@@JokoEngineeringhelp I'm curious how it hurts a content creator. Don't you have the ability to view the dislike count? I thought it was only hidden from the rest of us.
@@glabifrons Good Question. I can view dislikes, but since viewers no longer can, it's hard for viewers to tell if educational content is actually useful or not. If a video has 20,000 likes it looks pretty good, but if that same video has 100,000 dislikes now the viewer doesn't know the content doesn't meet the needs for the majority of people. Generally my videos are between 95% and 100% positive feedback, but nobody is going to know that because of this new policy. A lot of creators with good feedback will not be able to have the public reputation they worked for.
@@JokoEngineeringhelp Ah, yes, that's precisely why I hate what youtube has done with them. I guess it makes sense that it now dilutes actual educational content (which is a real shame).
Thanks for taking the challenge. It is a very interesting workflow. I think I can follow your tutorial to implement this as an exercise for my architecture students. What about to use vertical spikes at the front of the inlet face rather than different inlet faces? I mean , the same that real wind tunnels use to produce the atmospheric boundary layer profile?
@Joko Engineeringhelp I'm not sure if it could be contributing to the issues with the first attempt, but at 6:18, you said "1 meter per second", but it changed your 1 to 0.001m/s. Also: Happy New Year. :)
It's a month since this video is out and I wanted to share my comments after trying to implement the "Gradient Inlet" approach: TL;DR: It's not recommended since the residuals are won't stabilize. Use Paraview's Calculator Filter to manually calculate the pressure per verying height. A better way for applying a gradient is to use Paraview's "Calculator" Filter and just use a formula that uses the height variable (check local/national code). Since we are talking about external flow, the external wind pressure increases from the bottom of the structure to the top and varies parabolically. Formula for determining the wind pressure should look like this: P =0.613 * Kz * Kzt * Kd * V^2 * I where: Kz = Height Factor Kzt = Topographic Factor Kd = Directionality Factor V = Wind Speed (m/s) I = Importance Factor P = Pressure (Pa) As per equation above, you can see that wind pressure varies per height and is multiplied by several constants. Since FreeCAD's CFDOF Workbench does not include these factors in the inlet, it should be accounted for in the results. Which is where Paraview's Calculator Filter comes to the rescue. Hope this helps.
If you wanted to simulate the physical strains exerted on a firearm during firing how would you approach that in FreeCAD/Calculix? Love your videos and they have helped me out a lot with doing other CFD analysis on projects in the past but I am really struggling with figuring out the right way to approach this one.
@@JokoEngineeringhelp A bolt action analysis would be really interesting to me. Simulating the peak forces on (and deflection of) the locking lugs is something that I tried a few different approaches to in the past but seeing how someone with much more experience approaches the subject would be great. Your approach to simulating the forces experienced by the barrel over the course of firing would also be cool to see but the first thing interests me more. Thanks!
@@subvertedI have done some mathematical modeling of bullet forces, would you mind sending me an email in the description? I have only modeled semiautomatics, but I believe I have some helpful tools I have made for that.
hi man, can you help me I use freecad, I don't have much knowledge, I've been having a lot of difficulty correcting my 3D models, when making the modification errors appear or the model doesn't update the modifications made in the sketch, this is freecad's fault or I don't know how to use it ? thank you so much!
Public Dislikes: Only like this comment if you dislike the video.
Public dislikes. Good idea! If only RUclips had dislikes, too. 😂 P.S. Happy New Year. Hope you had a good one. 🥂
@@PrincipalAudio I did have a good new year. I agree, getting rid of dislikes hurts a lot
@@JokoEngineeringhelp I'm curious how it hurts a content creator. Don't you have the ability to view the dislike count? I thought it was only hidden from the rest of us.
@@glabifrons Good Question. I can view dislikes, but since viewers no longer can, it's hard for viewers to tell if educational content is actually useful or not. If a video has 20,000 likes it looks pretty good, but if that same video has 100,000 dislikes now the viewer doesn't know the content doesn't meet the needs for the majority of people. Generally my videos are between 95% and 100% positive feedback, but nobody is going to know that because of this new policy. A lot of creators with good feedback will not be able to have the public reputation they worked for.
