  A numerical investigation of a solar greenhouse tunnel drier (SGTD) has been
performed. In the present study, the geometry of the tunnel roof is assumed
semi-circular which is covered with a UV (200\mu) stabilized polyethylene film.
The simulated SGTD reduces moisture of copra from 52.2% to 8% in 55 h under
full load conditions. A system of partial differential equations describing
heat and moisture transfer during drying copra in the solar greenhouse dryer
was developed and this system of non-linear partial differential equations was
solved numerically using the finite difference method (FDM). The numerical
solution was programmed in Compaq Visual FORTRAN version 6.5. The simulated
results reasonably agreed with the experimental data for solar drying copra.
This model can be used to provide the design data and is also essential for
optimal design of the dryer. For instance the user is able to change the
radiation properties of the roof cover for different materials of roof cover.
