double getModPumpFlow(int i, double q, double dt)
//
// Input: i = link index
// q = pump flow from pump curve (cfs)
// dt = time step (sec)
// Output: returns modified pump flow rate (cfs)
// Purpose: modifies pump curve pumping rate depending on amount of water
// available at pump's inlet node.
//
{
int j = Link[i].node1; // pump's inlet node index
int k = Link[i].subIndex; // pump's index
double newNetInflow; // inflow - outflow rate (cfs)
double netFlowVolume; // inflow - outflow volume (ft3)
double y; // node depth (ft)
if ( q == 0.0 ) return q;
// --- case where inlet node is a storage node:
// prevent node volume from going negative
if ( Node[j].type == STORAGE ) return node_getMaxOutflow(j, q, dt);
// --- case where inlet is a non-storage node
switch ( Pump[k].type )
{
// --- for Type1 pump, a volume is computed for inlet node,
// so make sure it doesn't go negative
case TYPE1_PUMP:
return node_getMaxOutflow(j, q, dt);
// --- for other types of pumps, if pumping rate would make depth
// at upstream node negative, then set pumping rate = inflow
case TYPE2_PUMP:
case TYPE4_PUMP:
case TYPE3_PUMP:
newNetInflow = Node[j].inflow - Node[j].outflow - q;
netFlowVolume = 0.5 * (Node[j].oldNetInflow + newNetInflow ) * dt;
y = Node[j].oldDepth + netFlowVolume / Xnode[j].newSurfArea;
if ( y <= 0.0 ) return Node[j].inflow;
}
return q;
}
double getLinkInflow(int j, double dt)
//
// Input: j = link index
// dt = routing time step (sec)
// Output: returns link inflow (cfs)
// Purpose: finds flow into upstream end of link at current time step under
// Steady or Kin. Wave routing.
//
{
int n1 = Link[j].node1;
double q;
if ( Link[j].type == CONDUIT ||
Link[j].type == PUMP ||
Node[n1].type == STORAGE ) q = link_getInflow(j);
else q = 0.0;
return node_getMaxOutflow(n1, q, dt);
}