An analog method for the solution of unsteady radiant heat-transfer problems with combined conduction and convection.

An extension of Oppenheim's network method has been developed for the solution of unsteady heat-transfer problems with combined radiation, conduction, and convection. It is shown that, in the general case, the derivation of the temperature or heat-flux distribution reduces to the solution of a coupled set of nonlinear, first-order, difference equations. The result for steady-state problems with combined modes of heat transfer is a coupled set of nonlinear algebraic equations. In either case, solution on a digital computer is readily accomplished. An application of the method to the calculation of the temperature distribution on the radiative nozzle extension of a rocket nozzle is presented, and the resulting temperature profile is compared with experiment. Agreement to within approximately 2% of the equilibrium solution is demonstrated.