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A Aziz - One of the best experts on this subject based on the ideXlab platform.

  • an improved approximate method for determining the temperature and Efficiency of the nonlinear convective radiative generating Fin effect of environmental temperatures
    Heat and Mass Transfer, 2015
    Co-Authors: M. N. Bouaziz, A Aziz
    Abstract:

    Efficiency and temperature distributions of rectangular convective-radiative-generating Fin are evaluated when thermal conductivity and internal heat generation are temperature dependent. It demonstrates that the proposed method can be treated sequentially the nonlinear Fin problem with three nonlinearities. Predicted results are found accurate within 4 % of the tip Fin temperature and 5 % for the efficiencies. For practical used Fins, the Fin Efficiency is strongly sensitive to convective and radiation environmental temperatures.

  • a least squares method for a longitudinal Fin with temperature dependent internal heat generation and thermal conductivity
    Energy Conversion and Management, 2011
    Co-Authors: A Aziz, M. N. Bouaziz
    Abstract:

    Approximate but highly accurate solutions for the temperature distribution, Fin Efficiency, and optimum Fin parameter for a constant area longitudinal Fin with temperature dependent internal heat generation and thermal conductivity are derived analytically. The method of least squares recently used by the authors is applied to treat the two nonlinearities, one associated with the temperature dependent internal heat generation and the other due to temperature dependent thermal conductivity. The solution is built from the classical solution for a Fin with uniform internal heat generation and constant thermal conductivity. The results are presented graphically and compared with the direct numerical solutions. The analytical solutions retain their accuracy (within 1% of the numerical solution) even when there is a 60% increase in thermal conductivity and internal heat generation at the base temperature from their corresponding values at the sink temperature. The present solution is simple (involves hyperbolic functions only) compared with the fairly complex approximate solutions based on the homotopy perturbation method, variational iteration method, and the double series regular perturbation method and offers high accuracy. The simple analytical expressions for the temperature distribution, the Fin Efficiency and the optimum Fin parameter are convenient for use by engineers dealing with the design and analysis of heat generating Fins operating with a large temperature difference between the base and the environment.

  • simple and accurate solution for convective radiative Fin with temperature dependent thermal conductivity using double optimal linearization
    Energy Conversion and Management, 2010
    Co-Authors: M. N. Bouaziz, A Aziz
    Abstract:

    Abstract A novel concept of double optimal linearization is introduced and used to obtain a simple and accurate solution for the temperature distribution in a straight rectangular convective–radiative Fin with temperature dependent thermal conductivity. The solution is built from the classical solution for a pure convection Fin of constant thermal conductivity which appears in terms of hyperbolic functions. When compared with the direct numerical solution, the double optimally linearized solution is found to be accurate within 4% for a range of radiation–conduction and thermal conductivity parameters that are likely to be encountered in practice. The present solution is simple and offers superior accuracy compared with the fairly complex approximate solutions based on the homotopy perturbation method, variational iteration method, and the double series regular perturbation method. The Fin Efficiency expression resembles the classical result for the constant thermal conductivity convecting Fin. The present results are easily usable by the practicing engineers in their thermal design and analysis work involving Fins.

  • thermal analysis of a longitudinal trapezoidal Fin with temperature dependent thermal conductivity and heat transfer coefficient
    Communications in Nonlinear Science and Numerical Simulation, 2010
    Co-Authors: F Khani, A Aziz
    Abstract:

    Abstract A homotopy analysis method (HAM) is used to develop analytical solution for the thermal performance of a straight Fin of trapezoidal profile when both the thermal conductivity and the heat transfer coefficient are temperature dependent. Results are presented for the temperature distribution, heat transfer rate, and Fin Efficiency for a range of values of parameters appearing in the mathematical model. Since the HAM algorithm contains a parameter that controls the convergence and accuracy of the solution, its results can be verified internally by calculating the residual error. The HAM results were also found to be accurate to at least three places of decimal compared with the direct numerical solution of the mathematical model generated using a fourth–fifth-order Runge–Kutta–Fehlberg method. The HAM solution appears in terms of algebraic expressions which are not only easy to compute but also give highly accurate results covering a wide range of values of the parameters rather than the small values dictated by the perturbation solution.

