a new forceModel

Hi CFDEMers,

I'm trying to create a new forceModel in CFDDEM. For example, forceModel Archimedes was changed a little bit to "StokesDrag". When running parCFDDEM, Error came out:

[1] Selecting forceModel StokesDrag

[1]
21

[1] --> FOAM FATAL ERROR:
[1] forceModel::New(const dictionary&, const spray&) :
unknown forceModelType type StokesDrag, constructor not in hash table

Valid forceModel types are :
(
[1]
[1]
FOAM parallel run aborting
[1]
KochHillDrag
MeiLift
scalarGeneralExchange
DiFeliceDrag
Archimedes
ShirgaonkarIB
fieldStore
fieldTimeAverage
ArchimedesIB
gradPForce
checkCouplingInterval
volWeightedAverage
virtualMassForce
particleVolume
particleCellVolume
LaEuScalarTemp
SchillerNaumannDrag
GidaspowDrag
noDrag
viscForce
interface
)
[0]
[0]
[0] --> FOAM FATAL ERROR:
[0] forceModel::New(const dictionary&, const spray&) :
unknown forceModelType type StokesDrag, constructor not in hash table

Valid forceModel types are :
[0]
[0]
FOAM parallel run aborting
[0]
[1] #0 Foam::error::pri

How Can CFDDEM know the new forceModel? what command should I use? Thanks

Regards,
yyu