A detailed calculation of the flow pattern of milk between two corrugated plates was carried out using 2D and 3D computational fluid dynamics (CFD). The 2D calculation shows the influence of the corrugations shape, but the 3D calculations are necessary to assess the importance of the corrugation orientation. The influence of the inlet flow extends only up to three corrugations. A model was constructed that allowed for a positive qualitative validation of the simulation results. The calculations can help identifying those regions where turbulent backflows and thus higher temperature regions near the wall can occur. These regions are the most sensitive to fouling and should be avoided as much as possible through better design. In this respect, CFD can be regarded as a valuable assistant for optimal designing of plate heat exchangers. (C) 2002 Elsevier Science Ltd. All rights reserved.