Determination of the effective thermal diffusivity in a porous bed containing rice grains: effects of moisture content and temperature

Autor: Marcos Flávio Pinto Moreira, Guilherme Luiz Dotto, Luiz Antonio de Almeida Pinto
Rok vydání: 2015
Předmět:
Zdroj: Heat and Mass Transfer. 52:887-896
ISSN: 1432-1181
0947-7411
DOI: 10.1007/s00231-015-1604-5
Popis: The effective thermal diffusivity (α ef ) of a porous bed containing rice grains was determined under different experimental conditions. The α ef values were estimated by the Log method. The effects of rice moisture content (2, 12 and 22 % w.b.) and temperature (15, 35, 55 and 75 °C) on the α ef values were investigated. Finally, an empirical model was proposed to represent the effective thermal diffusivity as a function of the moisture content (X) and temperature (T). The results revealed that the increase in the rice moisture content and temperature caused an increase in α ef values, which ranged from 0.91 × 10−7 to 3.23 × 10−7 m2 s−1. In the studied range, the dependence of α ef with the rice moisture content and temperature can be represented as: α ef (m2s−1) = (0.63 + 5.63 × 10−2 X + 1.51 × 10−2 T + 1.17 × 10−4 XT) × 10−7. The proposed empirical model was suitable to predict the α ef values with mean absolute percentage deviation of 3.8 % and is a tool for future modeling purposes.
Databáze: OpenAIRE
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