Particle Tracking Simulation Period


Particle Tracking Simulation Period
Conditions:	if the Include Advection Dispersion (AD) Water Quality option selected in the Simulation Specification dialogue and the Random Walk particle tracking option is selected

PT Simulation Period

The particle tracking simulation does not have to be the same length as the water movement simulation. The only restriction is that the start date for the particle tracking simulation must be within the water movement simulation.

Flow Results for Particle Tracking Simulation

A particle tracking simulation requires the cell-by-cell water fluxes calculated by the water movement simulation. However, the particle tracking simulation does not have to be the same period as the water movement simulation. Therefore, the user interface is flexible in how it will use water movement cell-by-cell flow data.

No recycling on results - In this case, the water quality simulation end date must also be within the water movement simulation period, which means that the water quality simulation cannot extend beyond the water movement simulation.

Recycling on flow results - In this case, the water quality simulation can be much longer than the water movement simulation, based on a repeated set of water movement results. The water quality simulation starts on the Start Date with the flow results from the Cycle Restart Date. When the water quality simulation period reaches the Cycle End Date, the WQ simulation will continue but the flow results will be restarted at the Cycle Restart Date.

If the recycle dates do not match one of the saved time steps, then the nearest saved time step is used.

For example, you may have a two-year water movement simulation but you may want to simulate water quality for 10 years. To do this, you would specify the start and stop dates of the part of the water movement simulation that you want repeated. If you want to repeat the whole water movement simulation, then you would specify the beginning and end of the water movement simulation.

Constant water movement flow field - In this case, the nearest saved time step to this date will be used as a steady-state flow field for the transient water quality simulation.