Reuse mesh in HFSS when changing only material properties

[ZiadHatab]

Hi, how can I reuse the same mesh from a solution in HFSS? The geometry is the same, I will only change the material.

[Samuelopez-ansys]

Hi @ZiadHatab,

You can use the method "add_mesh_link".

https://aedt.docs.pyansys.com/version/0.9/API/_autosummary/pyaedt.modules.SolveSetup.SetupHFSS.add_mesh_link.html

[ZiadHatab]

Thanks @Samuelopez-ansys for the answer.

mesh link works well when I do it manually through the GUI, but when I do it through scripting I get a different mesh (I compare the meshes of the two solutions in the mesh statistic window)

Here is my code:

import pyaedt
import numpy as np
import matplotlib.pyplot as plt

if __name__ == '__main__':
    
    #aedt_version = "2024.2"
    project_name = pyaedt.generate_unique_project_name(project_name='transmission_line')
    
    print("Project name " + project_name)
    
    hfss = pyaedt.Hfss(project=project_name,
                       #version=aedt_version,
                       design='microstrip',
                       non_graphical=False,
                       new_desktop=True,
                       solution_type='Modal',
                       close_on_exit=True,
                       )
    hfss.change_material_override(True)
    hfss.change_automatically_use_causal_materials(False)
    hfss.modeler.model_units = 'meter' 
    hfss.mesh.assign_initial_mesh_from_slider(applycurvilinear=True)

    # create material 
    isola_tachyon = hfss.materials.add_material('isola_tachyon')
    isola_tachyon.conductivity = '0'
    isola_tachyon.permittivity = '3'
    isola_tachyon.permeability = '1'
    isola_tachyon.dielectric_loss_tangent = '0.002'
    isola_tachyon.material_appearance = [64,128,128,0]
    isola_tachyon.update()
    
    # parameters
    line_length = 1e-3
    sub_height  = 0.1e-3
    trace_thickness = 0.02e-3
    sig_width = 0.24e-3
    sub_width = 4e-3
    port_height = 8*sub_height
    
    # draw the substrate 
    sub = hfss.modeler.create_box(origin=[-sub_width/2,0,0], 
                                  sizes=[sub_width,sub_height,line_length],
                                  material='isola_tachyon',
                                  name='SUB')
    sub.transparency = 0
    
    # draw the signal line
    sig = hfss.modeler.create_box(origin=[-sig_width/2,sub_height,0], 
                                  sizes=[sig_width,trace_thickness,line_length],
                                  material='copper',
                                  name='SIG')

    # draw the ground plane
    gnd = hfss.modeler.create_box(origin=[-sub_width/2,0,0], 
                                  sizes=[sub_width,-trace_thickness,line_length],
                                  material='copper',
                                  name='GND')
    
    # draw the port and assign wave-port
    port = hfss.modeler.create_polyline(points=[(-sub_width/2,0,0), (sub_width/2,0,0)],
                                        name='PORT').sweep_along_vector(sweep_vector=[0,port_height,0])
    P1 = hfss.wave_port(port, integration_line=[(0,sub_height,0),(0,0,0)],
                       modes=1, renormalize=False, deembed=0, 
                       name='P1')
    P1['Modes/Mode1/CharImp'] = 'Zpi'   # define characteristic impedance type
    
    # create air region 
    air = hfss.modeler.create_region(pad_value=[0,0,100,0,0,0], pad_type='Percentage Offset',
                                     name='AIRBOX')
    hfss.assign_radiation_boundary_to_objects(air, name='Radiation')
    
    # define simulation setup
    # first setup which we want to copy its mesh
    setup1 = hfss.create_setup('setup1')
    setup1.enable_adaptive_setup_single(freq='80GHz', max_passes=30)
    setup1.props['SolveType'] = 'PortsOnly'
    setup1.props['PortAccuracy'] = 0.01
    setup1.analyze(cores=4, gpus=1)
    
    # second setup "mesh-linked" to setup1
    setup2 = hfss.create_setup('setup2')
    setup2.enable_adaptive_setup_single(freq='80GHz')
    setup2.props['SolveType'] = 'PortsOnly'
    setup2.props['PortAccuracy'] = 0.01
    setup2.props['DoLambdaRefine'] = False
    setup2.add_mesh_link(design = hfss.design_name)
    setup2.props['MeshLink']['Soln'] = 'setup1 : PortOnly'

    # discrete sweep using sweep2
    f = np.arange(2, 110.1, 2)*1e9
    freq = f.tolist()
    sweep = setup2.create_single_point_sweep(unit='Hz', freq=freq, 
                                    save_single_field=False, save_fields=False, name='Single')
    setup2.analyze(cores=4, gpus=1)
    
    sol = setup2.get_solution_data(expressions='Gamma(P1)', domain='Sweep', 
                                  primary_sweep_variable='Freq', sweep='Single')
    gamma = np.array([complex(x,y) for x,y in zip(sol.data_real(expression='Gamma(P1)'), sol.data_imag(expression='Gamma(P1)'))])
    
    plt.figure()
    plt.plot(f*1e-9, gamma.real, lw=2)
    plt.xlabel('Frequency (GHz)')
    plt.ylabel('Alpha')    
    plt.show()
    
    '''
    hfss.close_project()
    hfss.delete_project()
    hfss.close_desktop()
    '''

These are mesh statistic result I get with script above. When I do the mesh link manually in the GUI and run the simulation, both mesh statistic agree.