Besides the other comments below, I would like to know: 1) Comparison with experimental data (otherwise I have no reference as to which one was more accurate) 2) Total computational time 3) Software cost (this one is my favorite).
adas1023 Hehe, I know it's OSS, that's why I like the comparison: a libre software performs as well as a paid one. I just want to know how on par are they.
Nacionarg It could be true about libre software performing as well as the paid software, but from personal experience, time and effort costs are certainly not the same yet, and skew towards the paid version being cheaper on sufficiently large projects.
adas1023 I know the price of fluent....as you have to buy other modules of Ansys the basic star price is over 50000 dollars. they will tell you that Ansys has customer support but their customer support sucks. They also will tell you that they help you in the first project but that is not true. Ansys times are too slow compare with the urgent times that the user require
I totally agree, when they zoom out to show the field the velocity contours are completely different. It looks like they have applied a wall condition in ansys-fluent. If the boundary conditions are not exactly the same it's hardly a valid comparison.
Some obvious conclusions: 1) contrary to OF's, ANSYS's simulation seems to have some turbulence on the inlet. 2) doesn't ANSYS fluid have lower viscosity? It displays sharper pickup of momentum (more intensive ripples...) and a higher dissipation afterwards (straight line after 150). 3) The outlet BC seems wrong in ANSYS... Do you see that green buildup at the outlet corners? Could anyone comment on that please? I'm studying and I'd really like to know the reasons behind this.
Absolutely beautiful graphics. Mindboggling number of hours must have gone into learning and preparing all that stuff!!! Has anyone attempted to compare predictions with reality, to see which of these 2 products "wins" ?
Nice, but it's lacking some important info: did you use the same mesh? What about the time advancing scheme? Is it an immersed body method, or you're using dynamic meshes? Maybe do a more standard comparison, with fixed mesh size and 3 refinement levels, so we can really see what's going on.
Good video. I have a question. There seems to be difference at the outflow (right end) boundary between the two codes. Fluent seems to have periodic BC (not sure) while OpenFOAM looks to have convective BC. Please explain.
1:45 Observe the unphysical airflow at the boundaries & outlet of wind tunnel in Ansys fluent . It is not present in Open foam. Probably it has to do with coarse mesh or type of boundary conditions applied at the wind tunnel boundaries
This is an awesome model and results presentation. Did you use exactly the same models on both codes? Why do you think there is such a noticeable diff near domain boundaries?
It can be seen that BCs are different. Also the discretization is more diffusive in the OF case. It is possible to exactly replicate the fluent results if you exactly replicate the schemes, solvers, and all other settigs
Yeah Outlet BC on Ansys definitely has a different setting, the back flow/pressure seems to explain the fast stabilizing of flow in the Ansys example. To compare it is very important the outlet conditions are the same, well made video nonetheless!
this video is interesting. what solver did you use? Is it in MRF or sliding mesh? and could you share with us how the step did you make this simulation? Best regards, Aldias
It kind of pains me to see this because I know that there's a better way and that you'd get a more powerful output But Hey if people want to do it the wrong way that's their right to make the most inefficient machine out there
Common sense tells me the closed source (Ansys) has real professional engineers directed to make a real engineering software with strict quality control. Then you have freelancers on their break time making free open shit (OpenFOAM) with no quality control. Yea for people with their stupid projects go with OpenFOAM, people with serious projects like NASA or SPACEx goes with Ansys.
Eventually Open Source will have to take precedence, because we can't afford to be permanently limited to paying someone with no alternative quality software. I don't see why quality alternatives can't exist in the public domain. Companies apparently won't be the ones to do it, and these people are only the ones who do. Why talk down on them?
@@jyothishkumar3098 I have been using software for a long time, engineering software that requires great precision and fine details of information and computation requires a lot of man power, thought and research & development. This is why in most cases the paid stuff is usually better, they have the investment to make prefect software for the right tools for the job. Over the past two decades, I have never seen open source being better than paid counterparts in engineering software. However recently in the past few years, I have seen open source being much better than paid software in multimedia sector. Hopefully the same will be true for engineering and science software. There seems to be a traction to open source engineering and science software, usually it becomes popular then simply flops dead. I like open source, nothing wrong with it, just that in some cases, the paid stuff is the way too go currently. I use FreeBSD OS, it is the best OS and it's 100% free and open source, it lost traction but slowly gaining traction again. Open Source software needs a way to get investment, nothing is free, we need a way to pay developers to make quality open source software.
Besides the other comments below, I would like to know: 1) Comparison with experimental data (otherwise I have no reference as to which one was more accurate) 2) Total computational time 3) Software cost (this one is my favorite).
Well i dont know about the first 2 questions, but openfoam is free, and opensource
adas1023 Hehe, I know it's OSS, that's why I like the comparison: a libre software performs as well as a paid one. I just want to know how on par are they.
oh right lol
Nacionarg It could be true about libre software performing as well as the paid software, but from personal experience, time and effort costs are certainly not the same yet, and skew towards the paid version being cheaper on sufficiently large projects.
adas1023 I know the price of fluent....as you have to buy other modules of Ansys the basic star price is over 50000 dollars. they will tell you that Ansys has customer support but their customer support sucks. They also will tell you that they help you in the first project but that is not true. Ansys times are too slow compare with the urgent times that the user require
looks like a difference in the outflow boundary condition
I totally agree, when they zoom out to show the field the velocity contours are completely different. It looks like they have applied a wall condition in ansys-fluent. If the boundary conditions are not exactly the same it's hardly a valid comparison.
