Revolving Rice Dryer Using DPM CFD Simulation

Rice Dryer Using DPM (Revolving ), CFD Simulation Ansys Fluent Training

In this project, a revolving rice dryer device was simulated using Evaporating droplets with a one-way DPM model in Ansys Fluent software, and then the results were investigated. Hot air enters the rice dryer through the holes in a porous tube located at the center of the enormous chamber. About three million rice particles are injected with 15% moisture droplets into a chamber revolving with 100rpm angular speed.

Geometry & Mesh

The 3D geometry was generated in Design Modeler software. A cylinder with a 4.5m diameter and 1.68m  height.

In addition, an unstructured mesh grid was carried out using Ansys meshing software, and overall, 2703907 elements were generated.

CFD Simulation

Several assumptions have been considered to simulate Revolving rice dryer, including:

• The simulation is Transient(unsteady) in order to capture the behavior of fluid and particles over time.
• The pressure-based solver type was used due to the incompressibility of the working fluid(air).
• The One-way Discrete Phase Model(DPM) was utilized, so the grains of rice particles were injected with our desired condition into the fluid domain.
• Gravitational acceleration effects were considered 9.81m/s^{^2} in z-direction.

The following table represents a summary of the solution:

Results

After injecting about three million rice particles through the inlet, they gather around the porous tube in the middle of the chamber. As shown in figure 1, H2o mass fraction concentrated around the tube at first, but after a while, due to the release of hot air from tube holes to the chamber, the evaporating process begins and causes vaporizing material(H2o) to disperse; This may reduce the moisture of rice particles which was 15% at the beginning and as a result, the diameter decrease that depicted in figure 2. In addition, the Rotational speed of the chamber accelerates the circulation of hot air.