Use CFD to take your 3D printed designs to the next level - for free!
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- čas přidán 7. 07. 2024
- CFD (computation fluid dynamics) is essentially a virtual wind tunnel test. In the past, a really powerful computer was needed to crunch the simulation in a timely manner. These days, we can use cloud based software such as Simscale. Best of all, it's completely free for enthusiasts.
In this video, I take you through an example tutorial where a part cooling fan duct is optimised for a 3D printer. I'm not an aeronautical engineer, but what is here should be enough to get you going. There is a lot of documentation, but much of it is out date, incomplete or hard to find. Hopefully this video can help overcome this.
Simscale: www.simscale.com
Airflow calculator: www.engineering.com/calculato...
Models and simulations shown in this video:
Little jet plane: www.thingiverse.com/thing:222309
Petsfang part cooling fan duct: www.thingiverse.com/thing:275...
Thermal analysis by Aravindbaskar: www.simscale.com/workbench/?p...
Super layer cooler CFD by Haabilo: www.simscale.com/workbench/?p...
Infill type strength comparision for 3D printed parts - Static FEA by jhorv_th: www.simscale.com/workbench/?p...
Part cooling fan duct optimized with nozzle by mgrimm: www.simscale.com/workbench/?p...
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I'll be honest. My designs will never have a need for such a program but I viewed your entire video just to hear your detailed explanation. You're a very educated individual and a definite gem to have in the community!
Who knows. Mabye you could make use of the FEM module of SimScale in the future to test your design before you actually print/build it :)
Talking about CFD and 3D printing while wearing a RedBull Racing shirt... I think I just found my new favorite channel!
Love your videos! As a PhD student doing lots of CFD work, I'd caution that CFD is not that simple - a lot of concepts are needed to get accurate results. I've spent hundreds of hours learning these, and I still feel completely in the dark. At velocities this high, turbulence modeling will be crucially important, not to mention meshing - I've spent tens of hours designing the mesh for a lower-velocity flow than this. I hope the program automatically chose a turbulence model behind the scenes - and even if it did, turbulence modeling is far from one-size-fits-all. It probably chose k-epsilon, which is a weak, time-averaged model. A small tweak to setup can make large differences in results, so it's important to verify a CFD run against known results. Intuitively, a 5015 blower causing peak velocities of hundreds of meters per second seems unlikely. This could be from bad CFD, or it could be from the assumption that the blower is pushing its open air flow rate at these backpressures. If you multiply average inlet pressure (in Pa) by average inlet velocity (in m/s), you'll get power. I'd be willing to bet that exceeds the fan's electrical draw, which is physically impossible.
All that to say - the average Joe will probably get cool looking results from this. For very low-velocity, simple flows, you might even get useful results. But for high-Reynolds number, turbulent flows like this, it takes a lot of knowledge to get good data.
I agree with you, this results are not trust worthy. It is highly unlikely to have inlet 7m/s and end up with supersonic flow. The usage of compressible flow solver in the first place is questionable. Having said that, I found it a very good tutorial for many people.
Thank you for your input and giving the disclaimers. It's good not to get overly confident with these things.
This is what you call colorful fluid dynamics :D thanks for the explanation! It's cool that this free tools exists I'm sure you could refine it but as always GIGO.
@@tsslaporte Ha, colorful fluid dynamics. I'll have to tell my advisor that one! And of course, garbage in, garbage out!
@@hk318i I thought the compressible solver to be pretty questionable too. It wouldn't be too hard of a calculation (if I could remember the formula) to find the choke pressure of a duct this size - I'm sure it's far in excess of what this fan can provide. IIRC, it took around 80psi to get an air compressor blower nozzle (so, a few mm in diameter) to choke. Of course, you can have compressible flow below M=1, but that would be an easy idiot check for the results.
It would be great to have an updated video for Simscale. Their UI has changed a bit, to a point that it takes a bit of guess work to get a CFD simulation running. I'm currently working on a new nozzle idea for the part cooling on the Ender 3 V2 Neo. The hardest part for me was figuring out how to get the internal flow volume "open inner region." This is now done in the built in CAD editor. You still need everything setup the same way. The new command is flow volume>internal. The options have changed order, so your first selection is the small inside edge for the seed. Then, select the outer faces for boundary faces. After letting the volume create, then you have to delete the solid bodies you brought in from your CAD software, so that only the flow volume remains. Last, export this into the simulation setup. Without exporting, the changes stay in the CAD environment, but are not applied to the model in the simulation setup. It will appear as a cope of the original geometry in the list of geometries. Then, select the newly created geometry, and start a new simulation. Everything else is about the same as in the video. Be sure to pay attention to what's pressure and what's velocity,
They've also removed compressible flow analysis from the free community plan.
