/// <summary>Complete mix tank model.</summary>
/// <param name="tank">Tank to be updated.</param>
/// <param name="dt">Step duration in seconds.</param>
private void Tankmix1(QualityTank tank, long dt)
{
// React contents of tank
double c = Tankreact(tank.Concentration, tank.Volume, ((Tank)tank.Node).Kb, dt);
// Determine tank & volumes
double vold = tank.Volume;
tank.Volume = tank.Volume + tank.Demand * dt;
double vin = tank.VolumeIn;
double cin;
if (vin > 0.0)
{
cin = tank.MassIn / vin;
}
else
{
cin = 0.0;
}
// Compute inflow concen.
double cmax = Math.Max(c, cin);
// Mix inflow with tank contents
if (vin > 0.0)
{
c = (c * vold + cin * vin) / (vold + vin);
}
c = Math.Min(c, cmax);
c = Math.Max(c, 0.0);
tank.Concentration = c;
tank.Quality = tank.Concentration;
}
/// <summary>2-compartment tank model (seg1 = mixing zone,seg2 = ambient zone).</summary>
/// <param name="tank">Tank to be updated.</param>
/// <param name="dt">Step duration in seconds.</param>
private void Tankmix2(QualityTank tank, long dt)
{
if (tank.Segments.Count == 0)
{
return;
}
QualitySegment seg1 = tank.Segments.Last.Value;
QualitySegment seg2 = tank.Segments.First.Value;
seg1.C = Tankreact(seg1.C, seg1.V, ((Tank)tank.Node).Kb, dt);
seg2.C = Tankreact(seg2.C, seg2.V, ((Tank)tank.Node).Kb, dt);
// Find inflows & outflows
double vnet = tank.Demand * dt;
double vin = tank.VolumeIn;
double cin = vin > 0.0 ? tank.MassIn / vin : 0.0;
double v1Max = ((Tank)tank.Node).V1Max;
// Tank is filling
double vt = 0.0;
if (vnet > 0.0)
{
vt = Math.Max(0.0, seg1.V + vnet - v1Max);
if (vin > 0.0)
{
seg1.C = (seg1.C * seg1.V + cin * vin) / (seg1.V + vin);
}
if (vt > 0.0)
{
seg2.C = (seg2.C * seg2.V + seg1.C * vt) / (seg2.V + vt);
}
}
// Tank is emptying
if (vnet < 0.0)
{
if (seg2.V > 0.0)
{
vt = Math.Min(seg2.V, -vnet);
}
if (vin + vt > 0.0)
{
seg1.C = (seg1.C * seg1.V + cin * vin + seg2.C * vt) / (seg1.V + vin + vt);
}
}
// Update segment volumes
if (vt > 0.0)
{
seg1.V = v1Max;
if (vnet > 0.0)
{
seg2.V += vt;
}
else
{
seg2.V = Math.Max(0.0, seg2.V - vt);
}
}
else
{
seg1.V += vnet;
seg1.V = Math.Min(seg1.V, v1Max);
seg1.V = Math.Max(0.0, seg1.V);
seg2.V = 0.0;
}
tank.Volume = Math.Max(tank.Volume + vnet, 0.0);
// Use quality of mixed compartment (seg1) to
// represent quality of tank since this is where
// outflow begins to flow from
tank.Concentration = seg1.C;
tank.Quality = tank.Concentration;
}
/// <summary>Last In-First Out (LIFO) tank model.</summary>
/// <param name="tank">Tank to be updated.</param>
/// <param name="dt">Step duration in seconds.</param>
private void Tankmix4(QualityTank tank, long dt)
{
if (tank.Segments.Count == 0)
{
return;
}
// React contents of each compartment
if (_reactflag)
{
for (LinkedListNode <QualitySegment> el = tank.Segments.Last; el != null; el = el.Previous)
{
QualitySegment seg = el.Value;
seg.C = Tankreact(seg.C, seg.V, ((Tank)tank.Node).Kb, dt);
}
}
// Find inflows & outflows
double vnet = tank.Demand * dt;
double vin = tank.VolumeIn;
double cin;
if (vin > 0.0)
{
cin = tank.MassIn / tank.VolumeIn;
}
else
{
cin = 0.0;
}
tank.Volume = Math.Max(0.0, tank.Volume + vnet);
tank.Concentration = tank.Segments.Last.Value.C;
