Solution Of Heat Flow Problems Research Articles

Thermal Modelling of Induction Motors Based on Accurate Loss Density Distribution

The ability to predict the temperature rise of a machine prior to its construction is as important as the ability to predict its performance. For a complex heat flow systems, such as electrical machines, the lumped parameter network technique still plays a very important role for the solution of heat flow problems. This paper discusses the development of the thermal model, taking into account the different material types and complicated geometries within the machine, as well as the different modes of heat transfer. However, to predict an accurate temperature distribution requires the knowledge of loss distribution in the machine. Using the temperature-time method a more accurate loss distribution is obtained. The model performance is validated against measured results obtained for a 4 kW, 3-phase, 4-pole, 415 V totally enclosed fan cooled induction motor.

A Note on the Alternating Direction Implicit Method for the Numerical Solution of Heat Flow Problems

A Note on the Alternating Direction Implicit Method for the Numerical Solution of Heat Flow Problems

A note on the alternating direction implicit method for the numerical solution of heat flow problems

1. Introduction. In companion papers [1; 6] recently Peaceman, Rachford, and the author introduced a finite difference technique called therein the alternating direction implicit method for approximating the solution of transient and permanent heat flow problems in two space variables. The validity of the method was established only in the case of a rectangular domain. Since then the procedure has been tested successfully on several more complex examples [4] without proof. The purpose of this short note is to prove in the case of non rectangular domains that the solution of the alternating direction method for the parabolic problem converges to the solution of the differential equation as the increments of the independent variables diminish in a proper manner, that the iterative adaptation for the elliptic problem converges to the solution of the Laplace difference equation, and to give an efficient choice of the parameter sequence involved in this iteration. 2. Parabolic problem. Let D be an open, connected set in the plane bounded by a curve C made up of closed polygons with sides parallel to the coordinate axes. Assume, moreover, that there exists a sequence

Heat-Conduction Problems in Presses Used for Gluing of Wood

The application of heat-flow equations to the heat-flow problems in wood-gluing presses is considered. By means of a transmission-line analogy, the solution of heat-flow problems with internally generated heat is greatly simplified. The general equation is set up and applied specifically to the problem of radio-frequency heating of wood, while the wood is contained between two cool plates. Comparison of this type of heating with the usual hot-plate-press method reveals important advantages for the radio-frequency method. The formulas developed have been illustrated by means of curves based upon the constants of wood. However, the general equations apply as well to the heating of any other insulating material, where the heating by radio frequency is done by essentially a dielectric-loss phenomena.