Heat conduction in multilayer spherical products by transfer functions

The development of a computer program is presented in order to determine the heat conduction transfer in multilayer spherical products, hollow or solid, by means of the transfer function method. We can establish a methodology in order to determine heat flux and inner and/or outer temperatures for spherical solid multilayer products, and heat flux and temperatures in any intermediate point of the spherical multilayer products both hollow and solid. The program developed is designed for variable intervals and it allows for the inclusion of the superficial convection coefficient in the cases where it remains constant, or its exclusion from the mathematical model in the cases where it does not remain constant, as well as in the cases in which it does not exist (heating or cooling by superficial contact). The method was validated with oranges of average diameters between 7.73 and 7.89 cm and thickness of rind between 4.7 and 6.8 mm, and these showed good results. (C) 1998 Elsevier Science Ltd and IIR. All rights reserved.