// If tank filling, then create new last seg
if (vnet > 0.0)
{
if (tank.Segments.Count > 0)
{
QualitySegment seg = tank.Segments.Last.Value;
// Quality is the same, so just add flow volume to last seg
if (Math.Abs(seg.C - cin) < _net.Ctol)
{
seg.V += vnet;
}
// Otherwise add a new last seg to tank
// Which points to old last seg
else
{
tank.Segments.AddLast(new QualitySegment(vin, cin));
}
}
else
{
tank.Segments.AddLast(new QualitySegment(vin, cin));
}
tank.Concentration = tank.Segments.Last.Value.C;
}
// If net emptying then remove last segments until vnet consumed
else if (vnet < 0.0)
{
double vsum = 0.0;
double csum = 0.0;
vnet = -vnet;
while (vnet > 0.0)
{
if (tank.Segments.Count == 0)
{
break;
}
QualitySegment seg = tank.Segments.Last.Value;
if (seg == null)
{
break;
}
double vseg = seg.V;
vseg = Math.Min(vseg, vnet);
if (tank.Segments.Count == 1)
{
vseg = vnet;
}
vsum += vseg;
csum += seg.C * vseg;
vnet -= vseg;
if (vnet >= 0.0 && vseg >= seg.V)
{
tank.Segments.RemoveLast(); //(2.00.12 - LR)
}
else
{
// Remaining volume in segment
seg.V -= vseg;
}
}
// Reported tank quality is mixture of flow released and any inflow
tank.Concentration = (csum + tank.MassIn) / (vsum + vin);
}
tank.Quality = tank.Concentration;
}
/// <summary>First-In-First-Out (FIFO) tank model.</summary>
/// <param name="tank">Tank to be updated.</param>
/// <param name="dt">Step duration in seconds.</param>
///
private void Tankmix3(QualityTank tank, long dt)
{
if (tank.Segments.Count == 0)
{
return;
}
// React contents of each compartment
if (_reactflag)
{
foreach (QualitySegment seg in tank.Segments)
{
seg.C = Tankreact(seg.C, seg.V, ((Tank)tank.Node).Kb, dt);
}
}
// Find inflows & outflows
double vnet = tank.Demand * dt;
double vin = tank.VolumeIn;
double vout = vin - vnet;
double cin;
if (vin > 0.0)
{
cin = tank.MassIn / tank.VolumeIn;
}
else
{
cin = 0.0;
}
tank.Volume = Math.Max(tank.Volume + vnet, 0.0);
// Withdraw flow from first segment
double vsum = 0.0;
double csum = 0.0;
while (vout > 0.0)
{
if (tank.Segments.Count == 0)
{
break;
}
QualitySegment seg = tank.Segments.First.Value;
double vseg = seg.V; // Flow volume from leading seg
vseg = Math.Min(vseg, vout);
if (tank.Segments.Count == 1)
{
vseg = vout;
}
vsum += vseg;
csum += seg.C * vseg;
vout -= vseg; // Remaining flow volume
if (vout >= 0.0 && vseg >= seg.V)
{
tank.Segments.RemoveFirst();
}
else
{
// Remaining volume in segment
seg.V -= vseg;
}
}
// Use quality withdrawn from 1st segment
// to represent overall quality of tank
if (vsum > 0.0)
{
tank.Concentration = csum / vsum;
}
else
{
tank.Concentration = tank.Segments.First.Value.C;
}
tank.Quality = tank.Concentration;
// Add new last segment for new flow entering tank
if (vin > 0.0)
{
if (tank.Segments.Count > 0)
{
QualitySegment seg = tank.Segments.Last.Value;
// Quality is the same, so just add flow volume to last seg
if (Math.Abs(seg.C - cin) < _net.Ctol)
{
seg.V += vin;
}
else // Otherwise add a new seg to tank
{
tank.Segments.AddLast(new QualitySegment(vin, cin));
}
}
else // If no segs left then add a new one.
{
tank.Segments.AddLast(new QualitySegment(vin, cin));
}
}
}
