[paulpu318]

In twoPhaseEulerFoam, I want to use
"const twoPhaseSystem& fluid = db().lookupObject<twoPhaseSystem>" to get the dispersed phase, but it can not be compiled. the error is : ‘db’ was not declared in this scope const twoPhaseSystem& fluid = db().lookupObject<twoPhaseSystem>
^
I do not know why? Would you like to give me some suggestions?

[kebsiali]

not sure but try U_.db()

[paulpu318]

Originally Posted by kebsiali

not sure but try U_.db()

Thank you for your suggestions. I had used alpha1.db() in the expression, and the error message disappeared.But some other error messages appeared.
In fact, I want to add a viscosity model into the kinetic theory model, and it would use the drag force coeff. in the expression, which I do not know how to obtain. So I used the following methods which was used in derivedFvPatchFields,

const twoPhaseSystem& fluid = alpha1.db().lookupObject<twoPhaseSystem>
(
"phaseProperties"
);

const phaseModel& phased
(
fluid.phase1().name() == dimensionedInternalField().group()
? fluid.phase1()
: fluid.phase2()
);

volScalarField beta(phased.fluid().drag(phased).K());//obtain the drag coeff.

Now, the error is :
(1) error: ‘dimensionedInternalField’ was not declared in this scope;
(2) error: invalid use of incomplete type ‘const class Foam::dragModel’
(3) error: forward declaration of ‘const class Foam::dragModel’ class dragModel;

Would you like to give me some more suggestions on how to get the drag coeff.?
By the way, can you give me more explaination on alpha1.db().lookupObject<twoPhaseSystem>? how to understand the expression?