Sensitivity Analysis for Hygrostress Crack Formation in Cylindrical Food During Drying

摘要

A parametric analysis was performed to examine the influence of several factors on stress crack formation in cylindrical food during drying using a previously developed, validated simulation method. They included ini- tial food moisture (W_o), air humidity (R_h) and temperature (T_a), convec- tive surface mass transfer coefficient (h_m), convective surface heat transfer coefficient (h_t), moisture diffusivity (D_w), and initial food di- ameter (d_o). R_h influenced most strongly drying time for crack formation (t_cf), followed by T_a and W_o. The other 4 parameters in descending order of influence were h_m, h_t, d_o and D_w. The influence of all parameters, except W_o, was due to their influence on mass transfer Biot number, Bi_m, that was closely related to moisture concentration gradient in food. The influence of W_o was due to increased critical stress for crack formation with a reduced moisture level.