Parameters analysis in 2D - simulation experiments

Objectives and Hypothesis

The preliminary simulations had encouraging outcomes about the dependence of performance parameters on h/b ratio. In further experiments described below, we simulated a series of cases with h/b ratio of 2, 3, 4, 5, 8, 10, 15, 20 and 40 and plotted each performance parameters as a function of h/b ratio. We would expect:

1. K_baffle is a measure of energy loss within each baffle spacing. It will converge as h/b ratio increases, and will also converge in a single baffle for successive turnings. Shultz and Okun has suggested its value is between 3 and 4.
2. Pi_cell will increase as h/b ratio increase, which measure the active volume of flocculation tank. Pi_cell/(h/b) can be a measure of the active fraction of flocculation tank, which is expected to decrease as h/b ratio increases.

Methods and Procedures

h/b ratios of 2, 3, 4, 5, 8, 10, 15, 20 and 40 were tested with 5 baffles. The completed test are summarized in the following table:

preliminary simulation experiments

• To investigate the appropriate boundary condition settings and the convergence level

Simulations with various h over b ratios
According to the results of the preliminary simulation experiments, the simulation are design in following ways:

• Mesh generation
  • The mesh files for various h over b ratios are generated using the journal file
• Define the problem in FLUENT
  • Click here for a report summary of all parameters of FLUENT model
• Formulations of the performance parameters

  • Click !here^CFD tasks.ppt|width=32,height=32! for a summary of the derivation and formulation of the performance parameters

Results and Discussion

Click here for a summary of the calculated
parameters

Pi_cell was shown to increase continually as h/b ratio increases in preliminary experiments, which was also reported in Fall 2008 research.