Search results for " Flux"
showing 10 items of 583 documents
Prediction of friction and heat flow in machining incorporating thermophysical properties of the coating–chip interface
2004
Abstract This paper deals with an experimental and analytical investigation into the thermodynamically activated effects influencing the behaviour of the multi-layered coated tool rake face during orthogonal cutting of ferromagnetic and paramagnetic steels. Temperature measurements on the tool rake face using a thermocouple-based technique and identification of the contact zone by means of computer image processing were carried out. New methodology for assessing friction and the amount of thermal energy generated when machining with a coated tool insert with natural and restricted contact coupled with a metallic chip, using thermophysical properties of the sliding materials is developed in …
Determination of temperature distribution in the cutting zone using hybrid analytical-FEM technique
2006
Abstract In this study, the temperature distribution in the cutting zone was determined by integrating thermal analytical and simulation models of orthogonal cutting process with uncoated and coated carbide tools. Primarily, 2D FEM simulations were run to provide numerical solutions of temperatures occurring at different points through the chip/tool contact region and the coating/substrate boundary under defined cutting conditions. In addition, an analytical model for heat transfer in the cutting tool and its partitioning, proposed in References [W. Grzesik, P. Nieslony, Physics based modelling of interface temperatures in machining with multilayer coated tools at moderate cutting speeds, I…
The effect of manufacturing tolerances on a tubular linear ferrite motor
2015
This study presents a numerical and experimental study on the effect of permanent magnet tolerances on the performances of a Tubular Linear Ferrite Motor. The statistical distribution of the magnetic characteristic of a set of commercial magnets is obtained experimentally while the performances of a the tubular motor are numerically evaluated. The performances that have been considered are: cogging force, end effect force and generated thrust. It has been shown that: 1)the statistical variability of the magnets modifies the time behavior of the cogging force; 2)the value of both the end effect cogging force and the generated thrust are directly linked to the values of then remanence field o…
GA-based Off-Line Parameter Estimation of the Induction Motor Model Including Magnetic Saturation and Iron Losses
2020
This paper, starting from recent papers in the scientific literature dealing with Rotating Induction Motor (RIM) dynamic modelling, as a first step, improves its space-vector dynamic model, including both the magnetic saturation and iron losses; The main original aspects of the proposed model are the following: 1) the magnetic saturation of the iron core has been described on the basis of both current versus flux and flux versus current functions, 3) it includes the iron losses, separating them in hysteresis and eddy current ones, 4) it includes the effect of the load on the magnetic saturation. Afterwards, it proposes an off-line technique for the estimation of electrical parameters of thi…
Design optimization for the adoption of bonded magnets in PM BLDC motors
2014
The increment of the manageable power in machines where the normally adopted ferrites are replaced with bonded magnets can vary and can introduce saturation problems depending on the variations in the magnetic circuit design. The saturation of the magnetic circuit distorts the phase voltages, introducing undesired harmonics in the connection to the mains. Combined modifications of both stator poles and rotor ring of a Brushless DC motor are proposed to evaluate their impact on the increment of the manageable power and on the harmonic content. Several magnetic circuit modifications have been considered and the paper presents the results of the most reasonable solutions, obtaining significant…
Intensive wave power and steel quenching 3-D model for cylindrical sample. Time direct and reverse formulations and solutions
2017
In this paper we develop mathematical models for three dimensional hyperbolic heat equations (wave equation or telegraph equation) with inner source power and construct their analytical solutions for the determination of the initial heat flux for cylindrical sample. As additional conditions the temperature and heat flux at the end time are given. In some cases we give expression of wave energy. In some cases we give expression of wave energy. Some solutions of time inverse problems are obtained in the form of first kind Fredholm integral equation, but others has been obtained in closed analytical form as series. We viewed both direct and inverse problems at the time. For the time inverse pr…
ROTOR FLUX OPTIMAL ESTIMATION FOR INDUCTION MOTOR CONTROL
2005
Abstract The aim of this paper is to analyze and design reduced order observers of the rotor flux of induction motors. The design requirements are: a) the convergence rate of the rotor flux estimation error; b) a low sensitivity to stator and rotor resistance variations; c) a low sensitivity to errors due to the implementation of the observers on microprocessor-based systems. It is shown that, in order to satisfy the requirements a)-c), it is sufficient to solve a constrained optimization problem according to a criterion in which these requirements appear explicitly. The implementation of the observer is discussed. The observer is tested by simulation and experiments.
Design, manufacturing and testing of a fast disconnecting system for the European target assembly concept of IFMIF
2013
The International Fusion Materials Irradiation Facility (IFMIF) will be equipped with a lithium target assembly to produce the required neutron flux for the irradiation of candidate fusion materials up to a damage rate of 100 dpa (cumulated damage in five years). The present European target assembly design is based on the so called replaceable backplate bayonet concept that was developed with the objective to simplify the maintenance operations for its refurbishment/replacement and to reduce the material for disposal as well. To this purpose it was also conceived to be attached to the lithium pipes and to the beam line by means of remotely operated connections based on clamped flanges with …
Thermal characterization of insulating materials
2018
Abstract The strict energy saving standards are based on the declared values of the materials, i.e. U-value, thermal conductivity or thermal capacity. To this end, proper knowledge of the thermophysical properties of the wall components is needed, especially with regard to new lightweight technologies that are being used in building construction/refurbishment, under the dynamic conditions of the Mediterranean climate, where one of most important parameters of building materials is their heat capacity because of the influence of solar radiation energy. With this regard, the actual heat capacity value, obtained in laboratory tests, is typically quite different from the nominal one. So, this p…
A small scale prototype of a wave energy conversion system for hydrogen production
2015
In this paper a small scale prototype of sea wave energy converter for hydrogen production and storage is presented. Laboratory prototypes of the wave energy converter device and sea water electrolyzer are presented. Experimental results are shown. A cost-effective and efficient power electronics system is designed. Experimental waveforms of the wave energy converter are imported in the power electronics simulation model to simulate the whole system as closely as possible to its effective behavior. Simulation results are shown to test the efficiency of the proposed solution.