Experimental and numerical research of heating process and the vapor transportation in a forced-convection oven

The vapour and temperature distributions in a multi-functional oven are of great importance to achieve desired food baking conditions. In order to analyze the characteristic distributions of the parameters and improve their uniformity, this study performed experimental and numerical tests for ovens with different structural optimizations. The temperature and vapor distributions were measured with thermocouple and vapour probes, and the characteristics of the parameters were evaluated and analyzed. A numerical model coupled with heat transfer, turbulent flow and species transportation was proposed and verified by the experimental measurements, and thus the flow field characteristics can be accurately described in the numerical simulations. The temperature and species distributions, which were affected by the heat conduction, convection and radiation were investigated to highlight the effects of different internal structures. Based on the results of the experimental and numerical, the factors contributing to the uneven distribution of the vapour specie and flow temperature were revealed and analyzed, and optimizations of the internal oven structures and auxiliary ventilation system were validated to improve the parameter distributions with the maximum temperature fluctuation decrease of 50.3 %, browning deviation decrease of 33.3 %, and average vapor fraction decrease of 31.9 % at the characteristic locations in the oven cavity. • A numerical model with heat transfer, turbulent flow and species transportation was proposed and verified to analyze the flow characteristics for a forced oven. • The effects of the oven structures on the distributions of the temperature and vapor concentration were systematically analyzed based on the experimental and numerical results. • The suction coefficient based on the mixture gas and supplied air was introduced to characterize the auxiliary ventilation system, and the structure of the auxiliary ventilation was also optimized.