Setting up Problem in FLUENT

With mesh created, we can now use FLUENT to set up the problem. Following steps illustrate what is needed to be done.

1. Import generated mesh file
2. Define turbulence model
   • Different turbulence model are appropriate for different flow properties
   • K-ε realizable model is chosen for the flow in flocculation tank (further discussed in later section)
3. Define materials (liquid water for our case)
4. Define operating conditions (use default operating pressure)
5. Define boundary conditions (Details below)
6. Set control solution
   • Select second order discretization method instead of first order method
7. Initialize the problem with the inlet properties
8. Set Residual to 1e-05
   • The residual is a measure of how well the current solution satisfies the discrete form of each governing equation
9. Solve the problem by iterating

 Defining Boundary Conditions

Figure 1.  Boundary conditions of flocculation tank

Figure 1 shows the boundary conditions of the flocculation tank. The top part of the flocculation is open, so a symmetry boundary conditions is employed. Set the inlet boundary condition to inlet velocity of 0.1 m/s. Outlet condition is set to pressure outlet. 

Table 1. Boundary conditions