[Kummi]

Hello Foamers,
Here is my code sample below.

if ((T_[cellI] == Tliq) && (alpha_[cellI] > scalar(0.0)))
{
QB_[cellI] = K_[cellI]* (T_[cellI] - Tliq) / DX.value();
/*
const Foam::List<int> neigbhorcellI = regionMesh().cellCells(cellI);
forAll(neigbhorcellI, I)
{
if (regionMesh().cellCentres()[I][0] < regionMesh().cellCentres()[cellI][0])
//if (regionMesh().X[I][0] < regionMesh().X[cellI][0])
{
//compute QB
QB_[cellI] = K_[I]* ((T_[I] - Tliq) /DX.value());
break ;
}
}*/

QBMAX_[cellI] = (Lboil.value()* (DX.value() - XB) *rho_[cellI] *alpha_[cellI] ) /dtime; //alpha

if (QB_[cellI] > QBMAX_[cellI])
{
QB_[cellI] = QBMAX_[cellI];
XB = scalar(0.0);
alpha_[cellI] = scalar(0.0); //alpha
}
else
{
XB = XB + ((QB_[cellI]*dtime) / (rho_[cellI]*alpha_[cellI] *Lboil.value())); //alpha
}
}

In blue highlighted QB_[cellI] equation, the values of conductivity (K_[cellI]) and temperature (T_[cellI]) are updated based on previous cell values. One of my well wisher suggested to use the code highlighted in Red commented out. But, this code doesn't worked out to access value from previous node.

Kindly someone suggest me how to access the value of K_[cellI] and T_[cellI] from previous node alone (not from all neighboring nodes).
Thank you

[Kummi]

Hello Foamers,
The discussion is about calculation of QBK here highlighted in blue. The image in the attachment gives clear overview. In the image, 2 cells are pictured with both cells possess its own cell centered node points. In cell 1, the calculation of QBK requires values of K_ and T_ from boundary cell (from wall) and in cell 2, the QBK calculation requires values of K_ and T_ from previous cell 1 (internal cells) and calculation prolongs among internal cells.


Below I have code written to extract values from boundary and internal cells. Code for boundary cell needed just for the calculation in NODE 1 alone, whereas code for internal cell prolongs inside the main domain for other NODES (from NODE 2 - till end).

How to adopt the phenomenon separately for boundary and internal cells based on QBK value?

if ((T_[cellI] == Tliq) && (alpha_[cellI] > scalar(0.0)))
{

//************ Code to extract value from BOUNDARY cell ************//
forAll (regionMesh().boundaryMesh(), patchI)
{
forAll(T_.boundaryField()[patchI], faceI)
{
scalar tK_ = K_.boundaryField()[patchI][faceI];
scalar tT_ = T_.boundaryField()[patchI][faceI];
QBK = tK_* (tT_ - Tliq) / DX.value();
}
}
//************ Code to extract value from BOUNDARY cell ************//



//************ Code to extract value from INTERNAL cell ************//
const Foam::List<int> neigbhorcellI = regionMesh().cellCells(cellI);
forAll(neigbhorcellI, I)
{
if (regionMesh().cellCentres()[I][0] < regionMesh().cellCentres()[cellI][0])
{
QBK = K_[I]* ((T_[I] - Tliq) /DX.value());
break ;
}
}
//************Code to extract value from INTERNAL cell ************//
QBMAXK = (Lboil.value()* (DX.value() - XB) *den.value() *alpha_[cellI] ) /dtime;
if (QBK > QBMAXK)
{
QBK = QBMAXK;
XB = scalar(0.0);
alpha_[cellI] = scalar(0.0);
}
else
{
XB = XB + ((QBK *dtime) / (den.value() *alpha_[cellI] *Lboil.value()));
} }

kindly someone share the thoughts.
Thank you