Modification and further development of a simulation package for in-store drying and aeration of grains

Drying Simulation was originally developed and compiled in Microsoft BASIC 7.0 to provide a PC-based user-interactive environment for computer simulation of forced-convection in store drying and aeration of rough rice (JINDAL and MARTINEZ, 1992). This package relies on the modified Thompson et al. (1968) and the Thompson (1992) near-equilibrium models to simulate grain drying and rewetting in deep beds. Drying simulation was further development and modified for use with soybeans and corn. More than sixteen new features were added for making the simulation program more user-friendly and easily accessible. Some important new features are the flexibility of program to select grain types as well as the equations used in the models for a simulation run. Equations that users can select correspond to thin-layer drying, thin-layer rewetting, equilibrium moisture content (EMC), latent heat of vaporization and specific heat. The data files for grains and air in non-uniform conditions can be created or edited directly in the simulation program. The HELP feature provides help on-line to users. The simulation results can now be saved to files, viewed on the screen or printed out with a better format. The energy requirements were also displayed on screen during a simulation run. The package was also modified to run on a monochrome monitor. The sensitivity of the simulated moisture contents was analyzed with regard to the equations used in the simulation models. Results showed that the selection of thin-layer drying and rewetting equations greatly influenced simulated results. Latent heat of vaporization and specific heat equations had minimal effects on the simulated moisture contents. A comparison of reported experimental and simulated moisture contents was also made. Result showed that, generally, a good agreement between the simulated results and reported data for rough rice. However, it was not possible to make such comparisons extensively for soybeans and corn in absence of the availability of experimental data in the published literature.