HEAT CONDUCTION MICRO-CALORIMETER WITH METALLIC REACTION CELL AND IMPROVED HEAT FLUX SENSING SYSTEM

2002 ◽  
Vol 30 (2) ◽  
pp. 177-186 ◽  
Author(s):  
Liliana Giraldo ◽  
Juan Carlos Moreno ◽  
Jose Ignacio Huertas
Keyword(s):  
Heat Flux ◽  
Heat Conduction ◽  
Reaction Cell ◽  
Sensing System ◽  
Micro Calorimeter

Efficient Numerical Solution of Inverse Heat Conduction Problems

1995 ◽  
Author(s):  
Hans-Jürgen Reinhardt ◽  
Dinh Nho Hao
Keyword(s):  
Heat Flux ◽  
Heat Conduction ◽  
Numerical Methods ◽  
Stationary Point ◽  
Forthcoming Paper ◽  
Inverse Heat Conduction ◽  
Piecewise Constant ◽  
Numerical Tests ◽  
Inverse Heat Conduction Problems ◽  
Special Case

Abstract In this contribution we propose new numerical methods for solving inverse heat conduction problems. The methods are constructed by considering the desired heat flux at the boundary as piecewise constant (in time) and then deriving an explicit expression for the solution of the equation for a stationary point of the minimizing functional. In a very special case the well-known Beck method is obtained. For the time being, numerical tests could not be included in this contribution but will be presented in a forthcoming paper.

A New Integral Equation for Heat Flux in Inverse Heat Conduction

1966 ◽  
Vol 88 (3) ◽  
pp. 327-328 ◽  
Author(s):  
L. I. Deverall ◽  
R. S. Channapragada
Keyword(s):  
Heat Flux ◽  
Integral Equation ◽  
Heat Conduction ◽  
Inverse Heat Conduction

Numerical Uncertainty in Heat Conduction Calculations for a Tube Immersed in a Fluidized Bed

1995 ◽  
Vol 209 (5) ◽  
pp. 323-336 ◽  
Author(s):  
A I Karamavruc ◽  
N N Clark ◽  
I Celik
Keyword(s):  
Heat Flux ◽  
Heat Conduction ◽  
Horizontal Tube ◽  
Numerical Code ◽  
Uniform Grid ◽  
Grid Refinement ◽  
Transfer Coefficients ◽  
Parabolic Profile ◽  
Grid Convergence ◽  
Spatial Domains

A numerical code has been evaluated with regard to numerical uncertainties involved in calculating heat flux through the wall of a horizontal tube in a bubbling bed of sand. The two-dimensional unsteady heat conduction equation is solved numerically with a non-linearly varying temperature boundary condition prescribed according to measurements. The finite difference method used is an implicit method with a second-order accurate discretization scheme both in temporal and spatial domains. Previous literature dealing with numerical calculations in heat conduction usually reports any detailed study about numerical errors. In the present analysis, a rigorous grid dependence test is applied, and it is shown that the results, in particular heat flux, are very sensitive to the grid size and distribution. Therefore, to achieve better grid convergence when heat flux is sought, the discretization error in the heat flux rather than in the temperature calculations should be considered. This should be done even in cases where temperature is the primary unknown, because it is usually the derivative of temperature which is of any physical importance. The errors are also strongly dependent on the number of iterations which need to be increased as the grid is refined. The present application showed that a non-uniform grid refinement throughout the calculation domain gives a more efficient (less expensive) solution than uniform grid refinement. Furthermore, for calculation of the temperature gradient at the wall, a parabolic profile assumption gives a faster grid convergence compared to a linear profile assumption. The present study shows that the previously published results concerning calculated heat transfer coefficients should be interpreted with caution, unless the authors have provided some measure of grid dependency of their results.

Finite Element Formulation for Two-Dimensional Inverse Heat Conduction Analysis

1992 ◽  
Vol 114 (3) ◽  
pp. 553-557 ◽  
Author(s):  
T. R. Hsu ◽  
N. S. Sun ◽  
G. G. Chen ◽  
Z. L. Gong
Keyword(s):  
Heat Flux ◽  
Finite Element ◽  
Heat Conduction ◽  
Surface Heat Flux ◽  
Surface Heat ◽  
Element Formulation ◽  
Two Dimensional ◽  
Inverse Heat Conduction ◽  
Discrete Point ◽  
Element Algorithm

This paper presents a finite element algorithm for two-dimensional nonlinear inverse heat conduction analysis. The proposed method is capable of handling both unknown surface heat flux and unknown surface temperature of solids using temperature histories measured at a few discrete point. The proposed algorithms were used in the study of the thermofracture behavior of leaking pipelines with experimental verifications.

scholarly journals Optimization of Geometric Parameters of Thermal Insulation of Pre-Insulated Double Pipes

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1012 ◽  
Author(s):  
Dorota Krawczyk ◽  
Tomasz Teleszewski
Keyword(s):  
Heat Flux ◽  
Heat Conduction ◽  
Cross Section ◽  
Thermal Insulation ◽  
Major Axis ◽  
Heat Losses ◽  
Sectional Area ◽  
Cross Sectional ◽  
Elliptical Shape ◽  
Half Axis

This paper presents the analysis of the heat conduction of pre-insulated double ducts and the optimization of the shape of thermal insulation by applying an elliptical shape. The shape of the cross-section of the thermal insulation is significantly affected by the thermal efficiency of double pre-insulated networks. The thickness of the insulation from the external side of the supply and return pipes affects the heat losses of the double pre-insulated pipes, while the distance between the supply and return pipes influences the heat flux exchanged between these ducts. An assumed elliptical shape with a ratio of the major axis to the minor half axis of an ellipse equaling 1.93 was compared to thermal circular insulation with the same cross-sectional area. All calculations were made using the boundary element method (BEM) using a proprietary computer program written in Fortran as part of the VIPSKILLS project.

scholarly journals Time-Fractional Heat Conduction in a Plane with Two External Half-Infinite Line Slits under Heat Flux Loading

Symmetry ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 689 ◽  
Author(s):  
Yuriy Povstenko ◽  
Tamara Kyrylych
Keyword(s):  
Heat Flux ◽  
Heat Conduction ◽  
Heat Conduction Equation ◽  
Graphical Representation ◽  
Integral Transform ◽  
Conduction Equation ◽  
Infinite Plane ◽  
Conservation Of Energy ◽  
Infinite Line ◽  
Fractional Heat Conduction

The time-fractional heat conduction equation follows from the law of conservation of energy and the corresponding time-nonlocal extension of the Fourier law with the “long-tail” power kernel. The time-fractional heat conduction equation with the Caputo derivative is solved for an infinite plane with two external half-infinite slits with the prescribed heat flux across their surfaces. The integral transform technique is used. The solution is obtained in the form of integrals with integrand being the Mittag–Leffler function. A graphical representation of numerical results is given.

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