11. Ouputs

Extracting data from CMUTS is exactly the same as is in normal OnScale models. For comparison with some of the typical experimental metrics the following points are useful to note:

  • Use POUT as normal
  • Extract the Drive Function for normalisation of FFTs in post-processing
  • Extract the out-of-plane displacement at the center of the membrane. A good measure of the peak deflection for specific input conditions
  • Extract Voltage and Charge on the active electrode. Allows for impedance curves to be created
  • Extract average displacement from the front face of the membrane. Good comparison with some laser vibrometry results and can be used to calculate pressure in a load analytically.
  • Extract average pressure a few elements from the front face of the device. Good for comparison with hydrophone measurements, and for calculating operating frequency.
  • Harmonic shapes can be extracted as normal via the shap command.
    pres aprs
    avrg ffydsp ydsp * regn $i1 $i2 $j4 $j4
    avrg ffpres aprs * regn $i1 $i2 $j4+10 $j4+10

    hist func                     /* drive function - 1
    histname electrode vq ctop    /* voltage and charge TOP electrodes - 2, 3
    histname avrg a all           /* average displacement on membrane - 4, 5 (disp, pres)
    hist ydsp $i1 $i2 1 $j4 $j4 1 /* thickness displacement on top membrane nodes - 6+