This set of simulations were done at a constant flow rate (18,000 gpm). This work is done before field studies to get initial impressions of the flow in this tank. It also provide guidence for planning the field study.

Comparison of these results with simulations of different boundary conditions (e.g. July 21 to 23, 1997 Field Study and Simulation) provides useful insight such as sensitivity of tracer mixing.

Below the Baseline case with constant fill and draw rates is shown.

Geometry and Mesh for Tank (1100x850 GIF 40K).

This image shows the tank geometry and mesh. Inlet and outlet area are shown with additional detail. This mesh has ~64,000 cells.

Tank Geometry near Inlet and Outlet pipe (1100x850 GIF 18K).

This image shows the details of the tank geometry near the inlet and outlet pipe. Both inlet and outlet pipes are below the elevation of the floor of the tank.

Distribution of Influent after 36 minutes (1100x850 GIF 31K).

This image shows the distribution of a tracer fed to the tank during the filling cycle. This is the distibution after 36 minutes at a depth of 6 feet. The interaction of the inlet jet with the nearest pillar creates a pair of jets. More distant pillars appear to have little additional effect.

Velocity Magnitude (1100x850 GIF 30K).

This image shows the distribution of velocity magnitude in the tank after 36 minutes. This flow field is still developing.

Velocity Field (1100x850 GIF 52K).

This image shows the velocity field in the tank. This is not a converged steady flow field. It looks as though the flow field is settling down though. It is interesting to note that the flow field is very nearly 2D. There is little difference in the field at any height with the exception of near the inlet.

Velocity Magnitude (1100x850 GIF 30K).

This image shows the distribution of velocity magnitude in the tank after the flow field is in steady state. Velocities in tank range from 1mm/sec to 2 cm/sec (except near the inlet). Flow in the "Quadrant #3" Corner is stagnant, and mixes by diffusion only.

Velocity Field (1100x850 GIF 52K).

This image shows the velocity field in the tank after 4 hr, 40 minutes. This is a converged, steady flow field for the inlet flow condition of 18,000 gpm. Note the relatively strong circulation pattern on the right side of the tank. Most of the flow on the left side of the tank is near the barrier. The flow field remains very nearly 2D. There is little difference in the field at any height with the exception of near the inlet.

Distribution of Influent after ~2.5 hours. (1100x850 GIF 31K).

This is the influent tracer distibution after ~2.5 hours at a depth of 6 feet. The impact of the two jets are not as pronounced on the flow within the left portion of the tank as during earlier times. This trend continues with time.

Distribution of Influent after ~4 Hours, 40 minutes. (1100x850 GIF 31K).

This is the influent tracer distibution after ~4 hours, 40 minutes at a depth of 6 feet. Tracer has arrived at the right side of the tanker sooner that perfect plug flow would predict.

Distribution of Tracer after ~19 Hours, 43 minutes. (1100x850 GIF 31K).

This is the tracer distibution after ~19 hours, 43 minutes at a depth of 6 feet. The tank was filled for ~5 hours, then drawn for ~5 hours, then filled for 10 hours. The region of the tank near the baffle on the outlet side of the tank and near the gap, mixes poorest with the tracer. This is due to the velocity field in the tank during both fill and draw cycles.

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