@@Meritzio Regardless, the difference in velocity at the sample line is only about 3%
Some obvious conclusions:
1) contrary to OF's, ANSYS's simulation seems to have some turbulence on the inlet.
2) doesn't ANSYS fluid have lower viscosity? It displays sharper pickup of momentum (more intensive ripples...) and a higher dissipation afterwards (straight line after 150).
3) The outlet BC seems wrong in ANSYS... Do you see that green buildup at the outlet corners?
Could anyone comment on that please? I'm studying and I'd really like to know the reasons behind this.
You noticed to the clues very well
I learnt a lot
thank you
Absolutely beautiful graphics. Mindboggling number of hours must have gone into learning and preparing all that stuff!!! Has anyone attempted to compare predictions with reality, to see which of these 2 products "wins" ?
could you make the openfoam case public, please ?
Nice, but it's lacking some important info: did you use the same mesh? What about the time advancing scheme? Is it an immersed body method, or you're using dynamic meshes?
Maybe do a more standard comparison, with fixed mesh size and 3 refinement levels, so we can really see what's going on.
Is it jut me or is this wind turbine running in reverse (both the flow direction and the direction of rotation)?
It is just YOU... :P
Good video.
I have a question. There seems to be difference at the outflow (right end) boundary between the two codes. Fluent seems to have periodic BC (not sure) while OpenFOAM looks to have convective BC. Please explain.
Take a look at 1:39, I am pretty that is not periodic BC
1:45 Observe the unphysical airflow at the boundaries & outlet of wind tunnel in Ansys fluent . It is not present in Open foam.
Probably it has to do with coarse mesh or type of boundary conditions applied at the wind tunnel boundaries
This is an awesome model and results presentation. Did you use exactly the same models on both codes? Why do you think there is such a noticeable diff near domain boundaries?
It can be seen that BCs are different. Also the discretization is more diffusive in the OF case.
It is possible to exactly replicate the fluent results if you exactly replicate the schemes, solvers, and all other settigs
Yeah Outlet BC on Ansys definitely has a different setting, the back flow/pressure seems to explain the fast stabilizing of flow in the Ansys example.
To compare it is very important the outlet conditions are the same, well made video nonetheless!
No mention of numerical schemes, boundary conditions, experimental data, solvers. This is no comparison, this is just fancy plots
this video is interesting.
what solver did you use? Is it in MRF or sliding mesh?
and could you share with us how the step did you make this simulation?
Best regards,
Aldias
Hi, how you make this video? which software?
Ensight
I wish I could tell you how INEFFICIENT it is but by doing so I would be telling you my idea on wi. Flow dynamics
Hello, could you describe how you visualised the vorticity in Fluent in details, thanks
How you build dynamic chart?
Hello, nice videos, how do you put the graphic and the video together? Thanks.
Which is more accurate?
It kind of pains me to see this because I know that there's a better way and that you'd get a more powerful output But Hey if people want to do it the wrong way that's their right to make the most inefficient machine out there
What actually do you compare?
in which program did you do it?
how do you plot the graph in OpenFOAM velocity over time, I am using ParaView but struggling? can anyone help!
?
Whats a programme can build dynamic charts?
i think maybe u can use fieldview software
well...if this is equally in both platforms simulated then the difference is vast....!
It is funny to see the guys who came to see this video on a comparison between simulation codes then saying just "no mean without experimental data".
ye, it pisses me off :D, great job from the author
Well, exactly!!! You need to see which is better by comparing them to the experimental results. Then you know which is better.
Common sense tells me the closed source (Ansys) has real professional engineers directed to make a real engineering software with strict quality control. Then you have freelancers on their break time making free open shit (OpenFOAM) with no quality control. Yea for people with their stupid projects go with OpenFOAM, people with serious projects like NASA or SPACEx goes with Ansys.
OpenFOAM made by researchers, not freelancers.
@@deniszaika9534 Same thing, researchers doing freelance work. Jerez that was a stupid comment.
@@ShopperPlug LINUX is free. Windows is not. Google runs on LINUX.
Eventually Open Source will have to take precedence, because we can't afford to be permanently limited to paying someone with no alternative quality software. I don't see why quality alternatives can't exist in the public domain. Companies apparently won't be the ones to do it, and these people are only the ones who do. Why talk down on them?
@@jyothishkumar3098 I have been using software for a long time, engineering software that requires great precision and fine details of information and computation requires a lot of man power, thought and research & development. This is why in most cases the paid stuff is usually better, they have the investment to make prefect software for the right tools for the job. Over the past two decades, I have never seen open source being better than paid counterparts in engineering software. However recently in the past few years, I have seen open source being much better than paid software in multimedia sector. Hopefully the same will be true for engineering and science software. There seems to be a traction to open source engineering and science software, usually it becomes popular then simply flops dead. I like open source, nothing wrong with it, just that in some cases, the paid stuff is the way too go currently. I use FreeBSD OS, it is the best OS and it's 100% free and open source, it lost traction but slowly gaining traction again. Open Source software needs a way to get investment, nothing is free, we need a way to pay developers to make quality open source software.