[CFD] Meshing Guide for Pipes and Ducts (O-grid, hexcore, polyhedra)

[@kauffman_47]

Wow, this video has been a game-changer for my doctoral thesis research! 🌟 Your clarity and depth of knowledge on the topic are truly impressive. Thanks so much for creating and sharing this invaluable resource with us. Your work is truly inspiring and a valuable contribution to the academic community. Keep up the great work! 👏👍

[@TheManolis1984]

Fantastic video on meshing. I have used polyhedral meshing for complex geometries (compressors, fan impellers) and I have to say I am blown away with the amount of time I can save per simulation, without sacrificing solution accuracy. I also use hexahedral meshing a lot and I very rarely use tetrahedrals anymore.

[@fluidmechanics101]

It is just so satisfying to get a solution with the same accuracy but with a smaller mesh. Faster solution time, faster post processing, smaller files. Everything is just so much easier 😊 People often focus on the smaller matrices and faster solution time, but in practice you set off a simulation and then forget about it. It is the faster loading times, faster post processing and smaller file sizes that really make life better!

[@simonrammel3464]

one of the BEST videos in the field, congrats - Simon!

[@laidmessaoudi5335]

All the questions are answered in this amazing presentation. Thanks a lot for sharing your experience.

[@sandipgewali641]

Loved it !! Need more meshing videos. This is neither taught nor found in an understandable way in textbooks.

[@tomofford9914]

Thanks Dr. A, your explanation of numerical diffusion was very enlightening. I've only seen this discussed before in the context of discretisation schemes and hadn't appreciated the importance of mesh alignment. I like both this style of video and the "first principles" style, they complement each other nicely.

[@fluidmechanics101]

Yep, people often forget the mesh!

[@sakurasuper]

thanks a lot for this meshing guide, it is really nice to have a complete overview of the different meshing approaches available. Meshing is a key element in cfd but it is often overlooked, because it can be tedious a time consuming. i would surely appreciate more contents on Ansa, like a step by step guide on how to achieve high quality mesh with optimal volume filling on a more complex/real geometry. Ansa seems really powerful but i am having trouble getting out of my meshing habits (i.e. triangular surface mesh > prism layers > tetra filling) !

[@darshangohel6873]

Amazing work, professor Aidan ❤️

[@romanskrasek2939]

Thank you for your explanation of the mesh diffusivity, now it seems clear for me. I am also using ANSA & META software in a daily basis. Regarding the topics which are in my wishlist, I want to ask you for the topics about FAN boundary conditions (OF, Fluent/StarCCM) and fans in cfd in general and then about the NVD ant TVD diagrams? These topics are not solved in YT and you are the man, who can do it (as always) as best🙂🌬

[@edwardagim7235]

best video on meshing I have seen. Thank you so much!

[@rafaortwein6646]

Super interesting. Practice with excellent theory, as the numerical diffusion is the best. Ideally videos with Ansys Fluent would be very interesting as well.

[@lfmantilla]

Thank you so much for sharing this type of content

[@samisri7188]

More! More! More! More! More!

[@redhotminipepper1]

Im afraid the audio is distorted Aidan.

[@nathansanchez3035]

^^ :(

[@fluidmechanics101]

How strange, I wonder why it distorted the audio. I will look into this and try and fix it. Sorry everyone!

[@francootaola9172]

Yes yes yeeees more videeeeos about meshing 😍😍😍 still waiting for a video in cut blocking 😁 (this would also be an awesome udemy cours!)as always great video man!

[@eig_himanshu]

Sir you are doing a great work!!

[@chathukawickramasinghe5532]

Thank you, the video is very clear!

[@delvonei]

Thank you very much indeed. Great and usefull video!! I loved it.

[@ChuYanWong-ob5xj]

Thanks Dr. Aidan for this useful video on this topic. Could you please share some experience on the sector meshing? Normally, what do we need to consider for meshing a sector of a pipe, I have found that the first cell at the bottom near the sharp corner, the quality is particularly bad. Thanks in advanced

[@fluidmechanics101]

If you are using ICEM CFD (block structured) you can use a 'Y block'. If you are using an unstructured mesh, you can fit a triangle into the corner. The key is to not make your sector too small. I would try and keep your sector angle at least 15 degrees. If your sector is any smaller, it is better to just use a 2D axisymmetric model.

[@uditsharmaification]

Absolutely incredible video, every concept was perfectly explained! I have one question however, why do we see (mathematically) numerical diffusion when the mesh is tilted/skewed? I can understand it intrinsically, but is there a mathematical explanation as well?

[@fluidmechanics101]

The mathematical explanation is in the book by Patankar 'Numerical Heat Transfer and Fluid Flow'

[@Toni999985]

Great video Aidan! Could you please make a video on solution initialisation?

[@NanoActuator]

Best of the bests

[@mahdikh1822]

Thank you for the very useful information in this video. Using O-grid meshing, it seems that the elements near the wall have high aspect ratio. Does it harm the accuracy of solution, especially when you have turbulence anisotropy?

