An Inverse Method for Controlling the Temperature Distribution and Identification of the Conductivity of Thick Cylindrical Shells

2011 ◽  
Author(s):  
Hossein Rastgoftar ◽  
Faissal A. Moslehy
Keyword(s):  
Temperature Distribution ◽  
Heat Conduction Equation ◽  
Inverse Method ◽  
Cylindrical Shells ◽  
Three Dimensional ◽  
Heat Fluxes ◽  
Heat Diffusion ◽  
The Finite Element Method ◽  
Steady State Heat ◽  
Boundary Surfaces

The paper presents an inverse method for control of temperature distribution in thick cylindrical shells. Since the thickness is large enough, three-dimensional heat diffusion equations must be considered. To control the temperature distribution, the heat fluxes at the boundary surfaces of the cylindrical shell are assigned values such that the desired temperature distribution, which satisfies the steady state heat conduction equation, will be achieved. Furthermore, a Lyapunov-based method for identification of the conductivity of the cylinder is presented, and the estimated conductivity is updated such that it converges to the exact value. The numerical results are obtained by the finite element method (FEM), which include the heat flux at the surfaces of the cylinder. These results are shown to be in excellent agreement with the analytical solution.

scholarly journals An approximate analytic solution of a particular boundary value problem

2001 ◽  
Vol 27 (8) ◽  
pp. 513-520
Author(s):  
Ugur Tanriver ◽  
Aravinda Kar
Keyword(s):  
Boundary Value Problem ◽  
Heat Conduction Equation ◽  
Analytic Solution ◽  
Boundary Value ◽  
Three Dimensional ◽  
Welding Process ◽  
Approximate Analytic Solution ◽  
Analytic Expression ◽  
Steady State Heat ◽  
Laser Welding Process

This note is concerned with the three-dimensional quasi-steady-state heat conduction equation subject to certain boundary conditions in the wholex′y′-plane and finite inz′-direction. This type of boundary value problem arises in laser welding process. The solution to this problem can be represented by an integral using Fourier analysis. This integral is approximated to obtain a simple analytic expression for the temperature distribution.

Experimental Measurements of Temperature Distribution in Three Dimensional Stacked Package

2007 ◽  
Author(s):  
Anand Desai ◽  
James Geer ◽  
Bahgat Sammakia
Keyword(s):  
Experimental Study ◽  
Heat Conduction ◽  
Steady State ◽  
Temperature Distribution ◽  
Numerical Model ◽  
Analytical Solution ◽  
Three Dimensional ◽  
Power Input ◽  
Experimental Measurements ◽  
Steady State Heat

This paper presents the results of an experimental study of steady state heat conduction in a three dimensional stack package. The temperatures are measured at different interfaces within the stacked package. Delphi devices are used in the experiment which enables controlled power input and surface temperature of the devices. The experiment is carried out for three different boundary conditions on the package. The power input in varied to study its effects. A numerical model is created to compare to the experimental results. The results are also compared with the analytical solution presented in Desai et al [5] and Geer et al [6]. The results indicate that the experimental, numerical and analytical solutions follow the same trend. The agreement between the experimental and numerical results improves when the lateral losses are taken into account.

scholarly journals Analyses of Effects of Cutting Parameters on Cutting Edge Temperature Using Inverse Heat Conduction Technique

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Marcelo Ribeiro dos Santos ◽  
Sandro Metrevelle Marcondes de Lima e Silva ◽  
Álisson Rocha Machado ◽  
Márcio Bacci da Silva ◽  
Gilmar Guimarães ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
High Speed Steel ◽  
Cutting Parameters ◽  
Heat Fluxes ◽  
Cutting Edge ◽  
Heat Diffusion ◽  
Numerical Code ◽  
Heat Diffusion Equation ◽  
Specification Method ◽  
Edge Temperature

During machining energy is transformed into heat due to plastic deformation of the workpiece surface and friction between tool and workpiece. High temperatures are generated in the region of the cutting edge, which have a very important influence on wear rate of the cutting tool and on tool life. This work proposes the estimation of heat flux at the chip-tool interface using inverse techniques. Factors which influence the temperature distribution at the AISI M32C high speed steel tool rake face during machining of a ABNT 12L14 steel workpiece were also investigated. The temperature distribution was predicted using finite volume elements. A transient 3D numerical code using irregular and nonstaggered mesh was developed to solve the nonlinear heat diffusion equation. To validate the software, experimental tests were made. The inverse problem was solved using the function specification method. Heat fluxes at the tool-workpiece interface were estimated using inverse problems techniques and experimental temperatures. Tests were performed to study the effect of cutting parameters on cutting edge temperature. The results were compared with those of the tool-work thermocouple technique and a fair agreement was obtained.

