HYPERBOLIC HEAT CONDUCTION ANALYSIS FOR AN ORTHOTROPIC FG HOLLOW SPHERE WITH INTERNAL HEAT SOURCE. APPLICATION OF A NEW AUGMENTED STATE SPACE METHOD

2017 ◽  
Vol 48 (15) ◽  
pp. 1399-1419
Author(s):  
Majid Bakhtiari ◽  
K. Daneshjou ◽  
H. Parsania ◽  
M. Fakoor
2016 ◽  
Vol 138 (12) ◽  
Author(s):  
M. Bakhtiari ◽  
K. Daneshjou ◽  
R. Alibakhshi

In the present research, a new and straightforward mathematical model, named augmented state-space method, is introduced to solve the heat conduction equation for a multilayered orthotropic hollow cylinder with bonding imperfection in the presence of heat source. Since such problems including heat source are inherently inhomogeneous and complex, augmented state-space method converts these inhomogeneous equations into homogeneous ones. The transient solution will be achieved by present method based on laminate approximation theory in the Laplace domain, and then the solutions obtained are retrieved into the time domain by applying the numerical Laplace transform inversion. All material properties can be considered to vary continuously within the cylinder along the radial direction with arbitrary grading pattern. Based on the proposed method, the solution of heat conduction problem can be also obtained for general boundary conditions which may be included various combinations of arbitrary temperature, flux, or convection. Due to lack of any data on the transient thermal analysis corresponding to problems with imperfect bonds in the cylindrical coordinate system (r,θ), comparison is carried out with the available results for the three-layer semi-circular annular region with perfect bonds in the literature. Finally, the influence of orthotropy and interface imperfection on the distribution of the temperature field for three-layer hollow cylinder, in which the second layer is made of orthotropic functionally graded material (FGM), will be visualized.


2004 ◽  
Vol 04 (04) ◽  
pp. 435-445 ◽  
Author(s):  
SHUICHI TORII ◽  
WEN-JEI YANG

A numerical study is performed on the effect of laser radiation on the propagation phenomenon of a thermal wave in a very thin film subjected to a symmetrical heating on both sides. Laser heating is modelled as an internal heat source. The non-Fourier, hyperbolic heat conduction equation is solved by a numerical technique based on MacCormack's predictor-corrector scheme. Consideration is given to the time history of heat transfer behaviour before and after symmetrical collision of wave fronts from two sides of a film. It is disclosed that (i) if the absorption coefficient of the laser increases, temperature overshoot causes in a very thin film within a very short period of time, and (ii) the overshoot and oscillation of thermal wave depend on the frequency of the heat source time characteristics. This trend becomes minor in a thick film.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Renu Yadav ◽  
Kapil Kumar Kalkal ◽  
Sunita Deswal

The theory of generalized thermoelasticity with fractional order strain is employed to study the problem of one-dimensional disturbances in a viscoelastic solid in the presence of a moving internal heat source and subjected to a mechanical load. The problem is in the context of Green-Naghdi theory of thermoelasticity with energy dissipation. Laplace transform and state space techniques are used to obtain the general solution for a set of boundary conditions. To tackle the expression of heat source, Fourier transform is also employed. The expressions for different field parameters such as displacement, stress, thermodynamical temperature, and conductive temperature in the physical domain are derived by the application of numerical inversion technique. The effects of fractional order strain, two-temperature parameter, viscosity, and velocity of internal heat source on the field variables are depicted graphically for copper material. Some special cases of interest have also been presented.


2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Eugeniusz Zieniuk ◽  
Dominik Sawicki

The most popular methods used for solving transient heat conduction problems, like finite element method (FEM) and boundary element method (BEM), require discretization of the domain or the boundary. The discretization problem escalates for unsteady issues, because an iterative process is required to solve them. An alternative to avoid the mentioned problem is parametric integral equations systems (PIESs), which do not require classical discretization of the boundary and the domain, while being numerically solved. PIES have been previously used with success to solve steady-state problems. Moreover, they have been recently tested also with success for transient heat conduction problems, without internal heat sources. The purpose of this paper is to generalize PIES based on analytical modification of classical boundary integral equation (BIE) for transient heat conduction with internal heat source and nonuniform rational basis spline (NURBS) for boundary modeling. The obtained generalization of PIES is tested on examples, mostly with defined exact solution.


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