@@JokoEngineeringhelp Ah, yes, that's precisely why I hate what youtube has done with them. I guess it makes sense that it now dilutes actual educational content (which is a real shame).
What a great gift for 2022; a model from Joko! Happy New Year! It would be fun to see a sub modeled for flow.
Thanks! Happy new year and I'll see if I can fit that in
Also a happy new year with many great videos again! 🎆
Very cool.
Thanks for taking the challenge. It is a very interesting workflow. I think I can follow your tutorial to implement this as an exercise for my architecture students. What about to use vertical spikes at the front of the inlet face rather than different inlet faces? I mean , the same that real wind tunnels use to produce the atmospheric boundary layer profile?
@Joko Engineeringhelp I'm not sure if it could be contributing to the issues with the first attempt, but at 6:18, you said "1 meter per second", but it changed your 1 to 0.001m/s.
Also: Happy New Year. :)
Those units walk around sometimes! Excellent catch thanks.
It's a month since this video is out and I wanted to share my comments after trying to implement the "Gradient Inlet" approach:
TL;DR: It's not recommended since the residuals are won't stabilize. Use Paraview's Calculator Filter to manually calculate the pressure per verying height.
A better way for applying a gradient is to use Paraview's "Calculator" Filter and just use a formula that uses the height variable (check local/national code). Since we are talking about external flow, the external wind pressure increases from the bottom of the structure to the top and varies parabolically.
Formula for determining the wind pressure should look like this:
P =0.613 * Kz * Kzt * Kd * V^2 * I
where:
Kz = Height Factor
Kzt = Topographic Factor
Kd = Directionality Factor
V = Wind Speed (m/s)
I = Importance Factor
P = Pressure (Pa)
As per equation above, you can see that wind pressure varies per height and is multiplied by several constants. Since FreeCAD's CFDOF Workbench does not include these factors in the inlet, it should be accounted for in the results. Which is where Paraview's Calculator Filter comes to the rescue.
Hope this helps.
Wow thank you verry good 😃😃😃 happy new year😄😄😄
Normal OpenFOAM analysis can be executed by parallel computing to do faster simulation. Can CFDOF workbench in FreeCAD do it?
Yes, stand on the solver in the tree and the default is parallel set to true with 4 parallel cores. The settings can be adjusted.
How did you pause the simulation and resume it again?
Daer Joko
Good demonstration of CFD for Buildings, Bravo , I like it very much
How to get the print results of wind pressure on the models
Some exercises at this link will explain more of that. I'm going to make a video about these resources soon. www.opensim.co.za/training.html
@@JokoEngineeringhelp
Many many thanks
If you wanted to simulate the physical strains exerted on a firearm during firing how would you approach that in FreeCAD/Calculix? Love your videos and they have helped me out a lot with doing other CFD analysis on projects in the past but I am really struggling with figuring out the right way to approach this one.
Hey LRM! Are we talking semi automatic, bolt action or something else? Any components in specific?
@@JokoEngineeringhelp A bolt action analysis would be really interesting to me.
Simulating the peak forces on (and deflection of) the locking lugs is something that I tried a few different approaches to in the past but seeing how someone with much more experience approaches the subject would be great.
Your approach to simulating the forces experienced by the barrel over the course of firing would also be cool to see but the first thing interests me more.
Thanks!
@@subvertedI have done some mathematical modeling of bullet forces, would you mind sending me an email in the description? I have only modeled semiautomatics, but I believe I have some helpful tools I have made for that.
hi man, can you help me I use freecad, I don't have much knowledge, I've been having a lot of difficulty correcting my 3D models, when making the modification errors appear or the model doesn't update the modifications made in the sketch, this is freecad's fault or I don't know how to use it ?
thank you so much!
can we just input the inlet velocity without pressure ?
I believe the program can accept those settings