Thank you :)
You should have used a proper turbulence model instead of laminar.
The flow coming out of a fan (whether radial or axial) is highly turbulent, if you are simulating flow after an axial fan, I'd suggest k-epsilon RNG model with proper wall functions.
If radial fan, k-epsilon Realizable or k-omega model could be suitable.
Also, keep in mind that the rotational moment after the fan could have a very big impact on the flow downwards. (which means at least some kind of rotationary momentum should be added into your inlet boundary)
r/vxjunkies
Came here to say exactly that!
True & SimScale offers both turbulence models fortunately :)
Well, what do you mean it is a turbulent model? Do you mean that appeared vortexes? The laminar flow can be justified if it fits the Reynolds number below 2100. As examples, the von Karman vortex can be solved using a laminar solver as well. I can assure you that you will get the vortexes and it does not need a turbulent model as long as Re is below 2100. However, as many people agreed the CFD simulations are not that simple. In addition, as you said the mesh has to be well chosen and made. Actually, the mesh is the state of the art itself in CFD. The CFD software lately becoming more and more user friendly, however, without the CFD engineering background in fluid mechanics can lead to wrong conclusions.
This really is pretty awesome! I didn't even realize there was free software out there like this! Looks like im gonna be busy for the next... Forever, lol!
Thanks Micheal. Really appreciate the effort you put in to your videos and the emphasis you put on giving back to the community! it truly is amazing what we can do when we work together towards a greater good!
Great video as always. I've already run through a couple of simulations for fan ducts I've designed on my printers in the past. Really enlightening, and way easier than doing the smoke test I used to do when designing ducts. Your channel is always so informative and easy to follow along. Keep up the great work.
This content is excellent. Probably the most useful 3D printing channel on YT! Thanks!!
Hobby CFD: take some coloring pens and just draw your own stream lines ;) don’t forget wall treatment and boundary layer, turbulence close your eyes and continue drawing ;)
This has got to be the freaking coolest website I've come across in years! Thank you for sharing this
This is incredible! I was just thinking how handy it would be to have a basic, hobbyist cfd program. One thing you can do to make your sims run faster is to take advantage of symmetry. Basically, cut your models in half before exporting and then make sure the fluid doesn't exit through that face.
Thanks for this! It's amazing that these types of tools are available for free.
Spot on man, thanks for the video. This is exactly what I needed since I am in the process of making new fan ducts for my setup and experiencing problems with airflow.
Ah Navier-Stokes, my good friend.
"Hello darkness my old friend...." - what most people think when they see NSE.
Thanks for making this video! I'm designing a smoke collector for a laser cutter - basically a part cooling fan in reverse. I figured I could find some people talking about using CFD for designing part cooling fan ducts, but I didn't expect it would be you! I realize the CFD will be optimistic at best, but it will still help point me in the right direction if I'm doing something obviously stupid.
As I have made a (pretty simple) fan design for my printer, which I am currently using, but am having trouble with the cooling on the back side, this is definitely something I will look at! Thanks Michael.
HOLY SHIZZEL! How did I miss this video when it came out?! I was already a subscriber but found this video searching about CFD.
Great video. I have just started getting into modeling cooling ducts and this is just what I need to check and improve my designs.
Another great vid. Thnx Michael. Would love to see a basic modeling video. Ive tried a few times to learn but ultimately get frustrated. The way u explain things i feel it could help a lot of people.
CFD is quite complex. there are many factors to be taken into account. but it may give somehow a good estimation of flow direction and speed. If you go deeply you will realize that there are so many maths involved and good understanding of advanced flow equations are needed to get good estimations. For anyone getting inside CFD try to read the basics at least to know what you are doing.
thank you :) i was trying to simulate this last week unsuccesfully. Thanks to you i did it :)
This is excellent timing. I just got my hands on a ARRMA Limitless RC car and planning to do some experiments with some wing designs.
Wow that's an amazing free resource. I need to make a dust extraction port for my surface grinder this could really help to optimise it.
You’re awesome. Thanks for your clear structured and informative videos
This is exactly what I'm looking for after I scan my car. Can't wait to try it.
Good stuff. I wish more people would use this type of thing to design parts cooling ducts. I've downloaded some pretty dodgy designs for my ender 3 before settling on one that was actually properly CFD optimised and it makes a world of difference when you don't have crazy amounts of flow restriction going on.
Defintely adding this to my toolkit
Months ago i jumped at the chance! It was from one of the High School Racer videos when you mentioned it.
