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Topics - LukeFire

Pages: [1] 2
PyroSim / New Smokeview user guide
« on: August 08, 2018, 07:55:51 am »
Hi there,

Is there a new smokeview user guide for the new smokeview results viewer? I believe the previous version is still available via the FDS documents page.



Never mind,

It is saved in the 'help tab' on the new results viewer instead of via the FDS documentation.

PyroSim / HVAC louvered vent - directional airflow
« on: May 31, 2018, 08:39:33 am »

I have previously been able to direct airflow in a specific direction using the method detailed in Chapter 17 of the Pyrosim User Guide (HVAC Vent section) and the same approach followed in section 9.2.7 of the FDS user guide.

I have not used this approach within this newer version of pyrosim and the previous method i thought i knew does not alter the direction of the airflow using any value. The outlet vent within my HVAC system is as follows:

&VENT ID='Out', SURF_ID='HVAC', XB=4.8,4.8,2.4,2.8,2.4,2.6, UVW=1.0,0.0,-0.5[/b][/b]/

I understand depending on the positioning of the vent, depends which values of the UVW to modify. I have used several values for the UVW however, when i examine the velocity slice file results the direction of the air flow does not change.

I am looking to direct the flow at a 25 degree downwards angle.

Any assistance would be appreciated.



PyroSim / Activation Controls
« on: March 19, 2018, 05:29:30 am »
Hi there,

I would like to report an issue identified whilst using the activation control function using multiple actions.

For example: I want to assign two separate obstructions ('Obs 1' and 'Obs 2') with two different timed actions (events).

I assign Obs 1 with two timed events i.e. Time (100s) Deactivate; Time (300s) Activate. I click apply and ok.
I assign Obs 2 with three time events i.e. Time (100s) Deactivate; Time (300s) Activate and Time (400s). This is developed by creating two separate controls.

If I re-review the obs 1 controls in the window it has overwritten the two time events and now seems to be assigned to the three timed events. However, if I review the two control functions in record view the parameters are correct and the Obs 1 has not been overwritten but it is shown incorrectly in the Pyrosim Activation controls window.

If the correct control is selected first, in the Activation Control’s panel, the correct multiple actions are displayed. It is only when selecting the control with the most actions first and then selecting the control with less actions to view that the issue appears (i.e. the extra actions are displayed where none have been created).

Let me know if anyone else has come across this issue.



PyroSim / Modelling Wind
« on: February 27, 2018, 09:22:49 am »
Hi there,

I am attempting to model the effects of wind within an open atrium, however, i am unsure if the results i am getting are correct.

I have followed the approach detailed in "Wind Method 1" within the FDS 6.6.0 user guide (Chapter 10). As the area i am reviewing is in a small built up town i am using the values of Z_0=1.0 which is suggested in Table 10.2. The information i have been given regarding the wind speeds etc. in the local area is 6m/s. I have specified the relevant information within Pyrosim, however, there is a large fluctuations of wind speeds from the base of the model to the top of the model i.e. height of mesh is 24m. The base of the model has a velocity speed of approx. <5m/s, however, at the top of the mesh (i.e. approx. 24m) the wind speeds are in the region of 30m/s. 

I understand that the default wind speed is taken at a height of 2m and if this is not the case you can set the Z_REF to the appropriate height. However, when i include the Z_REF (this has been confirmed to a height of 10m) i get an error message when in try re-run the model. The input values i have used within Pyrosim are as follows:

&WIND SPEED=6., DIRECTION=247., L=-100., Z_0=1.0 /

I include the Z_REF value after the Z_0 .... Z_0=1.0., Z_REF=10 / however, this does not work.

Can anyone provide me with any information regarding the Z_REF or if the other methods specified within FDS would be better suited.


PyroSim / Multiple Slice File Renders
« on: March 03, 2017, 09:29:49 am »
Hi there,

I am looking in to a way of developing or if there is something which already exists, that can produce multiple slice file renders within smokeview without the need for the user to manually develop this.

I have been working on projects which require literally thousands of images to accompany any CFD reports. However, i have previously manually done this and i would like to know if there is a way to pre-set specifc times, image settings, particular view points and input these in to specific co-ordinates in to a PDF document.

I understand you can render images in smokeview via certain amount of frames at a chosen view point however, we require specific time frames and these require to be set out in a certain way in a PDF document. 

It would be very helpful if anyone can provide any advise or recommendations without the need to simply embed videos.

Many thanks.

PyroSim / Time elapsed output file
« on: August 16, 2016, 05:23:50 am »
Hi there,

I wanted to ask a quick query regarding the actual recording of the models run time.

I want to make a note on how long previous models took to run. So i can make an accurate log of the run times of certian models.

I understand that if the model has fully, run to its pre-determined simulation time, FDS produces an output file with the relvant times of each time step attached to each relevant mesh, amongst a lot of other parameters.

At the bottom of the output file is:

"Time Stepping Wall Clock Time (s)" and "Total Elapsed Wall Clock Time (S)" i.e. the amount of time taken to run the model.

