Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - stan_lw

Pages: [1] 2
Wind Engineering (WE-UQ) / Re: turbulentInflow mesh constrain
« on: November 11, 2021, 04:14:03 AM »
Seems like the case with fine mesh diverged due to large time step. The maximum Courant Number should be smaller than 1.0 for stability, but that case has a maximum Courant number of 2.46. You may try reducing your time step by 3 or 4 times.

Wind Engineering (WE-UQ) / Re: Unable to select pimpleFoam in WE-UQ
« on: October 23, 2021, 06:35:35 PM »
I downloaded the updated WE-UQ and it is version 2.2.0 now, pimpleFoam option is also available, issue solved, thank you.

Wind Engineering (WE-UQ) / Re: Unable to select pimpleFoam in WE-UQ
« on: October 22, 2021, 01:47:39 AM »
Mine version 2.1.0. I downloaded the application again from, but it is still version 2.1.0. As I am using Windows, I selected the "", the other one named "WE-UQ_Mac_Download.dmg" is for Mac OS I presume (see attached screenshot).

Wind Engineering (WE-UQ) / Re: Selecting version of OpenFOAM in WE-UQ
« on: October 22, 2021, 01:31:08 AM »
1) It is under "Code Implementation" in the Documentation

2) This is regarding the length scale issue in a previous post (, the check for negative converted length scale is implemented in OpenFoam v7 but not in v6.

Wind Engineering (WE-UQ) / Unable to select pimpleFoam in WE-UQ
« on: October 21, 2021, 04:56:06 AM »
The Documentation ( states that we can choose pisoFoam, icoFoam or pimpleFoam, but at the EVT Solver drop-down list, I can only choose either pisoFoam or icoFoam (see attached screenshot). How do we select "pimpleFoam" instead of "pisoFoam"? Thank you.

Wind Engineering (WE-UQ) / Selecting version of OpenFOAM in WE-UQ
« on: October 21, 2021, 04:51:28 AM »
Hi, I understand from the Documentation that WE-UQ has OpenFOAM v6 and v7. I run a test case, from the pisoFoam.log file, the line “/home1/apps/intel18/impi18_0/OpenFOAM/OpenFOAM-6.0/platforms/linux64IccDPInt32Opt/bin/pisoFoam -parallel” indicates that OpenFoam version 6 is used. How do I set the version of OpenFoam to v7 in WE-UQ? Thank you.

Wind Engineering (WE-UQ) / Re: TInFFoam freezes at first time step
« on: June 04, 2021, 04:48:44 AM »
To update, I recompile TInF with the updated source code and the issue is resolved.

Wind Engineering (WE-UQ) / TInFFoam freezes at first time step
« on: May 02, 2021, 01:59:53 AM »
I tried running the homogeneous tutorial case with turbulentDFSEMInlet. At the first time step, the output is as follow:

Starting time loop
Time = 0.025
Patch: inlet eddy box:
    volume    :4
    maxSigmaX    : 0.5

The simulation freezes after displaying the above message, with no further output. I will send the case file through email, thanks.

Hi, I tried to run the homogeneousTurbulence tutorial case with the turbulentDFSEMInlet boundary condition but the simulation cannot start with a missing keyword "delta". What is this delta? I cannot find it in the documentation. I will email the case file as it failed to upload here, thanks.

Wind Engineering (WE-UQ) / Re: Turbulent Inlet Flow for OF-8
« on: March 30, 2021, 09:55:20 PM »
I also think that it will be great if the turbulent inflow library can be implemented in OpenFoam v8, as some features in v8 (such as reading in Tables with non-uniform thermo-physical properties) are very useful.

To update, I did another test with an R table having all positive-definite R matrix. In fact, the original R table in the tutorial already have all rows being positive definite, excepts the four rows at the top and bottom of the domains, which have zeros for all values. I changed the values of R11, R22 and R33 to 1e-9 (a very small number but sufficient to make the R matrix positive definite) and rerun, but the simulation still crashed without starting.

To update on this issue, Jay suggests turning off “calculateU, calculateL and calculateR” by setting them to false. I tried that, but this does not work. In fact, the original tutorial case (which crashed) does not have these lines so by default they are false. If we turned them on (i.e, set them to true), then the simulation works because instead of looking for the tables in /constant/boundaryData/inlet, the simulation looks for /constant/inflowProperties file and skip reading the tables. I run a few tests to provide a clearer description of the issue:

1)   Set calculateU, calculateL and calculateR to false -> crashed
2)   Set calculateU, calculateL and calculateR to true -> cannot start because there is no inflowProperties file
3)   Set calculateU, calculateL and calculateR to true and add the file /constant/inflowProperties -> can run
4)   Set calculateU, calculateL and calculateR to false and add the file /constant/inflowProperties -> crashed

From above tests, the simulation works if it reads the file /constant/inflowProperties to obtain U, R, and L (“Specification via prescribed functions” method in the Documentation), but crashed if it reads the tables in /constant/boundaryData/inlet (“Specification via interpolation” method in the Documentation). So the issue lies with the tabulated data in the tables. Jay mentioned that the sigma tensor needs to be positive definite, I will play around with the values in the R table to check whether this is the root cause.

Wind Engineering (WE-UQ) / Filter factor in Digital Filtering Method
« on: February 22, 2021, 08:37:07 PM »
I have a question regarding the filter factor for the Digital Filtering Method. If I correctly understood the theory Section 1.3 (please correct me if I am wrong), N is the filter width and n is a ratio between a length scale L and grid spacing Δx, i.e., n = L/Δx. It is also mentioned that N should be chosen such that N ≥ 2n. However, in Section 2.2, Table 2.2 specifies that the filterFactor entry should be ≥ 4, i.e., N/n ≥ 4 or N ≥ 4n. Any reason why you implement a larger filter factor (N/n ≥ 4) than required by the theory (N/n≥ 2)?

Also, I think there is a typo regarding the definition of n, where n should be L/Δx (unit-less) instead of LΔx (unit of meter squared) in the documentation.

Hi Ajay,
Yes I have emailed Peter and he is looking into it, thanks

Sure we can discuss over Zoom, I will send you the updated case file with inflowProperties if you want to try whether you can reproduce the bug.

Pages: [1] 2