Getting started with OpenLB, lattice Boltzmann simulation code [On Demand 8]

[@AmiGanguli]

Thank you so much for these videos. I'm interested in researching more-or-less exactly what you're doing, and the entire TuxRiders series has been hugely motivational for me.

[@TuxRiders]

you're welcome man :). so glad to read this :)

[@LOMADAKARUNAKARREDDYRS]

Thanks for initiating tutorial platform for LB method

[@TuxRiders]

You are welcome :)

[@QuantumBeatsLab]

Thank you very much for the video. I am encountering a problem in the jpeg images not generating and I also tried with imagegick. The files that are generated are .matrix and .p files. can you please suggest on how to open it? Please reply

[@TuxRiders]

I think I need to reproduce the issue in order to see why this is an issue. you said you run this on WSL, right?

[@QuantumBeatsLab]

yes Sir@@TuxRiders

[@birsenerdem1]

Hi, first thank you for your videos. I have a question: Do you have additional information about the usage OpenLB for external flows like turbulent flows around an aircraft or wind turbines? How can I apply BCs to my case?

[@TuxRiders]

happy to know you liked the video. unfortunately, I don't have much knowledge about turbulent modeling using LBM.

[@topg3307]

Hello im new to the LBM simulators, i wanted to ask how can i implement stuff like pulsatile flow and moving boundaries, in custom made STL geometries on openLB (.OR.) palabos.

[@TuxRiders]

I'm afraid I've never done this, but I know that Palabos has a nice integration with IBM (immersed boundary), which should be technically possible to be used for this purpose. I don't know if there is a better approach for this. Sorry.

[@HoaiThanh-wm6ze]

when I copy the file to other folder and run it. it have error. it is no such file or directory. could you explain for that?

[@TuxRiders]

make sure to copy all the files. what you say is quite strange. did you manage to solve the problem?

[@idreeskhan-zp5ey]

Thank You for the efforts!

[@TuxRiders]

My pleasure :)

[@buseparlakk]

Can you solve the droplet based flow focusing microfluidic system with LB?

[@TuxRiders]

I have never done that, but I guess it should be possible :)

[@QuantumBeatsLab]

I have ran this using Ubuntu installed with WSL. The image file isnot comming . What is the issue??

[@TuxRiders]

install imagemagick and see if it resolves the issue.

[@creativelead3298]

Hello ,This video is very helpful.But i didnt understand How You use command of move but when i use this command(cygwin give option that there is no such directory ).Kindly tell me about this.

[@TuxRiders]

glad you liked the video. the mv command just moves the file to another directory (like ctrl+x followed by ctrl+v), so it shouldn't be an issue here. you may consider moving the file to a desired directory in Windows Explorer and then open Cygwin on that directory to continue.

[@QuantumBeatsLab]

Sir in the User Guide of OpenLB it is given that "There are two options of generating images of the processed values in 2D and 3D" which is Gifwriter and HeatMap. The cylinder2d has HeatMap in the code but its not generating the jpeg file. Any solution to this? here is that part of the code // Writes the vtk files if ( iT%vtkIter == 0 && iT > 0 ) { vtmWriter.write( iT ); { SuperEuklidNorm2D normVel( velocity ); BlockReduction2D2D planeReduction( normVel, 600, BlockDataSyncMode::ReduceOnly ); // write output as JPEG heatmap::write(planeReduction, iT); } { BlockReduction2D2D planeReduction( discretization, 600, BlockDataSyncMode::ReduceOnly ); heatmap::plotParam jpeg_scale; jpeg_scale.name = "quality"; jpeg_scale.colour = "blackbody"; heatmap::write( planeReduction, iT, jpeg_scale );

[@TuxRiders]

I've never faced this issue, but in my opinion, it should be relevant to imagemagick, which didn't solve your problem apparently, right?

[@ruyjunior8858]

Hi. Where I can find the algorithm that you used on cylinder in 2d?

[@TuxRiders]

hi. the algorithm used in OpenLB is standard lattice Boltzmann, so you can find the details of it in any book related to lattice Boltzmann method.

[@mjwei3819]

Thanks for sharing！

[@TuxRiders]

Our pleasure!

[@ashkanajrian830]

Your explanation covers concepts that anyone with a background in LBM and a quick 10-minute read of the OpenLB documentation would understand. I watched this video hoping for more specific details that I could apply to my real projects. Unfortunately, it didn't meet my expectations. Nevertheless, I wish you good luck.

[@TuxRiders]

sorry for disappointing you!

[@QuantumBeatsLab]

Dear Sir, I am writing this mail to you regarding the problem faced by me in compiling an OpenLB code according to one of your youtube videos titled "Getting started with OpenLB, lattice Boltzmann simulation code [On Demand 8]". According to your video you are able to generate the image files after the simulation but in my case only the "vtk" files are generated. I need to know is there any software I need to install to get the image directly or I need to add something to the code? Please help me with that. Thank you Regards Atanu Chaudhury Phd, NTHU

[@TuxRiders]

I think you don't need to add anything to the code. can you try to install imagemagick? it should be the missing component I guess. by the way, you can always use ParaView to export the VTK files to images.

[@QuantumBeatsLab]

thank you I will try that @@TuxRiders

[@QuantumBeatsLab]

thank you for your reply, I want to know another thing, how to make the Gnu plot. When I do the simulation a .dat file is also generated. Do I need any software for that to get the Gnu plot? @@TuxRiders

[@QuantumBeatsLab]

Sir the imagemagick is not able to open .matrix files. Any other solution to this????????????????@@TuxRiders

[@TuxRiders]

@@QuantumBeatsLab you need Gnuplot :). it's the name of a software.

[@stachjonas]

I was hoping for some description and explanation of the code and its creation. This seemed to me to be completely useless, everyone can see this for himself what he was explaining. I don't know how it was supposed to help.

[@TuxRiders]

Sorry for disappointing you.

[@stachjonas]

@@TuxRiders Sorry for my fluster, I'm flustered that in the video you keep saying it's very simple, but I don't understand it.

[@QuantumBeatsLab]

Sir can you please tell me how to calculate the Element numbers and the Grid point number from the OpenLB codes for example from Cylinder2D? As in Ansys we can find the Element number or Grid number directly but I didn’t find any such thing in OpenLB codes. Such as for Cylinder2D code I have estimated like this: Identify the grid resolution: The resolution N is defined as 200. The lattice length L is defined as 0.1/N. L = 0.1 / 200 = 0.0005 The length of the domain in the x-direction (lengthX) is 2.2. The length of the domain in the y-direction (lengthY) is 2.0. The number of grid points in the x-direction Nx = lengthX / L. The number of grid points in the y-direction Ny = lengthY / L. So, Nx = 2.2 / 0.0005 = 4400 Ny = 2 / 0.0005 = 4000 Total Grid Points = Nx * Ny = 4400 * 4000 = 17,600,000 Is it correct? Please help. @TuxRiders

[@TuxRiders]

I'm afraid I don't know how to get the element numbers in OpenLB. sorry.