[Trilinos-Users] problem computing eigenvalues with Sundance
Andrea Penza
pepe.aero at alice.it
Thu Feb 2 13:39:10 MST 2012
Dear all,
I have been trying for days to solve the eigenvalue problem related to
Navier-Stokes equations in primitive variables using Sundance. Here is
the formulation that brings me troubles.
// --------------------------------------------------------
bool lumpedMass = false;
BasisFamily L1 = new Lagrange(1);
BasisFamily L2 = new Lagrange(2);
Expr ux = new UnknownFunction(L2, "ux");
Expr vx = new TestFunction(L2, "vx");
Expr uy = new UnknownFunction(L2, "uy");
Expr vy = new TestFunction(L2, "vy");
Expr p = new UnknownFunction(L1, "p");
Expr q = new TestFunction(L1, "q");
Expr u = List(ux, uy);
Expr v = List(vx, vy);
// U is the solution of main flow, previously computed:
Expr U = List(u0[0], u0[1]);
// Define the new weak form for the operator A:
Expr eqn3 = Integral(interior, (1/reynolds)*((grad*vx)*(grad*ux) +
(grad*vy)*(grad*uy)) + vx*(U*grad)*ux + vy*(U*grad)*uy +
vx*(u*grad)*u0[0] + vy*(u*grad)*u0[1] - p*(dx*vx+dy*vy), quad2 );
Expr eqn4 = Integral( interior, (dx*ux + dy*uy) * q, quad2 );
Expr eqnEig = eqn3 + eqn4;
// Define the weak form to build the operator M:
Expr massExpr = Integral( interior, vx*ux + vy*uy + 0.0*q*p, quad2);
LinearEigenproblem probEig(mesh, eqnEig, massExpr, List(vx, vy, q),
List(ux, uy, p), vecType, lumpedMass);
// -------------------------------------------------------------
The compilation of the whole code ends fine.
Trying to run the executable the system reports this error:
Sundance detected exception:
/home/andrea/Projects/trilinos-10.8.3-Source/packages/Sundance/src-core/InternalExprs/SundanceSymbPreprocessor.cpp:221:
Throw number = 1
Throw test that evaluated to true: e==0
Non-evaluatable expr Sum of Integrals[
Integral[
rqc=Integration Region
[6] cell filter=MaximalCellFilter
[6] quadrature rule=GaussianQuadrature[order=2]
[6] watchpoint=[]
expr=vx*ux+vy*uy
]
]
given to SymbPreprocessor::setupExpr()
test FAILED
Has anyone the idea of what could be the problem?
Thanks in advance for your support.
Kind regards,
Andrea
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