Direction Documentation

The data format allows the user to specify the design criteria associated with direction of flow through an edge. For example, a pipe can be designed to allow bi directional flow, in which case the flow may travel in either direction through the pipe. Or, a pipe may be designed for uni directional flow. In which case, the flow may only travel from the from junction to the to junction. In certain cases, it may be desirable to specify a direction flow that goes beyond the physical characteristics of an edge. For example, while a pipe may be designed for bi directional flow, a user may find it useful to specify in case that the flow should be in "reverse" direction. For such situations, the key word flow_direction has been reserved to allow the user to specify a direction of flow, where flow_direction=-1 denotes reversal of flow, flow_direction=0 denotes unspecified direction, and flow_direction=1 denotes forward flow. The next few tables describes the behavior of flow_direction when combined with design criteria for flow.

Pipe

is_bidirectionalflow_directiondescription
1-1reverse flow only
10flow in both directions
11forward flow only
0-1no flow
00forward flow only
01forward flow only

Compressor

directionalityflow_directiondescription
0-1reverse flow with compression
00flow and compression in either directions
01forward flow with compression
1-1no flow
10forward flow with compression
11forward flow with compression
2-1reverse flow without compression
20forward flow with compression or reverse flow without compression
21forward flow with compression

Regulator

is_bidirectionalflow_directiondescription
1-1reverse flow with no pressure reduction
10reverse flow with no pressure reduction or forward flow with pressure reduction
11forward flow with pressure reduction
0-1no flow
00forward flow with pressure reduction
01forward flow with pressure reduction

Valve

is_bidirectionalflow_directiondescription
1-1reverse flow only
10flow in both directions
11forward flow only
0-1no flow
00forward flow only
01forward flow only

Resistor

is_bidirectionalflow_directiondescription
1-1reverse flow only
10flow in both directions
11forward flow only
0-1no flow
00forward flow only
01forward flow only

Short Pipe

is_bidirectionalflow_directiondescription
1-1reverse flow only
10flow in both directions
11forward flow only
0-1no flow
00forward flow only
01forward flow only