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:
- 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.
- 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:
Some of the important parameters are summarized below:
The various geometry and mesh are created from journal file, by varying the flocculation tank height. All the FLUENT settings including turbulence model, boundary conditions, solutions schemes etc. can be found in a sample of report summary for h/b=2 case.
Results and Discussion
Click here for the results of the series of simulation experiments and parameter analysis, completely summarized in an Excel workbook. Only parts of the results are given graphically below.
Take the values calculated from the 4th baffle, and plot each parameter as a function of h/b:
Pi_cell was shown to increase continually as h/b ratio increases in preliminary experiments, which was also reported in Fall 2008 research.