Mathematical modeling of the drying process in a fixed-bed dryer

The drying process in a fixed-bed dryer can be modeled in terms of balance equations of masses and energies that result in a hyperbolic system of conservation laws with a source term. This system is solved numerically by an operator-splitting technique based on Strang's algorithm. A similar approach has been used before in agricultural engineering research, but the system of equations was simplified to a set of ordinary differential equations by dropping certain terms. Comparison of numerical results indicates that this commonly employed simplification has not been fully justified and should be reexamined by further research work (e.g., carefully designed experiments accompanied by appropriate computation may be needed).