ON ONE VARIATIONAL PRINCIPLE FOR HEAT-CONDUCTION PROCESSES.

The fundamental postulates of nonequilibrium thermodynamics and generalization of the experience of classical thermodynamics are used as a basis for formulating a variational principle of heat-conduction theory that makes it possible to employ direct methods of variational calculus both for space variables and for time. A solution of the one-dimensional problem of nonstationary heat conduction with a nonlinear boundary condition, obtained on the basis of the proposed principle with the aid of the Ritz method, has been compared with a numerical solution. Satisfactory accuracy of the results is indicated even when simple functions are employed to approximate the temperature field.