However, if i manually terminate a model this section of text is not produced. I can review what the last time step and how long it took to run the last step. However, i am not sure if this is correct, as previously i have terminated a model at i.e. 100 hours in to the simulation and the last time step is approx. 80 hours.

The question i am asking is how reliable is the time produced in the total elapsed time; and

How can i detemine an accurate run time if the time above is not produced?

This question is only based on models that have already been run.

Many thanks


PyroSim / Run FDS parallel processing
« on: June 03, 2016, 06:57:54 am »
Has anyone else has a problem running more than 1 model on the same machine using run FDS parallel?

I have two models i want to run using fds parallel however, only one model is allowed to run at a time.

The first one runs as normal and brings up the box stating which mesh is assigned to which MPI process and begins the simulation time. However, i attempt to run the second model (more or less identical models) and the box appears with 'starting FDS: C:\ program file \pyrosim 2016\fds\fds.exe ... and the time elapsed timer runs and nothing more.

I have terminated the first model, then tried running them the other way around and the second model runs fine and the first model does not begin either.

So the models are perfectly fine to run. However, it seems that the MPI function only allows one model at a time.

Can anyone provide any clarification on this issue.

Kind Regards,

PyroSim / CPU excel output file
« on: March 29, 2016, 10:18:31 am »
Can anyone provide me with any information regarding the CPU excel output file which is created in 2015-4-1214 version of PyroSim. What do the values represent etc.

Kind Regards


PyroSim / Error message
« on: February 24, 2016, 03:40:58 am »
Following on from my previous topic:

Another of my models this morning has terminated. However, this time i was able to retrieve an error message on the simulation run time tab :

op_read error on left context: Error = -1
unable to read cmd header on the left context, Error = -1
Error posting readv, an exisiting connection was forcibly closed by the remote host. (10054)

Can anyone enlighten me on this error message. 

Plus the time elapsed and time remaining is still running.

PyroSim / Long extended run time errors
« on: February 24, 2016, 02:18:52 am »
Has anyone experienced any computer errors whilst running models for a considerable amount of time.

I am currently running models and they have been running for approx. 150 - 200 hours. However, they keep shutting down around this time.

I ran run a full diagnostic check on the machines however, they do not come up with any reason to shut down and the Pyrosim model does not provide any error message relating to a problem with the model. 

The reason i ask is they have only done this when running the Pyrosim model over a period of 150 hours anything else they are running perfectly fine.

Just to note i am running the    PyroSim-2015-2-0604-x64-en.msi and the computers are set to never sleep etc.

Kind regards,

PyroSim / Error Version
« on: February 04, 2016, 10:40:45 am »
Can anyone be able to assist me with this error when transferring my model.

I have created my model on the (PyroSim-2015-2-0604-x64-en.msi) Version and i am transferring this model on to my modelling computers which is the exact same version of Pyrosim (PyroSim-2015-2-0604-x64-en.msi).

However, i am getting a error message appearing when i am trying to up load this model.

"Can not open (pyrosim file) The file was made with a new version of pyrosim.

But this is not the case both the computers have been installed on the same version.

Could anyone provide any recommendations?

Kind Regards,

PyroSim / mpiexec error
« on: January 18, 2016, 05:02:31 am »
I have updated to the latest version of Pyrosim (2015-4-1214-x64-em.msi)

I am having error messages trying to run models via Run FDS parallel.

I have read the release notes, which state that i may need to disable the Pyrosim MPI service installed by previous versions of Pyrosim.

Would this achievable via the Parallel Simulation (MPI) Problems section in the user manual on page 151.

I only ask because i have downloaded the latest version of Pyrosim on a separate computer and the only requirement to run a model via FDS parallel was to input the users password, which seems a lot simpler than having to go through command prompt....

Can you provide any assistance with this.

Kind Regards.

PyroSim / Video Capability
« on: July 29, 2015, 05:44:13 am »
Hi there,

Does Pyrosim have the ability to take a video or combined multiple snapshots of a model and play as a video?

Or if not, would you recommend any software with that capability.

Kind regards

PyroSim / Importing DWG/DXF File
« on: July 02, 2015, 04:12:49 am »
I am trying to import a DWG file and the dimensions are incorrect when imported to Pyrosim.

I have imported DWG files previously and usually the dimensions come up automatically, as what has been saved within the CAD or Revit files. (I have attached the a screenshot of the dimensions which come up). I have tried customizing the dimensions but no luck.

I have triple checked the dimensions within the CAD files are correct however, the issue stems when they are transferred in to Pyrosim. I have saved the DWG file to a DXF file however, this does not provide any dimensions at all, so unable to import to Pyrsosim.

I have double checked by importing a previous model i have done and that is fine. It is just this model.

Any ideas would be much appreciated?

PyroSim / Soot Yeild
« on: December 18, 2014, 09:30:27 am »
Just a quick question, this may have already been answered previously but i've only just got round to questioning it again.

Why has the default settings for the properties of a polyurethane fire changed to use the SFPE handbook instead of the NFPA guidance. 

Was this to do with the percentages of wood/polyurethane mix fires?.

This was a change from Version 5 to Version 6 FDS.

Kind regards,

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