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Current work is devoted to the modeling calculation aimed on answering the question of how the heating sector will look like after transformation from current fossil fuel generation to potential RES-based generation till 2050: what equipment, fuel types will be used, how energy consumption will change, what are the limitations in the sectors, drivers of development of RES in heating sector, needed investments, CO2 reductions and jobs created according to the installations implemented. The results of such modeling could demonstrate principal possibility of achieving of determined RES-based heat generation targets drawing up the heating sector architecture till 2050. [ABSTRACT FROM AUTHOR]

Unsteady MHD free convection flow past a vertical porous plate in porous medium with radiation, diffusion thermo, thermal diffusion and heat source are analyzed. The governing non-linear, partial differential equations are transformed into dimensionless by using non-dimensional quantities. Then the resultant dimensionless equations are solved numerically by applying an efficient, accurate and conditionally stable finite difference scheme of explicit type with the help of a computer programming language Compaq Visual Fortran. The stability and convergence analysis has been carried out to establish the effect of velocity, temperature, concentration, skin friction, Nusselt number, Sherwood number, stream lines and isotherms line. Finally, the effects of various parameters are presented graphically and discussed qualitatively. [ABSTRACT FROM AUTHOR]

Time independent mixed convective boundary layer flow of a viscous fluid over a porous stretching wedge is investigated analytically. The porous wedge is subjected to Newtonian heating in the existence of heat generation/absorption. Employing non-dimensional transformations the governing PDE's converted to nonlinear ODE's which are further solved by using homotopy analysis method. The convergence of the solution is properly checked and the effects of various involved parameters on velocity and temperature distributions are illustrated through graphs. The reliability and effectiveness of HAM have been verified by comparing the present analytical results with existing numerical results for skin-friction coefficient. The results are found to be in good agreement. [ABSTRACT FROM AUTHOR]

The mixed convection flow within a vertical channel having internal heat generation at a rate proportional to a power of the temperature difference is considered. The analysis is concerning the studies of occurrence of flow reversal and the effects of three dimensionless parameters, identified as the internal heat parameter (G), a mixed convection parameter and the exponent (p) in the local heating term on the fully developed double diffusive mixed convection flow in a vertical channel. The governing equations are solved numerically via MAPLE. It was found that flow reversal occurs with larger values of internal heat parameter and mixed convection parameter, but smaller values of local-heating exponent. They also show that, unlike the internal heat parameter and the local-heating exponent, the mixed convection parameter do not give any significant effect on the temperature. [ABSTRACT FROM AUTHOR]

This study investigates free convection about a heated infinite horizontal circular cylinder in a Newtonian fluid in the presence of heat generation. The cylinder is fixed and immersed in a stationary fluid, in which the temperature is uniformly heated about the temperature of the surrounding fluid. The governing equation is non-dimensionlized and solved numerically by employing a finite difference method. The effects of heat generation parameter,ã and the Prandtl number, Pr, of the temperature and velocity profile are shown graphically. It is found that the presence of heat generation significantly increases the temperature and velocity distribution thus as Pr increases, the temperature and velocity distribution decrease too. [ABSTRACT FROM AUTHOR]

The optimization of grinding parameters for silicon wafers is necessary in order to increase the reliability of electronic packages. Grinding is a mechanical process performed on silicon wafers during which heat is generated. The amount of heat generated affects the reliability of the wafer, and implicitly that of the final product. This paper describes the work performed to simulate the heat generated during a back grinding process for silicon wafers using the commercial finite element code ABAQUS. The grinding of a silicon wafer with a thickness of 60 μm mounted on a carrier wafer using bond adhesive material was simulated. The heat generated is caused by the friction between the grinding wheel and the backside of the silicon wafer. The computed temperature change due to friction in the wafer was compared with experimental and numerical values, and showed a good correlation. The numerical model developed can be used to better understand the local grinding temperature in the wafers and to estimate the effect of the grinding parameters on the temperature rise. [ABSTRACT FROM PUBLISHER]

The article discusses a study which proposed several direct electrical heating (DEH) designs for flow assurance. Particular focus is given to the advantages of the proposed DEH designs including reduced power cable dimensions, simplified electrical connections to pipelines and reduced number of anodes. It describes the process of using DEH in subsea oil production. It also outlines improved subsea configurations with pipelines for reducing the heat loss in feeder cables.

This paper is focused on the study of the problem of MHD heat and mass transfer by mixed convection flow in the forward stagnation region of a rotating sphere in the presence of heat generation and chemical reaction effects. The surface of the sphere is maintained at constant fluid temperature and species concentration. The governing equations of the problem are converted into ordinary differential equations by using suitable similarity transformations. The self-similar equations are solved numerically using an efficient iterative implicit finite-difference method. The numerical results are compared with previously published results on special cases of the problem and found to be in excellent agreement. The obtained results are displayed graphically to illustrate the influence of the different physical parameters on the velocity components in x- and y-directions, temperature and concentration profiles as well as the local surface shear stresses and local heat and mass transfer coefficients. [ABSTRACT FROM AUTHOR]

Synthetic defects are an important tool used for characterizing the performance of nondestructive evaluation techniques. Viscous material-filled synthetic defects were developed for use in vibrothermography (also known as sonic IR) as a tool to improve inspection accuracy and reliability. This paper describes how the heat-generation response of these VMF synthetic defects is similar to the response of real defects. It also shows how VMF defects can be applied to improve inspection accuracy for complex industrial parts and presents a study of their application in an aircraft engine stator vane. [ABSTRACT FROM AUTHOR]

Vibrothermography is a nondestructive evaluation (NDE) technique that has shown great promise in detecting tight cracks that can often be missed using other NDE methods. Vibration applied to a structure containing cracks forces crack faces to rub together and generates frictional heat imaged with an infrared camera. The closure state of a crack controls the locations and magnitude of heat generation in a vibrated crack. Noncontacting regions of cracks and regions under large closure stresses generally do not rub together to generate heat. Heat is generated at contacting regions of crack faces under low closure stresses. Regions along a crack that generate heat can be modulated based on externally applied stresses. The closure state of a crack, the level of applied vibration, and externally applied stresses influence the regions of a crack that will generate heat and those that will not. Due to the nature of the heat generation process, some cracks that are not detectable using other NDE methods are readily detectable using Vibrothermography. [ABSTRACT FROM AUTHOR]

In this paper we investigate the heat generation mechanisms that occurs during excitation of a specimen with high-power ultrasound (20 kHz and above). In order to obtain stable and easy to interpret results we use a set-up with a tunable piezo instead of an ultrasound welding system commonly used and excite the specimens at their resonance frequencies. We will report the results of recent investigations which reveal several different mechanisms contributing to the overall thermal signal. Besides frictional effects at crack faces also thermoplastic heating may occur at crack tips. In materials with high sound attenuation the heating of the bulk material itself can be measured. In this case the detected infrared signal corresponds to local stress fields of the induced vibration. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]