scholarly journals Transient thermal regime trough the constitutive matrix applied to asynchronous electrical machine using the cell method

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 717-726 ◽  
Author(s):  
Pablo Ignacio González-Domínguez ◽  
José Miguel Monzón-Verona ◽  
Santiago García-Alonso
Keyword(s):  
Thermal Regime ◽  
Thermal Conduction ◽  
Equation System ◽  
Electrical Machine ◽  
Cell Method ◽  
Differential Formulation ◽  
Transient Thermal ◽  
Thermal Phenomena ◽  
Physical Laws ◽  
Constitutive Matrix

Abstract In this paper, a new constitutive matrix for thermal conduction in transient thermal regime is developed and tested. We use cell method as a numerical method that is included in finite formulation methodology. The constitutive matrix defines through the cell method the behavior of solids when they are under a thermal potential. We have demonstrated that this matrix is equivalent to the electrical conduction constitutive matrix in steady state. We have applied this constitutive matrix to thermal analysis of asynchronous electric machines in transient regime. This constitutive matrix has been validated with comparisons based on finite element method. In finite formulation, the physical laws governing the electromagnetic fields and the physical thermal phenomena are expressed in integral formulation. The final algebraic equation system is tailored directly without discretizing of the differential equations. This is an important advantage because we omit a complex differential formulation and the discretization of the respective equations.

scholarly journals New Thermal-Conductivity Constitutive Matrix in Fourier’s Law for Heat Transfer Using the Cell Method

2019 ◽  
Vol 9 (21) ◽  
pp. 4521
Author(s):  
González-Domínguez ◽  
Monzón-Verona ◽  
García-Alonso
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Finite Element Method ◽  
Thermal Conduction ◽  
Computational Method ◽  
The Finite Element Method ◽  
Cell Method ◽  
Tetrahedral Meshes ◽  
The Matrix ◽  
Constitutive Matrix

In this paper, a new constitutive matrix Mτ for thermal conduction, for tetrahedral meshes, in a steady state thermal regime is developed through a new algebraic methodology, using the Cell Method as a computational method, which is included in the finite formulation. The constitutive matrix defines the behavior of solids when they are under a thermal potential. The results are compared with those obtained for the same problem by means of the constitutive matrix Mλ developed previously, taking in both cases with a 2D axisymmetric model as reference, calculated with the finite element method. The errors obtained with the new matrix Mτ are of the order of 0.0025%, much lower than those obtained with the matrix Mλ.

scholarly journals Thermal constitutive matrix applied to asynchronous electrical machine using the cell method

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 27-30 ◽  
Author(s):  
Pablo Ignacio González Domínguez ◽  
José Miguel Monzón-Verona ◽  
Leopoldo Simón Rodríguez ◽  
Adrián de Pablo Sánchez
Keyword(s):  
Heat Conduction ◽  
Internal Heat ◽  
Conduction Equation ◽  
Equivalent Model ◽  
Electrical Machine ◽  
Heat Sources ◽  
Conduction Model ◽  
Cell Method ◽  
Internal Heat Sources ◽  
Constitutive Matrix

Abstract This work demonstrates the equivalence of two constitutive equations. One is used in Fourier’s law of the heat conduction equation, the other in electric conduction equation; both are based on the numerical Cell Method, using the Finite Formulation (FF-CM). A 3-D pure heat conduction model is proposed. The temperatures are in steady state and there are no internal heat sources. The obtained results are compared with an equivalent model developed using the Finite Elements Method (FEM). The particular case of 2-D was also studied. The errors produced are not significant at less than 0.2%. The number of nodes is the number of the unknowns and equations to resolve. There is no significant gain in precision with increasing density of the mesh.

scholarly journals Transient thermal conduction with variable conductivity using the Meshless Local Petrov–Galerkin method

2016 ◽  
Vol 272 ◽  
pp. 676-686 ◽  
Author(s):  
N.P. Karagiannakis ◽  
G.C. Bourantas ◽  
A.N. Kalarakis ◽  
E.D. Skouras ◽  
V.N. Burganos
Keyword(s):  
Galerkin Method ◽  
Thermal Conduction ◽  
Transient Thermal ◽  
Variable Conductivity

scholarly journals The influence of water percolation through crevasses on the thermal regime of a Himalayan mountain glacier

2020 ◽  
Vol 14 (4) ◽  
pp. 1273-1288 ◽  
Author(s):  
Adrien Gilbert ◽  
Anna Sinisalo ◽  
Tika R. Gurung ◽  
Koji Fujita ◽  
Sudan B. Maharjan ◽  
...  
Keyword(s):  
Thermal Regime ◽  
Simple Method ◽  
Mountain Glacier ◽  
Basal Ice ◽  
Water Percolation ◽  
Influence Of Water ◽  
Mechanical Models ◽  
Himalayan Mountain ◽  
Ground Penetrating ◽  
Transient Thermal