Thanks for the great walkthrough.
I'd love if the F.E.A And Thermal Design components could be covered on the channel too.
gosh damn it I wish I found this video a year ago! Thanks so much man!
That's fantastic, I am an avid F1 fan and am trying to design the Mercedes W08 aero package to fit onto a 3racing FGX. It's a lot more aesthetic than functional, but it will be interesting to see what parts look like when stuck in this kind of CFD software
this is cool! kinda wanted to do this with my Hamera parts fan ducts.. gunna have to give it a try !!
The best channel!
Should these simulations include a flat surface directly under the nozzle, to simulate printing close to the bed or top layers, if you print things that are flat?
Fantastic video, well done, and thank you.
The compression flow is now part of the pro subscription, and not given for free.
I've been struggling beyond that, because their interface has changed. Where you create the flow region, there's now a separate cad editor so the right click option isn't there. Then it doesn't seem to react the same way and give me a flow region like yours - mine seems to be "inside" the solid volume that I modelled in, and I can't fathom that out. I keep getting a message about it being an invalid set-up, but it isn't really telling me why.
Hi Michael, thanks for a very clear explanation. I’m inspired to model my Pajero tow vehicle attached to my caravan in an effort to analyse the best angle of attack of my purchased wind deflector for best effect. Hoping to find best location and angle to give optimum downforce without too much drag.
Thanks again, Pete
Interesting video as always
New approach, love it
Thanks for sharing👍😀
Thank you for another great video!👍
Thank you for another great video!
Great video, younger student me would have for sure enjoyed to learn by using these tools. I bet they love these lessons you teach! But I am also amazed by the amount of people commenting about turbulence models etc. I think it is kinda besides the point of the video, which seems to be introducing a free tool that anyone can use for doing hobby projects (which by the way is amazing, free tools for cfd are quite rare).
And to all these wikipedia warriors in the comments: To begin with, the K-Epsilon that everyone is yelling in the comments is not a good model especially for curved surfaces and high turbulence simulation... It's just very fast for finding basic flow patterns, but handles near wall badly and is overly diffusive... For the simulation shown in the video if you want to stick with RANS models, a SST K-omega would probably be the way to go, but would need a bit more understanding of the case before saying for sure. If the case is not a steady state (which I think it is not since the two flows are pointing at each-other), even SRS model could be considered instead, if it is important to correctly simulate the flow around the nozzle.
The fan duct on my Reliabuild3D printer was designed by an engineer who works with fluid flow all the time at Flowserve. It is simple without any crazy bends (thing:3056162 on Thingiverse). It makes it look strange because the fan is hanging way out in the front. You want to get the air in and out quick. The 2 sided or all around airflow can slow down the incoming air from the other side.
This is awesome! Thank you for putting this up... I've wanted a way to get familiar with CFD without a lot of software/programming learning along the way. This makes it SO much more accessible. Thank you! By the way, wouldn't an incompressible assumption be ok for such a low pressure simulation since the mach numbers involved are negligible? I guess I'll have to try one and compare results!
Please more videos like this!!
Nice video! Would love to see an explanation like this for openfoam
Excellent content!
Fyi unless your air flow is above 0.5 Mach or so, compress-ability effects in air are pretty minor. Should save you some core hours by using an incompressable simulation instead.
Wait so you're telling me the airflow isn't supposed to be at Mach 0.5 for 3D printer fans?
@@hudsonr.218 Mach 0.5 or faster cooling air would help when pushing for extreme speeds. I.e. >400mm/s and >10,000mm/s^2. But most cooling fans don't have anywhere near the power to do that. And you won't like the noise either. (Would make a vacuum cleaner sound quiet...)
Great one, thanks!!!
Man now I'm even more of a fan. Red bull all the way
sooo helpful really appreciate thank youu so much
Very interesting. Well explained, as usual. :-) I design kites and this could be an extra tool I could use. Thanks Michael!!
After reviewing this, I'll just print the nozzle and run some smoke through it at low speed.
Where did you get the smoke?
@@rmatveev yeah I've been wondering about a good source of smoke too. Most disappear fast
How I know you're an F1 fan. The team shirt, lol.
Can't wait to start buying McLaren merchandise for Danny Ric next year wooooooo Papaya and Blue baybeee!
Great Vid
Thank you so much
very cool, thank you
If you are working with newer version of Simecale than the one in the video, Instead of Using Velocity outlet use pressure outlet the same way. If you dont it will show an error and you wont be able to generate the mesh nor the Simulation Run.