D D Ganji - One of the best experts on this subject based on the ideXlab platform.

  • investigation of refrigeration Efficiency for fully wet circular porous Fins with variable sections by combined heat and mass transfer analysis
    International Journal of Refrigeration-revue Internationale Du Froid, 2014
    Co-Authors: M Hatami, D D Ganji
    Abstract:

    Abstract Temperature distribution equation and refrigeration Efficiency for fully wet circular porous Fins with variable sections are introduced in this study by a new modified wet Fin parameter presented by Sharqawy and Zubair. This parameter can be calculated without knowing the Fin tip condition by considering the temperature and humidity ratio differences for the driving forces of heat and mass transfer, respectively. It's assumed that heat and mass convective coefficients vary with Fin temperature and heat transfer through porous media is simulated using passage velocity from the Darcy's model. After presenting the governing equation, Least Square Method (LSM) and fourth order Runge-Kutta method (NUM) are applied for predicting the temperature distribution in the sample aluminum porous Fins. After that, effects of porosity, Darcy number, Rayleigh number, Lewis number and etc. on Fin Efficiency are examined. As a main outcome, for reaching to high values of Fin Efficiency, rectangular Fin should be used instead of convex and triangular sections.

  • approximate solution of the nonlinear heat transfer equation of a Fin with the power law temperature dependent thermal conductivity and heat transfer coefficient
    Propulsion and Power Research, 2014
    Co-Authors: S Mosayebidorcheh, D D Ganji, Masoud Farzinpoor
    Abstract:

    Abstract In this paper, differential transform method (DTM) is used to solve the nonlinear heat transfer equation of a Fin with the power-law temperature-dependent both thermal conductivity and heat transfer coefficient. Using DTM, the differential equation and the related boundary conditions transformed into a recurrence set of equations and Finally, the coefficients of power series are obtained based on the solution of this set of equations. DTM overcame on nonlinearity without using restrictive assumptions or linearization. Results are presented for the dimensionless temperature distribution and Fin Efficiency for different values of the problem parameters. DTM results are compared with special case of the problem that has an exact closed-form solution, and an excellent accuracy is observed.

  • determining the Fin Efficiency of convective straight Fins with temperature dependent thermal conductivity by using homotopy perturbation method
    International Journal of Numerical Methods for Heat & Fluid Flow, 2012
    Co-Authors: D D Ganji, M Rahimi, M Rahgoshay
    Abstract:

    Purpose – The purpose of this paper is to determine the Fin Efficiency of convective straight Fins with temperature dependent thermal conductivity by using Homotopy Perturbation Method.Design/methodology/approach – Most engineering problems, especially heat transfer equations are in nonlinear form. Homotopy Perturbation Method (HPM) has been applied to solve a wide series of nonlinear differential equations. In this paper, HPM is used for obtaining the Fin Efficiency of convective straight Fins with temperature‐dependent thermal conductivity. Comparison of the results with those of Homotopy Perturbation Method, exact solution, numerical results and Adomian's decomposition method (ADM) were been done by Cihat Arslanturk.Findings – Results show that both Homotopy Perturbation Method and ADM applied to the nonlinear equations were capable of solving them with successive rapidly convergent approximations without any restrictive assumptions or transformations causing changes in the physical properties of the p...

