Dear colleagues,
When we start CFD POST we receive this message:
" Note that for files other than CFX-Solver Results, global ranges are calculated for the used variables and the currently loaded timestep only. As more timesteps are loaded, global variable ranges are adjusted dynamically. Tip: To avoid dynamic range updates, you can use local variable ranges, or turn on pre-calculation of global ranges for all timesteps and all variables in : Edit>Options>CFD-Post>Files"
it means that for files other than CFX ( FLUENT for example ) we have to change dynamically the range of variables by going to Edit>Options>CFD-Post>Files and we check " Pre-calculate global variables ranges " .
in my unsteady simulation I have different time steps results and I want to show them , but when I follow the steps that I cited above in order to change dynamically the variables range for each time step it doesn't work and i got the same results for all the time steps !!!
Please if someone has encountered the same problem and has found a solution please help me.
Thank you .
My advice is that do not expect the software to do everything in one step. Sometimes you need to do your share of the work for complicated situations especially transient CFD. I suggest using a "unified" time step for all variables. Try also the similar tutorials.
The global range means the min and max for all transient simulation by default. Some times this boundaries are not representative of the mean values of some field. As example, imagine the velocity field with a unique volume with 100m/s and all the other around 1m/s. With the global range the colour contour will be next to blue and almost none variance will be noticed for each timestep.
Choose in the colour range of your contour the option USER DEFINED, and put the best in and max values for your data. Hence, it is possible see some variation around the mean values.
Options>CFD-Post>Files and we check " Pre-calculate global variables ranges " >
In my opinion this is a wrong interpretation of the message. If you go to Edit>Options>CFD-Post>Files and you check " Pre-calculate global variables ranges " the code calculate the global range over all the loaded time steps so you'll get fixed ranges based on the min and max encountered values; otherwise your range will vary in time (most of times this behaviour is not desiderable)
Thank you dear colleagues ,
maybe Mr. alesandro is right,
I'll try to be clearer, the problem I encounter with CFDpost is:
I have the results of an unsteady simulation (different Fluent files .dat for each time step), when I treat my results with Fluent is perfect. But I want to have other parameters on CFD post wich Fluent d’ont calculate like ‘' vortex strenght ' ' , but when I import the files .dat separately in CFD post I get the same results for all time steps, as if CFD post save the eurlier results even if we change the file .dat ( in Fluent it’s not the same because of the velocity changes with time and has waveforme) ... I think that there are steps to follow to avoid this problem.
please help me to fixe this problem ..
Thank you .
How did you import the different time steps?can you see them in the "timestep selector" in CFD post?Check if each result have different time looking at the Time variable in expression pannel.
Have you load different results ( a .dat for each time step) at same CFD post session? Or a single set of data that is the full transient simulation? CFD post can see new data such as an other case, and load separately for comparison purposes, e.g. two mesh refinement. hence, you could be seeing teh field for only one time step, the as other cases, and if is true, that is the mistake. In the importation there is the option ( load as single case) or similar thing, I do not remember now. verify if it is checked.
In Fluent there is a option (export top CFD post). The full data default is not always well interpreted for CFD post - designed firstly to CFX. The Fluent reading have some bugs for secondary or derived variables. The names does not match. The exportation, fix this misinterpretation.
Dear Ricardo , Alessandro and Osama
Sorry for my late reply and Thank you for your beneficial replies , exactly I should have to upload one of the data files and after that select one by one the others by using time step selector .
Best .
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