International Journal of Applied Electromagnetics and Mechanics - Volume 31, issue 3

Authors: Yang, Enhui | Mo, Jinqiu | Liu, Handan | Xu, Wei | Wang, Shigang

Article Type: Research Article

Abstract: The disposal of interface conditions is a key problem for the application of meshless method in numerical computation of engineering electromagnetic field. Due to the meshless methods employing moving least square approximation scheme can not verify the Kronecker-δ property, the interface conditions can not be enforced automatically as done in FEM. This paper applies methods based on the modification of the weak form, such as Lagrange multiplier method and penalty method, to impose electromagnetic field interface …conditions. Using above methods, the general models of electromagnetic field interface conditions expressed by A-φ-A approach are implemented by using the element-free Galerkin method. Then, a rectangular cross section solenoid with analytical solution is employed to validate the effect of the imposition of electromagnetic field interface conditions, and discuss the potential problems when using above two methods in different cases. Show more

Keywords: Electromagnetic field, interface conditions, element-free Galerkin method, Lagrange multiplier method, penalty method

DOI: 10.3233/JAE-2009-1051

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 31, no. 3, pp. 127-145, 2009

Authors: Yang, Enhui | Wang, Xinhong | Mo, Jinqiu | Cao, Jiayong | Wang, Shigang

Article Type: Research Article

Abstract: Streamline upwinding approach combining meshless method is proposed to model electromagnetic field involving moving component. And the detailed implementation of streamline upwinding meshless method is completed for A-φ-A formulation of electromagnetic field. Different numerical examples show that streamline upwinding approach can suppress effectively the numerical oscillation contained in meshless method solution of electromagnetic field involving moving component.

Keywords: Electromagnetic field, meshless method, streamline upwinding, moving component, numerical oscillation

DOI: 10.3233/JAE-2009-1055

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 31, no. 3, pp. 147-160, 2009

Authors: Marčič, Tine | Štumberger, Bojan | Štumberger, Gorazd | Hadiselimović, Miralem | Zagradišnik, Ivan

Article Type: Research Article

Abstract: The comparison of electromechanical characteristics of a 4-pole and a 6-pole induction motor with 36 stator slots in combination with 28, 33, 34, 44 and 46 rotor slots is presented. A comparative analysis is performed by evaluating: the iron losses at no-load, the shapes of torque-slip curves, the shapes of torque per unit current vs. slip curves, and the efficiencies and over-temperatures in thermal equilibrium at rated load. The paper evidently shows that motors which exhibited …low values of iron losses at no-load also exhibited superior line-starting performance, high values of torque per unit stator current and superior efficiency at rated load. Moreover, the paper shows the feasibility of using the same stator and rotor slot combination for a mid-size 4-pole and 6-pole induction motor. Show more

Keywords: Induction motors, drives, stator and rotor slot combinations, electromechanical characteristics, measurements

DOI: 10.3233/JAE-2009-1053

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 31, no. 3, pp. 161-169, 2009

Authors: Losito, Onofrio | Cinquepalmi, Luca

Article Type: Research Article

Abstract: The growing use of metal foams in electromagnetic applications such as shielding applications, has paved the way to develop a simple analytical 3D model of metal foams, as discussed in this paper, considering the electromagnetic behaviour of an equivalent double wire-mesh screens model, separated by an air space. The good results encourages to design a metal foam shields with this model.

DOI: 10.3233/JAE-2009-1054

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 31, no. 3, pp. 171-180, 2009

Authors: Ho, S.L. | Yang, Shiyou

Article Type: Research Article

Abstract: Based on the metaphor of the foraging mechanism of honey bee swarms as well as on available works, an artificial bee colony algorithm is proposed for solving difficult inverse electromagnetic problems. In the proposed algorithm, the entire searching process is divided into an intensification and a diversification phase. For intensification searches, some novel formulas are proposed for the employed bees and onlookers to carry out exploiting searches around specific memorized food sources; and scouts are used …to generate new food sources to guarantee the diversity of the algorithm in diversification searches. Also, an age variable is introduced to measure the "exhausted" level of a food source and then decide when to abandon a memorized food source. Three numerical examples are reported to validate the robustness and to demonstrate the advantages of the proposed algorithm. Show more

Keywords: Bee colony algorithm, evolutionary programming, inverse problem, swarm intelligence

DOI: 10.3233/JAE-2009-1056

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 31, no. 3, pp. 181-192, 2009