  • analytical and numerical investigation of Fin Efficiency and temperature distribution of conductive convective and radiative straight Fins
    Heat Transfer Research, 2011
    Co-Authors: D D Ganji, M Rahimi, M Rahgoshay, M Jafari
    Abstract:

    In this study, Fin Efficiency, temperature distribution, and effectiveness of conductive, convective, and radiative straight Fins with temperature dependent thermal conductivity are solved using the differential transformation method (DTM).The concept of differential transformation is briefly introduced, and then it is employed to derive the solutions of nonlinear governing equations of Fins with highly nonlinear terms because of existing radiation in this study. The obtained results of DTM are compared with those of the Galerkin method (GM) and numerical boundary value problem method (BVP) to verify the accuracy of the proposed method. Furthermore, the effects of some physical appropriate parameters such as thermo-geometric Fin parameters and thermal parameters are analyzed. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.20341

  • differential transformation method to determine Fin Efficiency of convective straight Fins with temperature dependent thermal conductivity
    International Communications in Heat and Mass Transfer, 2009
    Co-Authors: A A Joneidi, D D Ganji, M Babaelahi
    Abstract:

    In this study, Fin Efficiency of convective straight Fins with temperature-dependent thermal conductivity is solved using a simulation method called the Differential Transformation Method (DTM). The concept of differential transformation is briefly introduced, and then we employed it to derive solutions of nonlinear equation. The obtained results from DTM are compared with those from the exact and numerical solution to verify the accuracy of the proposed method. The results reveal that the Differential Transformation Method can achieve suitable results in predicting the solution of such problems. After this verification, we analyze the effects of some physical applicable parameters in this problem such as thermo-geometric Fin parameter and thermal conductivity parameter.

M. N. Bouaziz - One of the best experts on this subject based on the ideXlab platform.

Cihat Arslanturk - One of the best experts on this subject based on the ideXlab platform.

  • optimum design of space radiators with temperature dependent thermal conductivity
    Applied Thermal Engineering, 2006
    Co-Authors: Cihat Arslanturk
    Abstract:

    Radiating extended surfaces are widely used to enhance heat transfer between primary surface and the environment. The performance of such a surface is significantly affected by variable thermal conductivity, particularly in the case of large temperature differences. In this paper, the Adomian decomposition method is used to evaluate the Efficiency of a radiating rectangular Fin with variable thermal conductivity. Because the resulting complicated Fin Efficiency expression is not convenient for further optimization calculations, the data from the present solutions is correlated for a suitable range of problem parameters. The correlation equations are used to Find the optimum dimensions of space radiators which maximize the heat transfer rate per unit radiator mass. The optimization results are conveniently represented as two identical correlation equations for calculating the optimum dimensions.

  • a decomposition method for Fin Efficiency of convective straight Fins with temperature dependent thermal conductivity
    International Communications in Heat and Mass Transfer, 2005
    Co-Authors: Cihat Arslanturk
    Abstract:

    Abstract The Adomian decomposition method (ADM) has been used to evaluate the Efficiency of straight Fins with temperature-dependent thermal conductivity and to determine the temperature distribution within the Fin. The method is useful and practical for solving the nonlinear heat diffusion equation, which is associated with variable thermal conductivity condition. The ADM provides an analytical solution in the form of an inFinite power series. The Fin Efficiency of the straight Fins with temperature-dependent thermal conductivity has been obtained as a function of thermo-geometric Fin parameter and the thermal conductivity parameter describing the variation of the thermal conductivity. It has been observed that the thermal conductivity parameter has a strong influence over the Fin Efficiency. The data from the present solutions has been correlated for a wide range of thermo-geometric Fin parameter and the thermal conductivity parameter. The resulting correlation equations can assist thermal design engineers for designing of straight Fins with temperature-dependent thermal conductivity.

Syed M. Zubair - One of the best experts on this subject based on the ideXlab platform.

  • Heat and mass transfer from annular Fins of different cross-sectional area. Part I. Temperature distribution and Fin Efficiency
    International Journal of Refrigeration-revue Internationale Du Froid, 2012
    Co-Authors: Mostafa H. Sharqawy, Abdurrahman Moinuddin, Syed M. Zubair
    Abstract:

    Abstract A numerical analysis is carried out to study Efficiency and temperature distribution of annular Fins of different Fin profiles (constant and variable cross-sectional area) when subjected to simultaneous heat and mass transfer mechanisms. The temperature and humidity ratio differences are driving forces for heat and mass transfer, respectively. Actual psychrometric relations are used in the present work instead of a linear model between humidity ratio and temperature that has been used in the literature. A non-linear model representing heat and mass transfer mechanisms was solved using a Finite difference successive over-relaxation method. Solutions are obtained for temperature distribution over the Fin surface in addition to Fin Efficiency for both fully wet and partially wet Fin surfaces. The numerical results are compared with those of previous studies. It was found that one of the linear models for the relation between the humidity ratio and temperature is a reasonable approximation.

