Simulate oven-baking using computational fluid dynamics.

Computational fluid dynamics (CFD) is a powerful simulation tool that uses finite element methodologies to model fluid and heat transfer processes. Using CFD simulation techniques can help us understand the phenomena that occur simultaneously in the oven baking process--heating, vaporization and volume expansion.

You can use CFD to predict what will happen, quantitatively, when fluids flow. This often involves the simultaneous flow of heat, mass transfer, phase changes, chemical and mechanical reactions and stresses. The goal of Canadian researchers was to develop three dimensional (3-D) computer simulations of small baking ovens. These models would be used to predict dynamic and spatial temperature, and velocity distribution inside such ovens.

CFD software was used to develop a 3-D model of a small baking oven whose inside dimensions were: 0.7 m X 0.48 m X 0.56 m. The processes of conduction, wall-to-wall radiation and convection were used in the simulation program. Air thermal volume expansion was considered as the source of air movement. Investigators installed 15 thermal couples at different locations inside the oven to record the temperature histories that were then used to validate the model.

Simulation results indicated that inside the oven there were three temperature zones: a high zone (HZ), a middle zone (MZ) and a low zone (LZ). The high-temperature zone was located around the electrical resistance. The middle zone included the areas that were used to keep products from direct heating at the top of the oven. The low-temperature zone was in the middle of oven, which is normally where products are placed.

The temperature changed significantly in the HZ, while it was stable in the LZ. The air velocity was dependent on the location and heating time. Maximum velocity was about 0.01m per sec. The results show that 3-D computer simulation of baking ovens is able to provide data on temperature and velocity distribution. This information can be useful when designing ovens and optimizing the heating process.

Further information. Michelle Marcotte, Food Research and Development Center, Agriculture and Agri-Food Canada, 3600 Cassavant Blvd W., St., Hyacinthe, QC J2S 8E3, Canada; phone: [phone]; fax: [phone]; email: [e-mail].