Моделювання задач теплового неруйнівного контролю з використанням комп'ютерних технологій

Пропонується використання пакету прикладних програм COMSOL Multiphysics для дослідження процесів теплового неруйнівного контролю. Показані можливості цього пакету при вирішенні задачі теплового неруйнівного контролю на прикладі двомірної моделі об’єкта контролю. Отримані результати дослідження підтверджують можливість використання пакету прикладних програм COMSOL Multiphysics для моделювання різних задач теплового неруйнівного контролю різних об’єктів контролю.Предлагается использование пакета прикладных программ COMSOL Multiphysics для исследования процессов теплового неразрушающего контроля. Показаны возможности этого пакета при решении задачи теплового неразрушающего контроля на примере двухмерной модели объекта контроля. Полученные результаты исследования подтверждают возможность использования пакета прикладных программ COMSOL Multiphysics для моделирования различных задач теплового неразрушающего контроля различных объектов контроля.It is proposed to use application package COMSOL Multiphysics to study the processes of thermal nondestructive testing. The possibilities of this package in solving the problem of thermal NDT for example a two-dimensional model of the object of control. These studies confirm the results of the use of application package COMSOL Multiphysics for modeling various tasks thermal nondestructive testing of different control objects

Heat transfer simulation of evacuated tube collectors (ETC): An application to a prototype

Since fossil fuels shortages are predicted for the forthcoming generations, the use of renewable energy sources is playing a key role and is strongly recommended worldwide by national and international regulations. In this scenario, solar collectors for hot water preparation, space heating and cooling are becoming an increasingly interesting alternative, especially in the building sector because of population growth. Thus, the present paper is addressed to numerically investigate the thermal behaviour of a prototypal evacuated tube by solving the heat transfer differential equations using the Finite Element Method. This is to reproduce the heat transfer process occurring within the real system, helping the industry improve the prototype

Computing directivity patterns in Comsol Multiphysics

Bakalářská práce na téma Výpočet směrových charakteristik antén v programu Comsol Multiphysics. V první části jsou představeny základní teoretické pojmy. Druhá část je věnována analýze několika druhů antén programem COMSOL Multiphysics a výpočtu jejich směrových charakteristik a vstupních impedancí. V třetí části jsou souhrnně zpracovány změřená a vypočtená data.The individual project – Computing directivity patterns in Comsol Multiphysics. In the first part, the theoretical background for monopole antennas is reviewed. The second part is focused on the analysis of several types of monopoles in COMSOL Multiphysics, and on the calculation of their radiation patterns and impedances. Finally, simulation results are presented and discussed.

Multiphysics Finite\u2013Element Modelling of an All\u2013Vanadium Redox Flow Battery for Stationary Energy Storage

All-Vanadium Redox Flow Batteries (VRFBs) are emerging as a novel technology for stationary energy storage. Numerical models are useful for exploring the potential performance of such devices, optimizing the structure and operating condition of cell stacks, and studying its interfacing to the electrical grid. A one-dimensional steady-state multiphysics model of a single VRFB, including mass, charge and momentum transport and conservation, and coupled to a kinetic model for electrochemical reactions, is first presented. This model is then extended, including reservoir equations, in order to simulate the VRFB charge and discharge dynamics. These multiphysics models are discretized by the finite element method in a commercial software package (COMSOL). Numerical results of both static and dynamic 1D models are compared to those from 2D models, with the same parameters, showing good agreement. This motivates the use of reduced models for a more efficient system simulation

Numerical simulation of drying of Pinus pseudostrobus wood with Comsol Multiphysics

In this work, we present the second part of our investigation. In the first part, we have published a semi-empirical model for drying. In this second part, we present the numerical solution of a drying model for Pinus pseudostrobus (Mexican softwood). The model take into account a multiphysics approach. The model describes the moisture mobilities and profiles. The system of partial differential equations were solved in COMSOL 3.4 with the UMFPACK solver. Three primary variables are solved; the moisture content; the temperature; and the density of dry air. The model is validated by comparison. We have compared the phenomenological model versus experimental data and versus a semiempirical model

The Actuator Design and the Experimental Tests of a New Technology Large Deformable Mirror for Visible Wavelengths Adaptive Optics

Recently, Adaptive Secondary Mirrors showed excellent on-sky results in the Near Infrared wavelengths. They currently provide 30mm inter-actuator spacing and about 1 kHz bandwidth. Pushing these devices to be operated at visible wavelengths is a challenging task. Compared to the current systems, working in the infrared, the more demanding requirements are the higher spatial resolution and the greater correction bandwidth. In fact, the turbulence scale is shorter and the parameter variation is faster. Typically, the former is not larger than 25 mm (projected on the secondary mirror) and the latter is 2 kHz, therefore the actuator has to be more slender and faster than the current ones. With a soft magnetic composite core, a dual-stator and a single-mover, VRALA, the actuator discussed in this paper, attains unprecedented performances with a negligible thermal impact. Pre-shaping the current required to deliver a given stroke greatly simplifies the control system, whose output supplies the current generator. As the inductance depends on the mover position, the electronics of this generator, provided with an inductance measure circuit, works also as a displacement sensor, supplying the control system with an accurate feed-back signal. A preliminary prototype, built according to the several FEA thermo-magnetic analyses, has undergone some preliminary laboratory tests. The results of these checks, matching the design results in terms of power and force, show that the the magnetic design addresses the severe specifications