Thermal Math Modeling and Analysis of an Electronic Assembly

2000 ◽  
Vol 123 (4) ◽  
pp. 372-378 ◽  
Author(s):  
K. N. Shukla
Keyword(s):  
Temperature Distribution ◽  
Integral Transform ◽  
Three Dimensional ◽  
Thermal Characteristics ◽  
Circuit Board ◽  
Heat Sources ◽  
The Finite Element Method ◽  
Modeling And Analysis ◽  
Discrete Surface ◽  
Integral Transform Technique

This paper presents a mathematical model for a three-dimensional thermal analysis of a circuit board with multiple heat dissipating sources. The model considers the three-dimensional flat plate with discrete surface heat sources and integral transform technique is employed to determine the temperature distribution. The calculation procedure for the thermal characteristics of a circuit board, with surface mounted components, is presented and the solution is compared with those obtained from the finite element method. Also, the temperature distribution of a two-layered circuit board is presented in terms of Green’s function.

SEMINUMERICAL MODEL TO STUDY TEMPERATURE DISTRIBUTION IN PERIPHERAL LAYERS OF ELLIPTICAL AND TAPERED SHAPED HUMAN LIMBS

2010 ◽  
Vol 10 (01) ◽  
pp. 57-72 ◽  
Author(s):  
MAMTA AGRAWAL ◽  
NEERU ADLAKHA ◽  
KAMALRAJ PARDASANI
Keyword(s):  
Temperature Distribution ◽  
Three Dimensional ◽  
Axial Direction ◽  
Temperature Profiles ◽  
Series Method ◽  
The Finite Element Method ◽  
Biophysical Parameters ◽  
Metabolic Heat ◽  
Metabolic Heat Generation ◽  
Fourier Series Method

In this article, a seminumerical approach has been developed to study temperature distribution in peripheral layers of tapered shaped human limbs, which are elliptical in shape. The model is three-dimensional which incorporates the important biophysical parameters such as blood mass flow rate, thermal conductivity and rate of metabolic heat generation. Appropriate boundary conditions have been framed using biophysical conditions. The finite element method has been employed along radial and angular directions and Fourier series method along axial direction to obtain temperature profiles in the region. The results have been used to study relationships among various physical and physiological parameters. MATLAB 7.0 has been used to simulate the model and obtain numerical results.

A Three-Dimensional Thermal-Mechanical Asperity Contact Model for Two Nominally Flat Surfaces in Contact

2000 ◽  
Vol 123 (3) ◽  
pp. 595-602 ◽  
Author(s):  
Geng Liu ◽  
Qian Wang ◽  
Shuangbiao Liu
Keyword(s):  
Frictional Heating ◽  
Three Dimensional ◽  
Contact Model ◽  
Asperity Contact ◽  
The Finite Element Method ◽  
Flat Surfaces ◽  
Solution Methods ◽  
Steady State Heat ◽  
Steady State Heat Transfer ◽  
Rough Surface Contact

The rough surface contact in a tribological process involves frictional heating and thermoelastic deformations. A three-dimensional thermal-mechanical asperity contact model has been developed, which takes into account steady-state heat transfer, asperity distortion due to thermal and elastic deformations, and material yield. The finite-element method (FEM), fast Fourier transform (FFT), and conjugate gradient method (CGM) are employed as the solution methods. The model is used to analyze the thermal-mechanical contact of typical rough surfaces and investigate the importance of thermal effects on the contact performance of surface asperities.

A Numerical Model to Determine Temperature Distribution in Aluminum Alloy (2A12) Micro-Cutting

2011 ◽  
Vol 175 ◽  
pp. 330-334
Author(s):  
Tao Guo ◽  
Guang Chen ◽  
Cheng Zu Ren
Keyword(s):  
Aluminum Alloy ◽  
Temperature Distribution ◽  
Heat Source ◽  
Heat Diffusion ◽  
Analysis Model ◽  
Workpiece Material ◽  
Heat Diffusion Equation ◽  
Micro Cutting ◽  
Process Effects ◽  
Steady State Heat

