ANSYS Fluent 3-Dimensional (3D) NACA 0012 Airfoil Turbulence Modeling Tutorial and Validation (2020)
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- Опубликовано: 4 окт 2024
- Hey guys, this is a follow-up to my 2-D tutorial. I do everything form importing points, Design Modeler, ANSYS Meshing, and ANSYS Fluent. An extra dimension adds a lot of complexities and can be much more computationally demanding. As a result it is sometimes best to use a turbulent model with wall functions that allows you to start at much higher y+ than 1. For design and meshing, I used body influence and inflation layers to resolve the viscous sublayers. I use the realizable K-Epsilon model with Enhanced Wall Function and it works well for the 0 and 4 degree AoA.
Initially, I accidentally set my reference area to 2m which is the chord length. In reality, the reference area should be chord length * spanwise length. In 2-D, the spanwise is assumed to be 1m deep, but in this 3D case the chord is 2m but the spanwise is 0.5. As a result, its the same reference area as the 2-D video. I still get pretty good results and when I re-did the results, in both CD and CL for these low AoA.
I had to change the velocities because although the reference areas are the same, the Reynolds numbers are not if they were at the same velocities. Reference area is m^2 while characteristic length is m (which as far as I have read is simply the chord length).
Let me know what you guys think.
I do not provide free homework help or troubleshooting of any kind beyond RUclips comments. However, if you are looking to get a bit of input or help on a project you can buy me a coffee and I'll respond: www.buymeacoff...
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21:26 bro this looks like a well detailed carpet
This looks amazing dude, I will try this model with my values when I get home from work!
Beautifully simulated and explanation.
@Anthony T Awesome work
Looking forward with your upcoming videos
Great work man thank you !!
Thanks for the Video, great learning. However, all these are tetrahedral elements. If you use Multizone with Hexadedral elements, the count could be much lower. However as per my knowledge, for a chord size of 300 mm at least 5 million elements are required.
hey @Anthony T , I noticed your 2D naca12 tutorial was taken down. I was using this to start my simulations for my final year project and now half way through I noticed your video is down. Is there any way you can share it?
what is the video link of creating this 3D MODEL IN FIRST 10 SECONDS OF VIDEO? CAN YOU please share
Hello,
Thanks for this video. I am studying the flow around a 3D wing and would like help with the reference values to be specified in Ansys Fluent. I know the area is the top surface of the wing, the length is that of the chord. But my problem is that the chord is not constant all the way down the wing (the chord at the root is bigger than the salmon one). How can I specify the chord in this case, please ?
Hi Anthony, thanks for the video - I have been trying to do something similar with a NACA0012 with chord of 0.3m and span of 0.9m. My first layer height is 0.0000172m which is greater than you specified in the video but I appear to be having trouble with that first layer height and orthogonal quality/skewness/aspect ratio. In your video - you do not seem to have these issues even though your first layer height is smaller, nor do you specify any curvature scopes for the aerofoil which I cannot seem to avoid. I'd appreciate any comments - thanks!
Hi, can you please make similar tutorial for vertical axis wind turbine
Hi Anthony, Really amazing video explaining steps involved from an engineer's point of view !!! What do yo think is approx. minimum RAM requirement for carrying out a 3d CFD Analysis like this one? 4 or 8 GB ?
There aren't much RAM requirements but i'd still probably recommend at least 8 GB of RAM for overall smooth operations
Thanks mate!
I cannot able to create two different sketches in XY plane. for body ofinfluence and boundary box...it is taking as one
Could you please explain about the connections. I deleted the contact but it still says on Fluent that I have a Solid and Airfoil Solid.
the connections help define interfaces which are important if you have moving meshes but if it says its a solid you might want to check your setting in the mesher to make sure you've defined the physics preference as "CFD" and solver preference as Fluent
Hi Anthony, I am trying to do my analysis and i done it similarly to the one start of your video. Could you tell me the location at which you added your decisions or if i could get a copy of that file would be great.
Thanks
Hi if you are referring to the meshing I did the each face exactly how I meshed the airfoil in my 2-D video but on the front and back face. I then connected the two faces with some non-biased edge sizings.
