To even out drying conditions and thereby improve meat product processing, modern dryers run with a ventilation cycle, during which, while the total airflow rate remains steady, the airflow rate ranges reciprocally from a low to a high level in each of two blower ducts located on either side of the plant. In this work, using a two-dimensional computational fluid dynamics model with time-dependent boundary conditions (i.e. an unsteady model), the homogeneity of the distribution of the air velocity in an industrial meat dryer is discussed for several low and high levels of the ventilation cycle, and two forms of this cycle (linear and sinusoidal). The changes in the airflow structure due to dissymmetry occurring in the ventilation cycle are also evaluated. All airflow simulations are consistent with the heterogeneity of drying usually observed in practice. This work can provide professionals with a rational approach to help them in the operation and design of modern dryers. (C) 2003 Elsevier Science Ltd. All rights reserved.