Gtheta Computations using UDF
A User Defined FLUENT script (UDF) was created to extract the G_theta value from the flocculator. The UDF loops through all of the individual cells of the converged solution, and extracts the energy dissipation^1/2 times the cell area. The sum of this quantity for all cells divided by flow and square of viscoisty results in the G_theta value of the entire flocculator as shown in equation 1.
Gθ_baffle=1/Q*vis^(-1/2)*∑(ε^(1/2)*cell_area) Eq. 1
The above formulation has been determined (with Monroe's help) by weighting the value of Gθ by volume.
The Gθ_baffle values weighted by the area or number of cells were also examined, but these formulations do not produce sensible results.
Below is the G_theta value presented for flocculation tanks of different geometries:
Case Geometry (h-height,b-width,N-baffles) |
Gθ_Flocculator |
|---|---|
b=.1, h=1, N=1, Clearance height=.15 |
430 |
b=.1, h=.3, N=5, sym bc |
1330 |
b=.1, h=.2, N=5 |
1060 |