Flows

Flows fill and drain accumulations. The unfilled arrow head on the flow pipe indicates the direction of positive flow.

The default flow type is the uniflow, which flows in one direction only. You can also use a biflow (bi-directional flow).

To place a flow on the diagram

1. In the Build toolbar, choose a flow type from the Flow dropdown menu.
2. Click the flow tool. The cursor will change to a flow icon.
3. Click and drag to add the flow, and define its start and end. Click a stock or other variable to connect to it as you add the flow. You can connect both the start and end points of the flow by clicking a variable, then dragging to another variable.
4. In the Properties panel, enter an equation and other properties.

   For more information about placing, naming, and editing flows, see Working with Building Blocks.

Working with Flows

To bend a flow pipe

• Bend a Flow pipe - When you click and drag to place the flow, press the SHIFT key as you drag. Each time you press the SHIFT key while dragging, a 90-degree bend is inserted in the flow pipe.

  Tip: If the flow is connected on both ends, disconnect one end, add bends, then reconnect it. Once the bends are added, you can drag them by their handles.

• Draw an outflow from a stock - With the Flow tool selected, click a stock, then drag to place the flow. The flow is connected to the stock and flows from it.
• Draw an inflow to a stock - With the Flow tool selected, click to place the flow, then drag to a stock. The flow is connected to the stock and flows to it.
• Draw outflow and inflow at the same time - When adding the flow, click one stock and drag to another stock. The flow connects the two stocks and flows between them.
• Connect a flow - Click the flow to select it, then drag a cloud to a stock to connect it.
• Disconnect a flow - Click the flow to select it, then drag a handle away from a stock. A cloud will appear at the disconnected end of the flow.
• Change the direction of a flow - Ctrl-click (Windows) or ⌘-click (Mac) the flow arrowhead. The arrowhead will move to the opposite end of the flow. For biflows, the positive and negative arrows will switch to opposite ends.

For more information about polarity, see Assigning Polarity to Connectors.

To create leakage flows for conveyors

Second and subsequent outlfows for conveyors are automatically defined as leakage flows. Use the following procedure to add and define a leakage flow for a conveyor.

1. Add a second (or subsequent) outflow to the conveyor.
2. Select the second (or subsequent) flow.
3. Click the Equation panel.
4. In the "Options" section, use the Leakage, Leak integers, and Leak zone options to define the leakage represented by the flow. For information about each of these options, see Flow options.
5. In the "Parameters" section, specify the leakage fraction. For more information, see Flow parameters.

To define queue outflows

• A queue can have multiple uniflow outflows.
• A queue's outflows are constrained only when they're in an oven or an inflow-limited and/or capacity-constrained conveyor immediately downstream of the queue.
• Unit conversion is possible in flows that connect queues to other stocks. For more information, see the discussion of the Unit conversion check box in Equation Tab.
• When a queue has multiple outflows, you can designate one or more of the outflows as an "overflow". When a higher priority flow is blocked because of capacity constraints, the flow will be routed through the overflow. For more information, see the discussion of the Overflow check box in Equation Tab.

To define oven outflows

• An oven can have a single uniflow outflow.
• An oven's cook time is specified in the oven's parameters. When the oven's cook time has expired, the oven will spit out its entire contents in an instant. At all other times, the oven's outflow will be zero.
• Unit conversion is possible for oven outflows. For more information, see the discussion of the Unit conversion check box in Equation Tab

See Also