New to your channel but I’ve enjoyed and learned a lot from your content I’ve seen so far. I’m looking to get into designing my own prints, but am a complete newbie. What would be a good way and program(s) to start with to get my feet wet? Or if there are specific videos you’ve already made on this, I’d love to watch them.
Keep up the good work and thanks for making these videos!
Great vid thanks! :D
5 star video.
Very thorough video! I’ve often wanted to check airflow on various parts cooling nozzle designs. Thanks for taking the time to demonstrate it. I was not familiar with this software. I’d be curious how similar or different the process would be using the Fusion 360 CFD module?
Thanks for making this, I tried this service several times and could never get it to work... just the trickiness of the UI methinks. This weekend I’ll give it another try following your guide
Ahh You are a teacher now it makes sense why you’re so good at this! I’m sorry I had to takeoff my patrion for now times are tough at the moment But I will be back once things get back to normal
The channel name probably makes sense to you now too ;^)
I'm working on trying to see how air flows through a paint booth. Hopefully the way you set it up in the beginning will help me as I had no idea how to set up the internal volume and entry points
Thank you for this video ! You give us some very good information !
I want to simulate the pressure under my resin 3D printer Saturn 2 plate. I found some mathematical model not easy to implement so it would be great to simulate it !
The idea is that the efforts under the plate of the printer are getting very very high values during the last part of the z moving down in the fluid because of resin viscosity.
The software doesn't support fine tuning of the velocities bur with the amazing UVTools it is possible to add temporisations for the first layers.
So what do you think about using Simscale for my purpose ?
Thanks again
Brill have just finished my fan ducting for my predator, might give it ago, then look at modelling the RX3 coupe racecar cheers
Hi Michae , Have been trying to re-build my ender three with a SKR1.4 turbo board and a TFT 35c screen and 2209 stepper drivers.Following you guides and using your new editor choice(visual Studio) which I like . Iseem to load Marlin 2.0 into it fine then do all the changes OK but then when it comes time to compile there is no tick in the bottom tool bar ther are no mistakes and no problems but NO TICK TO PRESS TO COMPILE THE CHANGES .Lockdown frustrations here in Nowra and not knowing the software dosn't help,can you thanks Ian
As another user said, it‘d be more useful to learn how the results actually inform my design. Simple visualization of the first iteration is nice to look at, but whether the airflow hits the nozzle or not is obvious in the most cases. But there‘s a whole process involved in optimizing airflow before the outlet. It would be nice to see how you go from a first design, to an optimized one in multiple iterations, with help of CFD.
Exactly my point too!
This is awesome, I have been looking for a CFD program. Hopefully this can pair with Fusion
Yes it does, just export your model as .step
For proper duct simulation you also need to simulate the fan as it doesn't produce laminar flow.
Well I´m not sure to know what the aim is here. Of course I can see the behavior of the air and in one case I can see there´s barely air the the endings but a simple fan duct should just blow in the right direction or not? I hope you can explain me which points are important? I´ve created a test STL with a box around it and it´s still calculating. I really would like to know more about what a critical position / area would be ... everything what would be red? ... or where I can see much less air at the end?
Hi Michael.. can you please update this Video to be used in the new version of Simscale
Now I want to see an aerodynamic simulation of an F1 car covered in fur.
If you are getting the error "A setup with 2 regions is being used in a single-region analysis type" -- you must delete all solids except for the new volume that you created like another commenter posted. It's not obvious from the error what step is missing, but that's it. TT does this and mentions it but it isn't explicitly shown on the video. Check out the video top right at 5:44 vs. 5:49 and you'll notice that all geometry except the new volume is deleted. If you're having this problem, go into CAD editor, look at the geometry, and remove (delete solid) everything except for the volume that you created. It's similar to a 'burn out' in the lost-PLA casting; the original solids must be removed. Then things should work. Also, in the new UI, you'll want to perform an internal flow-- but most everything else still works. The other difference with the new UI is that the gauge pressure is used and not absolute static pressure. I believe the new default values of "0" should be fine. Also, incompressible flow is free but compressible is not. That should be fine -- air is roughly incompressible below 230MPH (mach 0.3).
Compressible isn't free anymore. Apparently can be done with incompressible analysis but I can't seem to work it out. Do you have an updated guide?
I tried to run the simulation on my own (slightly more complicated) design and found that *Open inner region* is not that straight forward when the geometry is non-trivial and there is no message that would tell _why_ this wouldn't work.
The Start button merely blinks but doesn't do anything.
Any idea if this can simulate an air impulse? I've got some weird ideas for percussion instruments and I'm interested in testing the airflow inside the drum to see if any of my theories might work. 😄
how do i make a box around the object because when i try it just seems to delete the object?
