resistance to air flow across a thin green fig bed

green fig, which is usually consumed as dry fruit, is one of the important non-oil export agricultural commodities of iran. in this study, some important physical properties of green figs including geometric mean diamter, sphericity, porosity, particle and bulk density and pressure drop across a thin bed were measured at constant moisture content of 6% (dry basis). air flow ranges used in this study were 0.4-1.0 m3 s-1 m-2 at three temperatures. the fig kernels were put together in thin layers in four different arrangements. the effect of filling methods and air flow rates on pressure drop were highly significant, while the air temperature did not show any appreciable effect on air flow resistance. three applicable and most versatile models (shedd, hukill and ives, and ergun) were used to evaluate the pressure drop data. the ergun model, with higher values of coefficient of determination (r2= 0.989) and lower value of root mean square error (rmse= 21.84) and mean relative deviation modulus (p%= 6.69), was selected to be the best model for predicting pressure drop across green figs thin layer bed for the conditions studied.