Thanks
nice video, may i know the paper you are using as a reference ? thank you
Hey Anthony, I hope you are doing well. I need some help with the ANSYS validation. How can i contact or reach you ?
hey man, your another video with NACA0012 was delated ? could you repost? It was very very helpfull
It should be back soon someone copyright claimed it so I’m sorting it out -_-
Hello, for some reason my velocity magnitude only shows all blue (0 velocity) across the aerofoil. Please help.
That's because near a wall, because of Viscosity between wall and fluid, the airfoil slows down the fluid and brings it to rest and at the airfoil surface it is basically not moving (0 velocity)
I used this tutorial to analyse NACA 4415 airfoil, but the orthogonal mesh quality reduced after adding inflation. what is the reason of this? and how can I avoid this?
This video talks about orthogonal mesh quality (ruclips.net/video/vgLSfbo0I0o/видео.html&feature=emb_title) You likely will have to remesh with small cells or tone down the inflation layers. There's always a trade off of computational resources and accuracy
At 21:30ish, how do you setup your bodies of influence and inflation layers (you skipped it out in the vid). When trying to set mines up I cant either select the bodies, or if I do select the bodies I cant select the correct options for the inflation layer
The "Geometry" is the overall body and the "Body of Influence" is the region you want defined more and the same goes for inflation
Hi Anthony, did you use a closed tail or a cut tail?
I believe this is a closed pointed trailing edge
@Anthony T Thanks, can you do some examples about wind turbine blade using CFD?
I’ve thought about them but they do take up a good amount of computational power if it’s properly done in 3D. I could probably do a 2D one in a few hours but I’ll think about it and maybe try it.
@@anthonyt6564 Thank you very much! If you want to simulate 3D wind turbine blade, I think the 3d blade model can scale 10 or 50 and so on. but you use 2d blade model to simulate wind turbine blade,i don't understand how to do this work. many thanks to reply!
@Anthony T why not use the C mesh at the front?
You could I just didn’t because I was lazy and showed it in the other video.
Hi Anthony, I’m a newbie who is trying to carry out the similar settings as yours. For the results at 0 deg angle of attack, it is comparable with the experimental data. However, the Cd is so inaccurate despite the acceptable Cl for high angle of attack (over 15 deg). Could you provide me some guidance for my case, please?
Thank you in advance,
Suphasin (Fame)
That's strange because that that AoA there should be separation and its pretty difficult for CFD to accurately capture that well. Cd is the result of proper resolution of the boundary layer so you may be using a poor mesh. You have the take into consideration the Y+ depending on your model so look into that. I use the K-E with wall functions which allow for larger Y+. Also check your reference values like what I had to corrent in this video.
@@anthonyt6564 Alright, I'll recheck the y+ and mesh resolution again. Then I'll let you know whether it works, thank you very much for replying my message!!!
Anthony T I improved the mesh and y+, the results are better!
p.s. another question: when I try to use the inflation function for 3d airfoil in structured mesh, it doesn’t work. The system always notifies that there is not enough memory. Do you have any suggestions for this case, please?
@@FameS15 hmm if it says there's not enough memory that means your computer ran out of RAM so maybe close everything else, but it should definitely be possible.
Anthony T There are 16 GB of RAM and when I tried it with unstructured mesh, it worked. That message only occurred when I applied the Inflation with C-H structured mesh. Some comments I found on the CFD community indicated that it was likely to be some kind of errors but no one provided the solution TT.
Hey.Are you going to make videos in Star ccm +
thnx
yeah, I'm planning on doing another star ccm video soon. Its a deflected airfoil I've tried in ANSYS and I just can't get it to work well so I'm going to do it in star
@@anthonyt6564 Thank you su much. Can't wait
@@anthonyt6564 can you do an example about wind turbine blade? thanks
How Can i get the dimensions for geometry?
I made the dimensions somewhat arbitrary. In reality you would want to domain size to be at least a magnitude wider than the length of the airfoil. As for the region of higher resolution, that is arbitrary but will need to be in line with inflation layers.
Hey, I guess I need your help how can I reach you?
@@anthonyt6564 solved the problem but also I am keeping your mail for future works, thank you so much by the way..
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too many words, too little useful info...