Specifying the Outflow Requests for a Pool

By default, a Pool element initially has one Outflow Request (named Outflow1). You can add additional Outflow Requests by pressing the Add button. Outflows can be deleted using the Remove button, and moved up and down in the list using the two buttons to the right of the Remove button.

Note: You cannot delete an Outflow Request if it is the only one (there must always be one). Of course, it can be set to zero (which is the default).

The names of the Outflows can be changed by editing the items in the Name column.

For each Outflow Request in the list, you specify the actual Request. The Request has the same dimensions as the Flow Units.

Requests can be specified as constants or expressions and/or links, and may change with time.

Note: The specified Requests represent constant rates over the next timestep. Hence, if a Request was defined as “if(time > 10 day, 2 m³/day, 1 m³/day)”, and you were using a 1 day timestep, the Request would not actually change to 2 m³/day until time = 11 days. That is, since at time = 10 days, the if statement indicates that the Request is equal to 1 m³/day, GoldSim would assume that the Request was equal to 1 m³/day between 10 days and 11 days. If you wanted the Request to change at 10 days, you would write the if statement as “if(time >= 10 day, 2 m³/day, 1 m³/day)”.

GoldSim sums the Outflow Requests to compute the Total_Request output. If the Pool stays above the Lower Bound (or there is no specified Lower Bound), then the Total_Outflow output is equal to the Total_Request. If the Pool reaches the Lower Bound, however, GoldSim compares the Total_Request to the amount of material available, and the Total_Outflow is computed such that it represents what can actually be withdrawn from the Pool at that time (which, depending on the Inflows, may be less than the Total_Request).

Note that if the Total_Outflow is limited (such that it is less than the Total_Request), and there are multiple Outflow Requests, it becomes necessary to allocate the Total_Outflow among the requests. This is done based on the specified Priority for each Outflow Request.