Thanks @kevinarden,
I do not believe that the X and Y components refer to the variables PW1 and PW2. According to
ElmerTutorials.pdf, section 17 (17. Helmholtz – 2D – Acoustic Waves – Air in a Cavity), they refer to pressure wave in the x-direction and y-direction.
Reviewing this forum topic
Acoustics – Basic Postprocessing With ElmerSolver & Paraview, I have tried to do it as follows with two consecutive simulations, modifying the solver.
For PW1 the solver would be:
Code: Select all
Solver 1
Equation = Helmholtz Equation
Variable = -dofs 2 Pressure Wave 1
Exported Variable 1 = -dofs 2 Pressure Wave 1
Procedure = "HelmholtzSolve" "HelmholtzSolver"
Exec Solver = Always
Stabilize = True
Optimize Bandwidth = True
Steady State Convergence Tolerance = 1.0e-5
Nonlinear System Convergence Tolerance = 1.0e-7
Nonlinear System Max Iterations = 20
Nonlinear System Newton After Iterations = 3
Nonlinear System Newton After Tolerance = 1.0e-3
Nonlinear System Relaxation Factor = 1
Linear System Solver = Iterative
Linear System Iterative Method = BiCGStab
Linear System Max Iterations = 500
Linear System Convergence Tolerance = 1.0e-10
BiCGstabl polynomial degree = 2
Linear System Preconditioning = ILU0
Linear System ILUT Tolerance = 1.0e-3
Linear System Abort Not Converged = False
Linear System Residual Output = 10
Linear System Precondition Recompute = 1
End
For PW2 the solver would be:
Code: Select all
Solver 1
Equation = Helmholtz Equation
Variable = -dofs 2 Pressure Wave 2
Exported Variable 1 = -dofs 2 Pressure Wave 2
Procedure = "HelmholtzSolve" "HelmholtzSolver"
Exec Solver = Always
Stabilize = True
Optimize Bandwidth = True
Steady State Convergence Tolerance = 1.0e-5
Nonlinear System Convergence Tolerance = 1.0e-7
Nonlinear System Max Iterations = 20
Nonlinear System Newton After Iterations = 3
Nonlinear System Newton After Tolerance = 1.0e-3
Nonlinear System Relaxation Factor = 1
Linear System Solver = Iterative
Linear System Iterative Method = BiCGStab
Linear System Max Iterations = 500
Linear System Convergence Tolerance = 1.0e-10
BiCGstabl polynomial degree = 2
Linear System Preconditioning = ILU0
Linear System ILUT Tolerance = 1.0e-3
Linear System Abort Not Converged = False
Linear System Residual Output = 10
Linear System Precondition Recompute = 1
End
The result is that in PW1 I get the same as in Pressure Wave, and PW2 is "0" in the entire domain.
With these results (PW2=0) I cannot apply formula 12.3 of the
ElmerModelsManual.pdf:
Code: Select all
p(t) = Re(P e^(iωt)) = Re(P) cos(ωt) - Im(P) sin(ωt)
Where:
- Re(P) is Pressure Wave 1
- Im(P) is Pressure Wave 2
The objective is to obtain p(t) at various moments of the simulation.
Any suggestions?
Thank you in advance for your help!
IsotoCedex