[@fluidmechanics101]

That depends on your Turbulence model 🙂 For LES it definitely will, for RANS less so (but you can always do a mesh refinement study to check)

[@tmgi9123]

Excellent 🎉

[@ahmad.s94]

Thank you so much ❤ Please, could you make a special video on one of the topics: Phase change models, The porous media model, Combustion models

[@fluidmechanics101]

... all the difficult topics!

[@ahmad.s94]

@@fluidmechanics101 These are really difficult topics If you have enough time to talk about some of these topics, it will be very useful Thank you Dr. Aidan for all your efforts

[@EngrAly-qr6yg]

Excellent

[@Leo-cg4fe]

hi ! thank you very much for this video, it is very well explained ! what do you think about a radial mapping with a growth rate instead ? if I'm right the issue with numerical diffusion is non transverse to the flow meshing, radial meshing with prisms would not be an issue.

[@MusAbssiAbssi]

A very nice video thank you

[@Owningmovies]

Thank you very much! If I may ask, could you expand on why tetrahedral cells do not give better resolution? The way I picture it in my head is that if I have n points of information in a volume, greater n means greater resolution.

[@yashkaushik4992]

I have a very important question that I have trying to find the answer to in your meshing playlist. From what I see, the boundary layers are always hexahedral cells and its the volume cells that we chose whether to keep tet,hex,poly. My professor wants me to do the boundary layers also as polyhedral cells. This option is normally not there in OpenFOAM or Alter., is there a possiblity to use poly cells for boundary layers too. I know that when we double the cell size with each layer for square cell, one face of the bigger cell accomodates 4small faces so that is indeed polyhedral, but I am talking about the weirdly shaped poly cells.

[@felipeescalona4694]

HI, THESE VIDEOS ARE HELPING ME A LOT TO DO CFD ANALYSIS, AND MANY CONCEPTS THAT SUPPORT THE THEORY ARE VERY USEFUL IN THE DIFFERENT APPLICATIONS. I WOULD LIKE TO HAVE THE NAMES OF BOOKS THAT I CAN REFERENCE TO CITE THEM IN A THESIS PAPER.

[@fluidmechanics101]

You can cite this video 😎

[@jan-henrikrieger4661]

Very informative video, but I have one more question: What type of mesh should one choose when the diameter of the pipe varies along its length and also when the cross-section is not an ideal circle, but rather a jagged and wavy shape? Or can the presented meshes also be used for that purpose?

[@fluidmechanics101]

These methods should still work. You might need to try them out and check the cell quality / distribution of cells. It is hard to say ahead of time, but I suspect that they will all work (the block structured mesh may struggle and have worse quality cells in the core region, but I suspect the near wall region should be fine)

[@jan-henrikrieger4661]

@@fluidmechanics101 Thank you!

[@praneshdewangan]

Great one again, Aiden! i have a question about the number of inflation layers for internal flows. I watched your video about inflation layers and it clearly explains the method but for a fully developed internal flow, the boundary layer meets up in the middle of the pipe, in that case how many inflation layers should we consider? i am sure we should not take the pipe radius as yt. It would be great if you can clarify this. Thanks!

[@fluidmechanics101]

Great question. Normally for pipe flow we would look to try and get a smooth transition between the edge of the layers and the mesh in the core. This often results in the inflation layer thickness being ~ 20% of the pipe diameter. You are of course correct. Once the flow is fully developed, the boundary layer fills the entire pipe. We are just using the layers to try and increase the resolution of the near wall region, where the gradients are strongest

[@praneshdewangan]

@@fluidmechanics101 Awesome. Thanks man!

[@sergniko]

We want more! Just wondering if we made O-grid for core of O-grid would it be better in some way?

[@fluidmechanics101]

It probably wouldn't make that much difference. You could always try it and see what happens 😃

[@sergniko]

@@fluidmechanics101 writing a blockmeshdict file will be the hardest part of simulation :)

[@fluidmechanics101]

Yes! BlockMeshDict would be hard 😅

[@selimhandogan6693]

Is there any chance we can get a video about gap modelling?

[@alaaeddinelhemmali1370]

I wich if you do a complete comutional fluid course with codes for turbulence, I will buy it with what ever price

[@fluidmechanics101]

That sounds like a big undertaking! Maybe one day if I have the time 😅 for now, the SIMPLE algorithm course is pretty extensive and can get you most of the way there (it doesn't have a turbulence model in it yet)

[@ammarlaichi8474]

Hello Dr, what is the mesh suitable for simple circular pipe and circular pipe with circular corrugated in the inner wall?

[@edwardagim7235]

Do you have same video using ansys design modeler or space claim?

[@kanekanekun]

Great content! Does anyone have recommendations of free meshing softwares?

[@sandipgewali641]

Intro and Outro parts' audio seem robotic. Might need to address this issue in future videos.

[@tmh1759]

Early bundle course registration is closed on teachable? Nooooo

[@fluidmechanics101]

Yep it was only for the first month