Data save error

NATALIA ALMEIDA
NATALIA ALMEIDA Altair Community Member
edited November 2022 in Community Q&A

Hi,

I have been a problem with the Data save interval of EDEM. I choose a target of 0.1s, but the simulation has been saving the h5 files in the interval of 0.0003s. Could anyone help me with this?

Best regards,

Natalia

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Answers

  • Stephen Cole
    Stephen Cole
    Altair Employee
    edited November 2022

    Hi Natalia,

     

    Are you using version 2017? I'd recommend using the latest 2022.1 version if so.  

     

    It seems like EDEM isn't picking up the 0.1 save time interval, i'd recommend adding this in again.  Using a , vs . for decimal point depends on the computer language pack but try both 0.1 and 0,1

     

    Regards

    Stephen

  • NATALIA ALMEIDA
    NATALIA ALMEIDA Altair Community Member
    edited November 2022

    Hi Stephen,

    Yes, I am using version 2017. 

    I've observed the files have been saving in the time step interval.

    As I was using 3e-5 as the time step, files have saved in the same interval. I changed for 4e-5 and the interval of files saving is 4e-5 now.

    But the target save interval hasn't been using by EDEM. I've tried to change several times.

     

  • Richard Wood_20774
    Richard Wood_20774
    Altair Employee
    edited November 2022
    NATALIA ALMEIDA said:

    Hi Stephen,

    Yes, I am using version 2017. 

    I've observed the files have been saving in the time step interval.

    As I was using 3e-5 as the time step, files have saved in the same interval. I changed for 4e-5 and the interval of files saving is 4e-5 now.

    But the target save interval hasn't been using by EDEM. I've tried to change several times.

     

    Hi,

    Are you using the coupling interface at all, or EDEM by itself?

    Richard

  • NATALIA ALMEIDA
    NATALIA ALMEIDA Altair Community Member
    edited November 2022
    Richard Wood_20774 said:

    Hi,

    Are you using the coupling interface at all, or EDEM by itself?

    Richard

    Hi Richard,

    I am using the coupling interface with ANSYS Fluent.

    I've noticed that if I reduce the time step to 1e-6, I can save the simulations in each 0,1s, as I need. If I rise the time step to 2e-6, although, EDEM starts to save every 2e-6s of simulation.

    I've been using EDEM 2017 for many years to operate CFD-DEM coupling, and this is the first time I've had this problem.

     

  • Richard Wood_20774
    Richard Wood_20774
    Altair Employee
    edited November 2022
    NATALIA ALMEIDA said:

    Hi Richard,

    I am using the coupling interface with ANSYS Fluent.

    I've noticed that if I reduce the time step to 1e-6, I can save the simulations in each 0,1s, as I need. If I rise the time step to 2e-6, although, EDEM starts to save every 2e-6s of simulation.

    I've been using EDEM 2017 for many years to operate CFD-DEM coupling, and this is the first time I've had this problem.

     

    That's the reason. When using the Fluent coupling essentially you're running a lot of small simulations and the data-saves are at the end of each Fluent timestep. That said I thought we had remedied this at some point in the past.

    Is this using the latest version of the coupling from the Community website?

    I just tested with EDEM 2021.2 and Fluent 2022 R2 with a Fluent timestep of 0.001 and a datasave of 0.01 in EDEM and I get 5 data saves. I would try with more recent versions of EDEM and Fluent and the latest version of the coupling (which I'll be updating shortly) as I remember this behaviour in the past but it has been addressed.


    Richard

  • NATALIA ALMEIDA
    NATALIA ALMEIDA Altair Community Member
    edited November 2022
    Richard Wood_20774 said:

    That's the reason. When using the Fluent coupling essentially you're running a lot of small simulations and the data-saves are at the end of each Fluent timestep. That said I thought we had remedied this at some point in the past.

    Is this using the latest version of the coupling from the Community website?

    I just tested with EDEM 2021.2 and Fluent 2022 R2 with a Fluent timestep of 0.001 and a datasave of 0.01 in EDEM and I get 5 data saves. I would try with more recent versions of EDEM and Fluent and the latest version of the coupling (which I'll be updating shortly) as I remember this behaviour in the past but it has been addressed.


    Richard

    I am using the latest version of the coupling.

    Now with a time step of 1e-6 in EDEM I don't have this problem, no matter the time step in Fluent... That's why I don't think the problem is the version of the softwares.

  • Richard Wood_20774
    Richard Wood_20774
    Altair Employee
    edited November 2022
    NATALIA ALMEIDA said:

    I am using the latest version of the coupling.

    Now with a time step of 1e-6 in EDEM I don't have this problem, no matter the time step in Fluent... That's why I don't think the problem is the version of the softwares.

    I can't remember if the changes were with the coupling or with EDEM or Fluent, but either way I would recommend using a more recent version of software if you can as there have been a lot of changes since 2017, including EDEM's coupling interface. I do recall seeing this issue in the past and from what I can tell it's no longer there.

    It could be to do with rounding of the timesteps, perhaps, so you could check to see how small deltas either side of your required timestep influence the saves, but I don't know what else to advise as I'm not seeing this with recent versions. 

    Richard

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