Heat generation during cutting process affects the machined workpiece material and influences the cutting forces and tool wear. In this paper, a static thermal analysis model is developed to determine temperature rise in aluminum alloy (2A12) micro-cutting. The modified model is established based on two-dimensional steady state heat diffusion equation along with heat losses by convection film coefficients at the surfaces. A negative heat source is applied to simulate the heat loss during chip formation process. Effects of chip length and negative heat source on temperature distribution are discussed. The simulation results are compared with experiment data. The final results indicated that the model with negative heat source is more accurate than that without negative heat source and 20mm chip length give best temperature field fitting to the experiment.

scholarly journals Numerical modeling of heat flow between three-dimensional regions in contact problems

2018 ◽  
Vol 157 ◽  
pp. 08010
Author(s):  
Tomasz Skrzypczak ◽  
Ewa Węgrzyn-Skrzypczak
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Numerical Modeling ◽  
Three Dimensional ◽  
Contact Problems ◽  
Heat Transfer Process ◽  
Heat Diffusion ◽  
The Finite Element Method ◽  
Three Dimensional Objects ◽  
The Mathematical Model

The method of numerical modeling of heat transfer between three-dimensional objects being in contact is described in the paper. Presented approach is based on the finite element method (FEM) with independent spatial discretization of considered regions. The gap between external surfaces of the interacting objects has variable width and is filled with gas or liquid. The medium in the gap introduces thermal resistance into heat transfer process. The mathematical model of considered problem is based on the equation of heat diffusion supplemented by the appropriate initial and boundary conditions. The deformations of the regions resulting from the thermally dependent changes of their volumes are also included in the model. The results of numerical simulations are presented and discussed.

Comparison of Conventional and Pontic Fixed Partial Dentures Over Implants Using the Finite Element Method: Three-Dimensional Analysis of Cortical and Medullary Bone Stress

2020 ◽  
Vol 46 (3) ◽  
pp. 175-181
Author(s):  
Marcelo Bighetti Toniollo ◽  
Mikaelly dos Santos Sá ◽  
Fernanda Pereira Silva ◽  
Giselle Rodrigues Reis ◽  
Ana Paula Macedo ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Medullary Bone ◽  
Principal Stresses ◽  
Bone Stress ◽  
Bone Damage ◽  
Rehabilitation System ◽  
Minimum Requirements

Rehabilitation with implant prostheses in posterior areas requires the maximum number of possible implants due to the greater masticatory load of the region. However, the necessary minimum requirements are not always present in full. This project analyzed the minimum principal stresses (TMiP, representative of the compressive stress) to the friable structures, specifically the vestibular face of the cortical bone and the vestibular and internal/lingual face of the medullary bone. The experimental groups were as follows: the regular splinted group (GR), with a conventional infrastructure on 3 regular-length Morse taper implants (4 × 11 mm); and the regular pontic group (GP), with a pontic infrastructure on 2 regular-length Morse taper implants (4 × 11 mm). The results showed that the TMiP of the cortical and medullary bones were greater for the GP in regions surrounding the implants (especially in the cervical and apical areas of the same region) but they did not reach bone damage levels, at least under the loads applied in this study. It was concluded that greater stress observed in the GP demonstrates greater fragility with this modality of rehabilitation; this should draw the professional's attention to possible biomechanical implications. Whenever possible, professionals should give preference to use of a greater number of implants in the rehabilitation system, with a focus on preserving the supporting tissue with the generation of less intense stresses.

Towards Predicting Relative Belt Edge Endurance With the Finite Element Method

1990 ◽  
Vol 18 (4) ◽  
pp. 216-235 ◽  
Author(s):  
J. De Eskinazi ◽  
K. Ishihara ◽  
H. Volk ◽  
T. C. Warholic
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Shear Deformations ◽  
Element Analysis ◽  
Vertical Loading ◽  
Predicted Values ◽  
Element Method

Abstract The paper describes the intention of the authors to determine whether it is possible to predict relative belt edge endurance for radial passenger car tires using the finite element method. Three groups of tires with different belt edge configurations were tested on a fleet test in an attempt to validate predictions from the finite element results. A two-dimensional, axisymmetric finite element analysis was first used to determine if the results from such an analysis, with emphasis on the shear deformations between the belts, could be used to predict a relative ranking for belt edge endurance. It is shown that such an analysis can lead to erroneous conclusions. A three-dimensional analysis in which tires are modeled under free rotation and static vertical loading was performed next. This approach resulted in an improvement in the quality of the correlations. The differences in the predicted values of various stress analysis parameters for the three belt edge configurations are studied and their implication on predicting belt edge endurance is discussed.

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