Search results for "SIMULATION"
showing 10 items of 5095 documents
Numerical simulation of wave energy production through experimental tool
2017
Wave energy is highly desirable resource and recent international reports underline its major relevance on global renewable energy in future. In general, the first step is a correct WEC (Wave Energy Converter) sizing and design. The aim of this paper is a presentation of an application of one experimental tool to define the external floating structure of WEC realized by University of Palermo. This new electric device could be another energy possibility for small islands in the Mediterranean Sea as Pantelleria, Lampedusa or Malta.
Simulation of laser generated ultrasound with application to defect detection
2008
Laser generated ultrasound holds substantial promise for use as a tool for defect detection in remote inspection thanks to its ability to produce frequencies in the MHz range, enabling fine spatial resolution of defects. Despite the potential impact of laser generated ultrasound in many areas of science and industry, robust tools for studying the phenomenon are lacking and thus limit the design and optimization of non-destructive testing and evaluation techniques. The laser generated ultrasound propagation in complex structures is an intricate phenomenon and is extremely hard to analyze. Only simple geometries can be studied analytically. Numerical techniques found in the literature have pr…
Fast relaxation phenomena and slow mode in extended thermodynamics of superfluids
2003
A macroscopic monofluid model of liquid helium II which is based on extended thermodynamics was formulated in previous works, both in the presence and in the absence of dissipative phenomena. In all these studies, the time evolution of the nonequilibrium stress tensor was neglected, putting the relaxation times @t"0 and @t"2 of the nonequilibrium pressure and of the stress deviator equal to zero. In this work, the time evolution of these fields is not neglected and the complete model with 14 fields is studied, in the linear approximation. The propagation of waves is studied and a dispersion relation of degree 14 is obtained. The solutions of this equation are carried out, perturbing the sol…
Analysis of the depth of field of integral imaging displays based on wave optics.
2013
In this paper, we analyze the depth of field (DOF) of integral imaging displays based on wave optics. With considering the diffraction effect, we analyze the intensity distribution of light with multiple micro-lenses and derive a DOF calculation formula for integral imaging display system. We study the variations of DOF values with different system parameters. Experimental results are provided to verify the accuracy of the theoretical analysis. The analyses and experimental results presented in this paper could be beneficial for better understanding and designing of integral imaging displays.
Turing instability and traveling fronts for a nonlinear reaction–diffusion system with cross-diffusion
2012
In this work we investigate the phenomena of pattern formation and wave propagation for a reaction–diffusion system with nonlinear diffusion. We show how cross-diffusion destabilizes uniform equilibrium and is responsible for the initiation of spatial patterns. Near marginal stability, through a weakly nonlinear analysis, we are able to predict the shape and the amplitude of the pattern. For the amplitude, in the supercritical and in the subcritical case, we derive the cubic and the quintic Stuart–Landau equation respectively. When the size of the spatial domain is large, and the initial perturbation is localized, the pattern is formed sequentially and invades the whole domain as a travelin…
Considerations on the electromagnetic flow in Airy beams based on the Gouy phase
2012
We reexamine the Gouy phase in ballistic Airy beams (AiBs). A physical interpretation of our analysis is derived in terms of the local phase velocity and the Poynting vector streamlines. Recent experiments employing AiBs are consistent with our results. We provide an approach which potentially applies to any finite-energy paraxial wave field that lacks a beam axis. This research was funded by the Spanish Ministry of Economy and Competitiveness under the project TEC2009-11635.
Weakly nonlinear analysis of Turing patterns in a morphochemical model for metal growth
2015
We focus on the morphochemical reaction–diffusion model introduced in Bozzini et al. (2013) and carry out a nonlinear bifurcation analysis with the aim to characterize the shape and the amplitude of the patterns arising as the result of Turing instability of the physically relevant equilibrium. We perform a weakly nonlinear multiple scales analysis, and derive the normal form equations governing the amplitude of the patterns. These amplitude equations allow us to construct relevant solutions of the model equations and reveal the presence of multiple branches of stable solutions arising as the result of subcritical bifurcations. Hysteretic type phenomena are highlighted also through numerica…
Modeling propagation for high-power cylindrical microwave applicators
2001
In this letter, the dispersion characteristics and energy configurations of a cylindrical partially filled waveguide or lossy multilayered rod shielded by a metallic enclosure are presented for several modes. These parameters are obtained by a numerical simulation based on the residues theory. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 192–195, 2001.
Comparing the use of ERA5 reanalysis dataset and ground-based agrometeorological data under different climates and topography in Italy
2022
Study region: The study region is represented by seven irrigation districts distributed under different climate and topography conditions in Italy. Study focus: This study explores the reliability and consistency of the global ERA5 single levels and ERA5-Land reanalysis datasets in predicting the main agrometeorological estimates commonly used for crop water requirements calculation. In particular, the reanalysis data was compared, variable-by-variable (e.g., solar radiation, R; air temperature, T; relative humidity, RH; wind speed, u; reference evapotranspiration, ET), with in situ agrometeorological observations obtained from 66 automatic weather stations (2008–2020). In addition, the pre…
Trends in Research and Publication: Science 2.0 and Open Access
2009
This paper considers current trends in academic research and publication, in particular as seen from the control community. The introduction of Web 2.0 applications for scientists and engineers is currently changing the way research is being conducted. In the near future, participants in the research community will be able to share ideas, data and results like never before. They will also be able to manage the rapidly increasing amount of scientific information much more effectively than today through collaborative efforts enabled by the new Internet tools. However, an important premise for such a development is the availability of research material. Many research results are currently shie…