper, Inconel 718 and Titanium disk phantoms were scanned. Preliminary measurements showed that deviations can increase up to 0.48% when the scanning magnification was increased while, for a given magnification, the decrease of a focus size from 1mm to 0.4mm slightly improves the differences up to 0.15%, being negligible at low magnifications. Unsharpness (U T ) and contrast-to-noise ratio (CNR) were calculated for each scanning conditions according to standard ASTM E1695 – 20. A new image quality indicator that includes the combined effect of the U T and CNR was proposed in order to relate measurement error with the image quality. The indicator proves that the influence of CNR is much higher than influence of U T on the CT measurements.

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Restauración paisajística de Cantera Rosales. Hellín (Albacete, España)

REVISTARQUIS ◽

10.15517/ra.v5i2.27160 ◽

2016 ◽

Vol 5 (2) ◽

Author(s):

José Durán Fernández ◽

Daniel Moreno Ruiz

Keyword(s):

Design Methodology ◽

Mining Activity ◽

Land Art ◽

Innovative Design ◽

Ornamental Stone ◽

Geometric Reconstruction ◽

Man And Nature ◽

The Impact ◽

Near Future ◽

The Relationship

ResumenEl texto describe y dibuja una estrategia de recuperación ecológica de una explotación minera de piedra ornamental en activo, situada en el entorno del parque arqueológico del Tolmo de Minateda, en el Término municipal de Hellín (Albacete, España). En el año 2015, la empresa Areniscas Rosal, propietaria de los derechos de explotación de dicha cantera, encargó a la oficina de Arquitectura y Urbanismo SSS (Spanish Studio of Space) un Plan de Restauración para establecer las directrices básicas de una recuperación paisajística que revierta el impacto de la actividad extractiva en un futuro próximo. El proyecto, fundamentado en la filosofía del Land Art, es una reconstrucción geométrica del terreno por medio de la reutilización de los sobrantes de la propia actividad, para así crear un paisaje totalmente nuevo y contemporáneo. El reciclaje, la re-vegetación y una solución proyectual innovadora fundamentan las directrices de esta intervención paisajística y territorial. Las posibilidades de reutilización y disfrute de este nuevo entorno natural podrán ser variadas y enriquecedoras y solo dependerán de una gestión sensible y respetuosa de la relación del hombre con la naturaleza. AbstractThe former document describes and draws a strategy of ecological recovery of an ornamental stone mine in active, located in the archaeological park environment of Tolmo de Minateda in the municipality of Hellín (Albacete, Spain). Back in 2015, the company Rosal Sandstones, which owns the rights to exploit the quarry, commissioned the Office of Architecture and Urbanism SSS (Spanish Studio of Space) a Restoration Plan in order to establish the basic guidelines for a landscape recovery to revert the impact of mining activity in the near future. The project, based on the philosophy of Land Art, is a geometric reconstruction of the ground by means of reusing the leftovers of the activity itself, to thereby create a totally new and contemporary landscape. Recycling, re-vegetation and innovative design methodology solutions substantiate the guidelines of this landscape and territorial intervention. The possibilities for reusability and enjoyment of this new natural environment can be diverse and enriching and, only depend on a sensitive and respectful management of the relationship between man and nature.

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ICE DETECTION ON AIRPLANE WINGS USING A PHOTOGRAMMETRIC POINT CLOUD: A SIMULATION

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xliii-b2-2020-183-2020 ◽

2020 ◽

Vol XLIII-B2-2020 ◽

pp. 183-189

Author(s):

I. Aicardi ◽

A. Lingua ◽

L. Mazzara ◽

M. A. Musci ◽

G. Rizzo

Keyword(s):

Point Cloud ◽

Processing Time ◽

Field Testing ◽

Reference Surface ◽

Steel Panel ◽

Final Configuration ◽

Geometric Reconstruction ◽

Sensor Technique ◽

Ice Detection ◽

Hyperspectral Sensor

Abstract. This study describes some tests carried out, within the European project (reference call: MANUNET III 2018, project code: MNET18/ICT-3438) called SEI (Spectral Evidence of ice), for the geometrical ice detection on airplane wings. The purpose of these analysis is to estimate thickness and shape of the ice that an RGB sensor is able to detect on large aircrafts as Boeing 737-800. However, field testing are not available yet, therefore, in order to simulate the final configuration, a steel panel has been used to reproduce the aircraft surface. The adopted methodology consists in defining a reference surface and modelling its 3D shape with and without ice through photogrammetric acquisitions collected by a DJI Mavic Air drone hosting a RGB camera and processed by Agisoft Metashape software. The comparison among models with and without the ice has been presented and results show that it is possible to identify the ice, even though some noise still remains due to the geometric reconstruction itself. Finally, using 3dReshaper and Matlab software, the authors develop various analysis defining the operative limits, the processing time, the correct setting up of Metashape for a more accurate ice detection, the optimization of the methodology in terms of processing time, precision and completeness. The procedure can certainly be more reliable considering the usage of the hyperspectral sensor technique as future implementation.

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