Hi, do you know of any way to put a 3d model into a program and simulate wind on it, so it moves as if it was real wind?... I'm interested in making wind spinners and seeing how they would move in real wind...
Hi michael. Good explanation. Its very useful.
Could you do some thermal analysis to a hotend someday?
Could you do thermal+CFD to see the impact of the fan duct on the hot end?
i was looking at cfd weirdly enough and saw simscale, but figured might have been best to use openfoam within freecad.
How do they work together? The FreeCAD FEA is surprisingly easy to use though quite buggy. Overall though FreeCAD's been getting pretty good.
@@justincredible5406 haven't used it yet, but when looking for cfd's. openfoam came up as one that was integrated into freecad about a year ago i think in version 17. But seeing a few videos on it and the general reviews of openfoam make it seem good. Though does appear to have a higher learning curve.
You might want to consider using Copper-filled Metal Composite HTPLA by proto pasta. I played around with it a little bit and the resistance level is nowhere near the resistance level that you showed for the carbon fiber. Might be something to play around with sometime when you have time I certainly don’t have the time right now to do something like that. You must send this after printing of course.
What I find missing is what to actually learn from CFD or FEA. I mean you can plot stresses or airflows, but it's harder to actually inform your design. Much is obvious already before simulation.
This is not related to the video subject but is a bigtreetech skr 1.4 be connected to a makerbase mks tft35 v.1. The display has an 8pt chord but the skr board has a 10pt input. They both have an identical display tft35 yet the connection is different. Is there a way to modify a chord/chords to connect them to each other. I also have a 10pin USB programmer if that can somehow help. I would be beyond grateful to get some help on this frigging thing. Its pretty much the bane of my existence right now and there's nothing anywhere about this which I'm very surprised by. But you're pretty much the man when it comes to this stuff so figured I'd ask. Thx
phew, really had me going there for a sec! i was just about to get "triggered" over the heresy of an assymetrical fan duct ... but then you've made the world good again!
On times of Ryzens and Threadrippers, you should go for a non-cloud based program :D
That's a bit silly to do. Not many people will be able to use the full potential of a threadripper cpu and thus that's a waste of money. In this case, you're only using the resources when you need it. Also, I doubt any of the Ryzen solutions out there are powerful enough for CFD in a reasonable amount of time.
What class did you teach and was it highschool or college? When i was working on my areospace engineering degree, i taught highschool myself:) its alot of fun
can you do a updated video. i think some of the options has changed.
OK it's probably only me - but I have designed everything in Fusion360, exported it as .step; and it complains about "Sheet bodies detected.
The model contains sheet bodies (surface data) only. The meshing algorithm requires at least one solid region. Try to solidify all surface parts." - any idea how to solve/fix this?
I would like to change the original CR-10 motherboard, what do you suggest?
I've tried and tried, and it's just error after error. The fan duct is a solid body, but it continually imported into simscale as 3 faces. So ended up importing into onshape just to be able to export as a parasol. Well, that worked, but then when calculating inner region it gave the error "The flow region could not be created." which turned out to be a geometry issue which was cleaned up. But now it's saying it's too course even when I set the fineness to 10. I've spent a few hours on this and still can't get any further.
www.simscale.com/projects/phazei/lpa_fanduct_5-5/
Yeah, that shirt is great
Always enjoy your videos. Unfortunately SS no longer allows CFD for compressible flows simulation on the free version. Seems they must have noticed an uptick of people using it and decided to monetise it.
thats was the viddeo I was looking for!! but now I'm stuck at the first step... when I hit start nothing happen
Please redo this video with the new version. I cannot get the sim to work, telling me I have too many regions.
I think you need more sponsors on your shirt.
Also flow into restricted duct will not be rated flow of the fan, but much lower.
Yep, and Max pressure will be limited by the static pressure the fan can generate.
With the compressible simulation no longer being available, it should be noted that "incompressible" is the correct choice here anyway, because air is moving at slower speeds than mach 0.3. So, unless you got a really powerful fan...
Thank you!
Well Cool video, I couldn't get it to work. Kept failing open inner region despite boxing it in like yours.
It is not free many times I tried but unfortunate every time it asking a company name and number of employees so just 10 cfd simulations are allowed.
the CFD is pretty interesting. I wonder if someone has a tuto similar for FreeCAD? thanks!
freecad has openfoam, but finding good tutorials on that are hard. which sucks since it seems super interesting also like how it's free, open source, and your stuff is saved or exposed somewhere other than your own pc.