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Comparison of methods for solving the heat transfer in electrical machines

Makki Z., Janda M., Deeb R.

Poznan University of Technology Academic Journals. Electrical Engineering

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2013

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No. 75

25--31

EN

This paper describes the use of modern computational methods for the verification of mathematical equations, to determine the total heat flow transmitted across a certain surface. ANSYS WORKBENCH is choosen as the computational software for this purpose. Calculations are presented for four models. There is a surface, which the total heat flow is transmitted through is considered as: a simple flat plate, comprising with other flat plate, and thin-walled and thick-walled tube. For each case, the total heat flow is calculated using numerical methods and modem computer methods (ANSYS WORBENCH). Performed results of numerical methods are compared with the results of ANSYS software. The numerical methods are considered as a referent. The error of ANSYS calculations in comparison with the the numerical is calculated. The heat transfer by conduction is described for all presented models. Finally, the results of temperature distribution and heat flux distribution for each simulated case are presented.

2

The problem with flow in radial channels synchronous machine

Makki Z., Janda M., Deeb R.

Poznan University of Technology Academic Journals. Electrical Engineering

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2012

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No. 72

75--82

EN

This paper describes the use of computational methods for solving the flow of the air-cooling in the large synchronous machines where it is used to cool the stator winding and stator radial channels which are located between the stator packet sheets. The overall process flow is mostly influenced by the size of air gap between stator and rotor, the shape of the radial channels, and by flow rates in machines. This paper mostly discusses about the influence flow rate of the cooling medium which has effects on the pressure distribution and flow rate in the radial channels. Cooling medium considered in this article an air and for and for calculation was chosen ANSYS CFX.

3

Optimization of fan of induction motor in the Ansys Workbench

Janda M., Makki Z., Deeb R.

Poznan University of Technology Academic Journals. Electrical Engineering

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2012

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No. 72

141--147

EN

This paper deals with the optimization of cooling of electric machines using Ansys Workbench. In many areas of electrical machines are increasingly used optimization methods to achieve greater performance and improved efficiency of the individual parts of electrical machines. These methods are very often connecting to computer programs such as Ansys, in order to obtain the best results. The program Ansys Workbench is several optimization algorithms that can be connected to the analysis of any group of physical fields. This allows other programs without the need to achieve optimal results in the design of electrical machines. This article specifically addresses the application of these algorithms for the adaptation of design changes the fan induction motor. Optimization was used to size the fan blades to achieve the greatest possible pressure coolant. The main dimensions of this design are limited fan induction motor and therefore are not optimized. The article discussed the results of this optimization, and also summarizes the main advantages and disadvantages of using this procedure.

4

Comparison of 2D and 3D FEM analysis of the magnetic field in a PM servo motor

Deeb R., Janda M., Makki Z.

Poznan University of Technology Academic Journals. Electrical Engineering

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2012

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No. 72

297--309

EN

Nowadays, the applications of the electrical machines with permanent magnets become very common, because of the outstanding properties of these devices in comparison with the induction machines. PM machines do not indicate electrical losses with the field excitation, which means increasing of their efficiency. This is a very important factor considering the urgent need of the energy conservation. Although, numerical methods for a field computation are time consuming, they provide accurate results without making any simplification of the geometry. The paper presents a comparison of 2D and 3D magnetic analysis of a PM servo motor. The analyzed servo motor is designed with a surface magnet rotor and produced by the VUES Brno company. The applied PM material is of rare earth type NdFeB. This material is characterized by a very high energy product. 2D model of this servo motor is created using AutoCAD program. The 2D magnetic analysis is computed using FEMM (finite element method magnetics). The 3D magnetic analysis is computed using a modem technique in the field of magnetic analysis of electrical machines. 3D model of the servo motor is generated using RMxprt program. The 3D magnetic analysis of the generated 3D model is computed using Maxwell 3D program. The program Maxwell 3D generates fine mesh automatically with a high accuracy. The distribution of the magnetic field inside the servo motor is computed for the case of the nominal current in both of 2D and 3D magnetic analysis. The distribution of the magnetic flux density according to the air gap length is presented too. The FEM (finite element method) is used for both 2D and 3D magnetic analysis of this servo motor.