Defining Sources and Sinks for the Fracture Network

Each fracture set must have at least one source and at least one sink. Sources and sinks identify how incoming mass flux links and outgoing mass flux links are mapped to specific locations (pipes) in the Network pathway.

A source is a linked pathway (or boundary condition) which discharges mass to one or more pipes in the network. A sink is a linked pathway to which mass is discharged from one or more pipes in the network. As a result, any entry in the Source column of the Fracture Network editing dialog must be the name of an existing pathway with a mass flux link that discharges mass to the Network pathway (i.e., is an Outflow or Outflux pathway). Similarly, any entry in the Sink column of the Fracture Network editing dialog must be the name of an existing pathway with a mass flux link that receives mass from the Network pathway (i.e., is an Inflow pathway).

Note: There are two circumstances in which the entries in the Source column need not be existing pathway names: when combining flux inputs, and when defining initial and boundary conditions.

Note: There are two circumstances in which the entries in the Sink column need not be existing pathway names: when splitting flux outputs, and when using Watch Groups.

Multiple pipes can be associated with a particular source or sink. If the fracture network assigns multiple pipes to a source (i.e., if the same pathway is listed in the Source column for multiple pipes), GoldSim allocates the incoming flux from the source pathway to the pipes in proportion to their flow rates. If the fracture network assigns multiple pipes to a sink (i.e., if the same pathway is listed in the Sink column for multiple pipes), GoldSim collects the outgoing fluxes from these pipes and discharges them to the sink pathway.

Note that the fracture network does not have to terminate at the sources and sinks. A source or sink can be thought of as a "window" within the fracture network where species masses are injected or withdrawn.