Simulation of food drying processes by Computational Fluid Dynamics (CFD); recent advances and approaches

Background: Understanding the mechanisms underlying the drying processes has a critical role in dehydration of food and agricultural products. Advanced computer modeling and simulation techniques can help in developing new dryers, modification of current systems, energy saving and process optimization. Also the most important parameter during the drying food products is food quality (moisture content, crack formation, case hardening, etc.) which can be enhanced through using appropriate modeling. Computational Fluid Dynamics (CFD) is a well-known modeling technique which has received more attention in the food industry in the recent years. Hydrodynamics of fluid flow, heat and mass transfer during drying can be predicted using CFD. Scope and Approach: This article reviews fundamentals, merits and shortcomings of CFD in the drying process modeling with a special focus on dehydration of food products. Since the drying is a growing unit operation, there is an emphasis on investigation of CFD utilization in modeling emerging drying processes of food products such as microwave assisted drying, infrared and superheated steam drying besides conventional convective drying systems notably in recent 5 years. Key Findings and Conclusions: CFD has been considered as a promising method which could help developing the design of new dryers, enhancing current dryers and the most important aspect of utilization of this method in the food industry research and development is "food quality" improvement.