Abstract. In cold and arid climates, small glaciers with cold accumulation zones are often thought to be entirely cold based. However, scattering in ground-penetrating radar (GPR) measurements on the Rikha Samba Glacier in the Nepal Himalayas suggests a large amount of temperate ice that seems to be influenced by the presence of crevassed areas. We used a coupled thermo-mechanical model forced by a firn model accounting for firn heating to interpret the observed thermal regime. Using a simple energy conservation approach, we show that the addition of water percolation and refreezing in crevassed areas explains these observations. Model experiments show that both steady and transient thermal regimes are significantly affected by latent heat release in crevassed areas. This makes half of the glacier base temperate, resulting in an ice dynamic mainly controlled by basal friction instead of ice deformation. The timescale of thermal regime change, in response to atmospheric warming, is also greatly diminished, with a potential switch from cold to temperate basal ice in 50–60 years in the upper part of the glacier instead of the 100–150 years that it would take without the effect of the crevasses. This study highlights the crucial role of water percolation through the crevasses on the thermal regime of glaciers and validates a simple method to account for it in glacier thermo-mechanical models.

Integrated Thermal Conduction and Hardenability Laboratory Activity

2013 ◽  
Author(s):  
Natasha L. Smith ◽  
Brandon S. Field
Keyword(s):  
Heat Transfer ◽  
Thermal Conduction ◽  
Machine Design ◽  
Engineering Curriculum ◽  
Laboratory Activity ◽  
One Dimensional ◽  
Practical Applications ◽  
Transformation Curve ◽  
Transient Thermal ◽  
Quench Test

This paper describes an integrated laboratory project between separate heat transfer and machine design courses. The project was structured around a Jominy end quench hardenability test. Most of the students participating were simultaneously enrolled in both classes. In the heat transfer class, students were required to model one-dimensional, transient thermal conduction for an end quench geometry of 4140 steel. In machine design, students applied their theoretical temperature profiles to a continuous cooling transformation curve (CCT) of 4140 steel to predict microstructure and matched the theoretical cooling rates with hardenability curves from literature to predict hardness. In laboratory, students then performed an end quench test in accordance with ASTM A255 on four steel rods. By combining activities across the two courses, students developed an appreciation for the interconnectivity of material within the engineering curriculum, and learned that practical applications typically require they employ knowledge from a variety of sources.

Comparison of transient thermal conduction in tellurium and organic dye based digital optical storage media

1987 ◽  
Vol 61 (1) ◽  
pp. 74-80 ◽  
Author(s):  
A. N. Burgess ◽  
K. E. Evans ◽  
M. Mackay ◽  
S. J. Abbott
Keyword(s):  
Thermal Conduction ◽  
Optical Storage ◽  
Organic Dye ◽  
Storage Media ◽  
Transient Thermal

A DIRECT DISCRETE FORMULATION FOR THE WAVE EQUATION

2001 ◽  
Vol 09 (04) ◽  
pp. 1355-1382 ◽  
Author(s):  
ENZO TONTI
Keyword(s):  
Wave Equation ◽  
Close Link ◽  
Cell Complexes ◽  
Global Variables ◽  
Differential Formulation ◽  
D’Alembert Equation ◽  
Physical Laws ◽  
Discrete Formulation ◽  
Preliminary Classification

The paper shows how to give a direct discrete formulation of the wave equation starting directly from physical laws, i.e. without passing through differential formulation. Using global variables instead of scalar and vector field functions, a close link between global variables and spatial and temporal elements immediately appears. A preliminary classification of physical variables into three classes: configuration, source and energy variables and the use of two cell complexes, one dual of the other, gives an unambiguous association of global variables to the spatial and temporal elements of the two complexes. Thus, one arrives at a discrete formulation of d'Alembert equation on an unstructured mesh.

scholarly journals The hierarchical finite cell method for nonlinear problems: Moment fitting quadratures, basis function removel, and remeshing

2021 ◽  
Author(s):  
Simeon Hubrich
Keyword(s):  
Basis Function ◽  
Large Deformations ◽  
Nonlinear Problems ◽  
Equation System ◽  
Integration Process ◽  
Finite Cell Method ◽  
Cell Method ◽  
Strain Measures ◽  
Finite Cell ◽  
Goal And Scope

In this thesis, several approaches are discussed in order to further enhance the performance of the finite cell method (FCM). Thereby, novel moment fitting quadrature schemes are introduced that allow to reduce the effort of the numerical integration process significantly. Further, a basis function removal scheme is proposed to improve the conditioning behavior of the resulting equation system. Finally, an innovative remeshing strategy is presented that overcomes the problem of severely distorted elements for simulations with large deformations. Contents 1 Introduction 1 1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Goal and scope of this thesis . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 Outline of this thesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2 Basic elements of continuum mechanics 6 2.1 Kinematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.1.1 Motion and deformation . . . . . . . . . . . . . . . . . . . . . . . . 6 2.1.2 Strain measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.2 Equilibrium and stress measures . . . . . . . . ....

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