Session 2: Smoke propagation in a parking garage


#1

Homework Assignment for Air-Conditioning and Ventilation webinar: Session-2

Step-by-Step

Import the project by clicking the link below:

Project Link: https://www.simscale.com/workbench?publiclink=9f5d8bb6-a473-447e-97da-d5cad68f5f81

Once the project is imported, the workbench is automatically opened.

Then follow the steps below for setting up a Steady-state Turbulent Scalar Transport analysis to simulate the smoke propagation in an indoor parking garage .

Mesh

In the Mesh Creator tab, click on Mesh Geometry to create a new mesh operation.

  • Select the Hex-dominant parametric (only CFD) Type
  • Give the shown number of cell in x,y and z directions for the bounding box
  • Select the number of processors for this meshing operation and Save.

  • Select _BaseMeshBox and Give the dimensions of the bounding box

  • Select Material Point and give the coordinates of material point. This point can be anywhere in the fluid region

  • Click on Mesh Refinements to refine the mesh at critical areas
  • Select the Surface Refinement. Give the level of refinement and give the surfaces to be refined

  • Add another mesh refinement. Select Feature Refinement and give required parameters accordingly

  • Now start the meshing process by hitting Start in Operation 1.

Simulation Setup

  • Move to the Simulation Designer tab and select Create New Simulation

  • In Analysis type, select the Fluid Dynamics and Passive Scalar Transport

  • Change the Turbulence model to k-omega SST and Steady State

  • To create the inlets, outlets and other faces, select Topological Entity Sets and then select the face you want to name and then click Create Set. Give appropriate name to the set

  • Set all the boundary faces as given in the image

  • To make the set for walls, first hide inlets and outlet by selecting one by one and clicking hide from Actions
  • Then Select all from selection and create set.

  • Select Model and give Simulation Model Properties accordingly

  • To assign the material (fluid) to the domain, select Materials import air from Import from Material Library and assign it to the fluid region

  • To set the boundary condition, right click Boundary Conditions and click Add boundary condition
  • Give boundary condition a proper name
  • Change the type of boundary to Velocity inlet and give the velocity accordingly
  • Assign the boundary inlets and click Save

  • Now again click Add boundary condition this time for smoke inlet
  • Set it to Velocity inlet and give the inlet velocity accordingly
  • Assign the smoke inlet face and click Save

  • Add another boundary condition for the outlet
  • Change the boundary type to pressure outlet
  • Assign the outlet face and click Save

  • Finally add another boundary condition for the walls
  • Change the boundary type to Wall, velocity No slip and Wall treatment to Wall function
  • Assign the wall faces and click Save

  • Click Numerics and change the [p] pressure solver to GAMG

  • Click Simulation control and set the parameters accordingly
  • Set the start time, end time = 2000 and write control of simulation
  • Select the number of processors for this job

  • Click Simulation runs and click Check to check if all the requirements for the setup are fulfilled
  • Now click New to create new simulation run
  • Click Start to start the simulation run

Post Processing

  • Move to the Post Processing tab
  • Click on the Solution field
  • Select the field you want to plot
  • Select the last time step to see the steady state solution

  • To add slice click on the solution
  • Click Add Filter and select Slice from options
  • Set the slice origin and axis details accordingly
  • Now add more slices by repeating the same steps this time normal to y direction and give proper origin (translate in y direction if needed)
  • Set the field T1 to plot smoke distribution

  • To plot velocity select the slices on by one and change the field to velocity
  • If needed Rescale the results

That’s all for the assignment !

Feel free to post your questions and results for discussion.


Community Digest July 2016
#2

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#8

Could not attend the webinar but very interesting simulation! Enjoyed it! :slight_smile:


#9

Hi @jousefm,

Thanks for sharing the results.

We will soon post the Webinar Video in the forum.

Best,
Ali.


#10

Interesting topic!!!

Luca


#11

Great work @jousefm, @l_trefiletti!


#12

I didn’t get an email that the step-by-step instructions online. I hope I will get the reminder when he next webinar will be.


#13

Hello all,

I am a new user to simscale and I was trying this simulation.

  1. I ran 2000 iterations. but I want to run more iterations and continue the simulations. How can I do that? There is no option to change the initial solution.

  2. Also, during post-processing, are smoke concentration plots called T1 plots ?

Thanks for the help.:smiley:
Abhishek


#14

Hi Abhishek (@averma),

Welcome to SimScale :slight_smile: To answer your questions,

  1. If you would want to run more time steps that’s possible only by starting the simulation again from the beginning, with the preferred End time value option under Simulation Control.

  2. Yes, T1 gives the smoke concentration. During Analysis type definition of this simulation we define the number of passive transport species to be 1. Hence T1 is the corresponding scalar.

Best regards,
Sam (@sjesu_rajendra)


'AC-Ventilation Session2 HW - Smoke in a Parking Garage' simulation project by varsey
#15

@sjesu_rajendra
Thanks a lot!!


#16

@sburger, the reminder for the new homework + recording indeed came a bit late (troubles processing the recording) but in the meantime you should have received it, right? Next time this will come again earlier again.


#17

Hi everyone!

I had a problem with the mesh generation doing exactly as tutorial says. Meshing process created a walls mesh, not the volume inside the garage mesh. So I had to move materialPoint aside from the center and now it’s ok.

Hope it helps those who will do this tutorial in future.

Also I did a little research on numerics config setup influence on the results and one more additional simulation using refined mesh. If you interested you can see project here.

Thanks for webinar.


#18

Hello everyone and thanks for the webinar and also for the step-by-step doc. Very useful! :slight_smile:

Unfortunately I had to leave the webinar before it finished and now I’m trying to catch up with the video and the step-by-step process.

I have a doubt about the hypothesis of the case.
We are setting the air and smoke inlets as “Velocity Inlet” and the outlets as “Pressure Outlet” @ 0 fixed value.
Does it mean we are supplying air and smoke, but we are not extracting them, so the mix of air and smoke makes its way to the outlet due to the pressure in the room? (Fans only blowing inside. No fans extracting)
What would be the right settings to simulate fans blowing fresh air in and fans extracting the contaminated air out of the room?

Many thanks!
Sergio


#19

Hello Sergio (@kzacck),

Fan outlet boundary condition can be defined as follows.

The fan pressure value should be defined using a .csv file upload, characterized by the fan curve properties.

Regards,
Sam


#20

Sam @sjesu_rajendra ,
Thanks a lot for the accurate and detailed answer.
I’ll give it a go as soon as I can! :slight_smile:

Regards.
Sergio