I'm trying to generate a steady-state Helmholtz simulation in a domain that contains a 3D plastic grid with 2x2 cells. I would like to understand how ultrasound wave at 40 kHz scatters through the object which has the wavelenght (0.0086 m) for height.
In the picture below we can observe 4 planes of the simulation in Paraview (-X,-Y,+X,+Y) and 2 perspective planes with the surface and wireframe. The domain is centred in (0,0) with boundaries [-0.0043, 0.0043] both in x and y.
I have been trying to set the ultrasound wave source with different configurations in Boundary Condition 1 (BC1) below (i.e. plane waves, constant pressure, variable coordinate dependence, etc). However, I cannot seem to get any different results by changing BC1.
Code: Select all
Boundary Condition 1
Target Boundaries(1) = $ inlet
Name = "In"
! Plane Wave BC = True ! Automatically sets the boundary conditions assuming outgoing plane waves
$p0=100.0
$k1=0.0
$k2=0.0
$k3=1.0
! Pressure Wave 1 = 100
Pressure Wave 2 = 0
Pressure Wave 1 = Variable Coordinate ! Coordinate variable dependence holds tx(0) = x, tx(1) = y and tx(2) = z
Real MATC "p0*cos(k1*tx(0)+k2*tx(1)+k3*tx(2))"
! Wave Impedance 1 = $ c0 !
! Pressure Wave 1 = 1
! Wave Flux 1 = Variable time; Real MATC "2 * pi * f * p * U"
! Wave Flux 2 = 0
! We want to save data at the inlet
! TODO how do we save data at the outlet
Save Scalars = Logical True
End
The project folder is here https://filebin.net/qosc3izc2qg2l9qr
Could anyone explain why the pressure distribution is not symmetric and how to make it simmetric in the Z axis? Is this a matter of setting plane waves correctly? How can I do it?
Also, I would like to try to input a complex pressure map to the simulation. How to do this?
Many thanks,
Francisco