Skip to content

Simulations & Solvers

FDTD, Low-Frequency, Neuron, Mode-Matching, Flow, Acoustics, etc...

251 Topics 759 Posts

Subcategories


  • FDTD, Low-Frequency, Neuron, Mode-Matching, Flow, Acoustics, etc...

    12 33
    12 Topics
    33 Posts
    brynB
    @viniltc, the error looks like you do not have a simulation called "Simple ES" (the returned simulation is None). Please double-check the name, including white-spaces. You can also access by index (document.AllSimulations[0]).
  • Subgrid for Acoustic Simulation, to limit grid size?

    2
    0 Votes
    2 Posts
    498 Views
    M
    There's no subgridding just a rectilinear / adaptive grid (you can create new grid settings and drag and drop solids or wireframes to these) What you can do (at your own 'risk') is manually set the grid to the resolution you want and not use the automatic grid settings. Typically you want at least 10 points per wavelength (more is better) and the wavelength in air (343 / freq) and water (1500 / freq) are quite different.
  • adding inductive decoupling circuits into the model

    1
    0 Votes
    1 Posts
    536 Views
    No one has replied
  • Pulse-Echo Ultrasound Acoustic Simulation Time Domain

    5
    0 Votes
    5 Posts
    1k Views
    M
    Don't worry about the time step, just make sure it's fine enough, Sim4Life will then interpolate your function into it's own timestep as needed (so, you just need to be careful that your timestep is not too coarse such that Sim4Life won't be able to linearly (I think) interpolate it Essentially, the answer is yes, its sufficient
  • SEFT Tutorial Grid Error

    8
    0 Votes
    8 Posts
    2k Views
    M
    Typically 1 MHz is way too large wavelength = speed of sound / frequency resolution = wavelength / 10 so, if you speed of sound in water is 1500 m/s and you want to run a simulation at 100 kHz, then the wavelength is around 15 mm, and the resolution should be at least 1.5mm From the resolution and your domain size you can calculate the grid size Grid Size: max. 20 Mio cells
  • Time domain acoustic simulation- problem with the number of periods

    5
    0 Votes
    5 Posts
    1k Views
    A
    @montanaro That would be of great help. Thank you so much Annalisa
  • SEFT simulation - problems with parameters

    10
    0 Votes
    10 Posts
    2k Views
    M
    I don't remember so well, but I'm pretty sure it's 1/timestep used to discretize / sample the signal. (Note that this is used to create a list of time points and pressure signals, but the acoustic solver then again reinterpolates this signal to it's own time step that is calculated from the Setup Frequency) Setup Frequency is mostly ignored now that you have user defined source, it was mostly used as a frequency of the sources and for the final FFT analysis. However, if I remember correctly it is used to calculate the time step used in the solver, so make sure it is set to the highest frequency available in your sources That expression was just a random signal to give the user an idea of how to input expressions. It seems in your case you want Element 5 to be sin(2 * pi * 0.5E9 *_t) and Element 6 to be sin(2 * pi * 0.75E9 *_t) if you want to excite one transducer at 500 KHz and the other at 750 KHz User defined sources sets an equation which is then sampled / interpolated at that sampling frequency (fs = 1/dt)
  • FDTD Simulation Fail

    2
    0 Votes
    2 Posts
    577 Views
    ofliO
    Dear Aiping, please send the simulation file to the support team. Thanks.
  • This topic is deleted!

    1
    0 Votes
    1 Posts
    2 Views
    No one has replied
  • Different frequencies in electrodes

    13
    0 Votes
    13 Posts
    4k Views
    H
    @pastis Hello, Have you solved this question? can we compare the amount of electric field that reach the targeted region to evaluate the TI simulation ?
  • Neuron solver failed

    2
    0 Votes
    2 Posts
    517 Views
    H
    Hello, It seems that you now have the Neuron installer and it is working, but something is missing in your setup. Could you please check for error messages in the Console? One possible reason could be that you have installed NEURON before Sim4Life completely finished its installation. Please uninstall Sim4Life, install it again, and only after finishing install NEURON.
  • RAM Usage Limit

    2
    0 Votes
    2 Posts
    579 Views
    H
    Hello, Unfortunately there is no direct way from Sim4Life to limit the amount of RAM to allocate for the program. You may be able to do so using external tools that tap into the operating system's settings and manage the resources. But we are not aware of any and we did not test any that we would recommend. The reason your PC is slowing down is because the OS switches to paging on disk instead of using fast RAM. Paging is slow and uses CPU resources. My guess is that even if you limit the RAM for Sim4Life, the solver will still need a lot more memory and it will either fail or use the disk for paging resulting in the similar slowing effect.
  • Magneto Quasi-static simulations stop

    1
    0 Votes
    1 Posts
    358 Views
    No one has replied
  • conformal mesh

    2
    0 Votes
    2 Posts
    503 Views
    brynB
    If the cable bounding box is smaller than the body, maybe you could use sub-gridding.
  • MPI only starts 1 process

    2
    0 Votes
    2 Posts
    566 Views
    H
    Hi @Pedro The FDTD solver does not make use of any CPU parallelization and is actually not very suitable for CPU computation except for very small simulations. It is strongly recommended to run FDTD on GPU to benefit from much higher simulation speeds.
  • EM LF solver: Symmetric vs Asymmetric Dirichlet boundary condition

    2
    0 Votes
    2 Posts
    528 Views
    SylvainS
    Hi, most likely you have some other boundary conditions that are affecting the solution. Please share a screenshot of your boundary condition settings, maybe there is a clue there.
  • Error in loading neuron model

    Unsolved
    4
    0 Votes
    4 Posts
    934 Views
    H
    How can I get the download code of neuro solver?
  • EM LF electro simulation

    1
    0 Votes
    1 Posts
    284 Views
    No one has replied
  • EM LF solving problem

    2
    0 Votes
    2 Posts
    485 Views
    H
    Hello, Could you please explain a bit more what you mean by two operations and different results. Please provide any data or screenshots that you think would help us understand the problem.
  • 1 Votes
    13 Posts
    4k Views
    H
    @christos1996 when I reach into the "Sensors" setting at Simulation Settings (Neuron)], the option "Point "Sensor Tool" is not available to click into. I am sure I have load the model. So have you solved this problem? how to solve ? hope you can reply me .
  • Correct time delay between transducers

    3
    0 Votes
    3 Posts
    696 Views
    M
    What do you mean with 'it is a real struggle' to calculate the phase? I used a python script for this. Would this be an acceptable solution? The idea is this (all in Python): Have a list of points indicating the coordinates of the base of the tranducer (can also be automated via Python) Interpolate the field values (complex values) of the reverse simulation at these points Calculate the phase of the complex value and conjugate it Create new simulation and add these phase values to the different sources of the transducer