A simple turbulence model for non-Newtonian fluids, as an analogy to eddy viscosity of Newtonian fluids, was developed. With this model, velocity and temperature distributions in a tubular heat exchanger were simulated with the temperature-dependent physical and rheological properties of soybean milk. The numerical program developed was verified with analytical solutions of non-Newtonian laminar flow. In order to verify the suggested turbulence mode, the bulk temperatures of 9% soybean milk were obtained from the analytical calculation at various axial locations in a tubular heat exchanger under turbulent flow conditions. The bulk temperatures showed only 4.8% deviation from the cross-sectional average temperatures obtained from numerical simulation. The simulated velocity and temperature distributions in a heating tube were verified by measuring the residence times and temperatures at the end of the heat exchanger. (C) 2002 Elsevier Science Ltd. All rights reserved.