  • thermal analysis and optimization of orthotropic pin Fins a closed form analytical solution
    Journal of Heat Transfer-transactions of The Asme, 2010
    Co-Authors: Syed M. Zubair, A F M Arif, Mostafa H. Sharqawy
    Abstract:

    Analytical solutions for temperature distribution, heat transfer rate, and Fin Efficiency and Fin effectiveness are derived and presented for orthotropic two-dimensional pin Fins subject to convective-tip boundary condition. The generalized results are presented and discussed in terms of dimensionless variables such as radial and axial Biot numbers (Bi r , Bi z ), Fin aspect ratio, L/R, and radial-to-axial conductivity ratio k * . Several special cases are derived from the general solution, which includes the insulated-tip boundary condition. It is also demonstrated that the classical temperature distribution and heat transfer rate from the two-dimensional isotropic pin Fin introduced earlier in literature can easily be recovered from the general solutions presented in this paper. Furthermore, dimensionless optimization results are presented for orthotropic pin Fins that can help to solve many natural and forced convection pin Fin problems.

  • Efficiency and Optimization of a Straight Rectangular Fin with Combined Heat and Mass Transfer
    Heat Transfer Engineering, 2008
    Co-Authors: Mostafa H. Sharqawy, Syed M. Zubair
    Abstract:

    An analysis was carried out to study the Efficiency of a straight rectangular Fin with a uniform cross-section area when subjected to simultaneous heat and mass transfer mechanisms. The temperature and humidity ratio differences are the driving forces for the heat and mass transfer, respectively. Numerical solutions are obtained for the temperature distribution over the Fin surface when the Fin surface is dry, fully wet, and partially wet. The psychrometric correlation of an air-water vapor mixture was used to simulate the relation between the temperature and humidity ratio instead of the linear approximate correlations used in the literature. The effect of atmospheric pressure on the Fin Efficiency was also studied, in addition to Fin optimum thickness for specific operating conditions. The numerical solution was compared with those of previous studies in order to Find if the linear model in the published analytical results are near to the real situation. It is found that the linear model for the relatio...

  • Efficiency and optimization of straight Fins with combined heat and mass transfer an analytical solution
    Applied Thermal Engineering, 2008
    Co-Authors: Mostafa H. Sharqawy, Syed M. Zubair
    Abstract:

    An analysis was carried out to study the Efficiency of straight Fins of different configurations when subjected to simultaneous heat and mass transfer mechanisms. The temperature and humidity ratio differences are the driving forces for heat and mass transfer, respectively. Analytical solutions are obtained for temperature distribution over the Fin surface when the Fin is fully wet. The effect of atmospheric pressure on the Fin Efficiency was also studied, in addition to Fin optimum dimensions. It is demonstrated that the closed-form solutions for a dry Fin case presented in many text books is a special case for the solutions presented in this paper.

  • Efficiency and optimization of an annular Fin with combined heat and mass transfer an analytical solution
    International Journal of Refrigeration-revue Internationale Du Froid, 2007
    Co-Authors: Mostafa H. Sharqawy, Syed M. Zubair
    Abstract:

    An analysis was carried out to study the Efficiency of annular Fin when subjected to simultaneous heat and mass transfer mechanisms. The temperature and humidity ratio differences are the driving forces for the heat and mass transfer, respectively. Analytical solutions are obtained for the temperature distribution over the Fin surface when the Fin is fully wet. The effect of the atmospheric pressure on the Fin Efficiency was also studied, in addition to Fin optimum dimensions. It is demonstrated that the closed-form solutions for a dry-Fin case presented in many text books are special cases for the solutions presented in this paper.