From real world to freecad

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lhf
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From real world to freecad

Post by lhf »

i am working on old Moto-Guzzis and would like to show some pictures of the cylinder head.
Kipphebelbock2.png
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Kipphebelbock4.png
Kipphebelbock4.png (810.52 KiB) Viewed 3051 times
some parts are becoming rare, maybe we will have to produce some of these in the future.

I am using the latest Appimages of freecad. My mostly used workbenches are Part, PartDesign and A2Plus. First i need a lot of planes for each feature, i avoid using edges and faces of previous features, so everything is nearly indipendent. The head is very complex and needs almost 4 minutes to regenerate (refresh). So i think about making a compound or solid or even export to step and import to get rid of the complex history before starting the cosmetic features like fillets and chamfers.

LHF
un1corn
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Re: From real world to freecad

Post by un1corn »

Nicely done.
lhf
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Re: From real world to freecad

Post by lhf »

FreeCad is so useful in all phases of the design process. From designing to FEM-analysis, Assembly or even flow-analysis.
Here are two different inlet ports.
Kopf_Cut_Race.png
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Kopf_Cut_Race2.png
Kopf_Cut_Race2.png (550.85 KiB) Viewed 2367 times
LHF
user1234
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Re: From real world to freecad

Post by user1234 »

lhf wrote: Fri Nov 26, 2021 5:12 pm The head is very complex and needs almost 4 minutes to regenerate (refresh).
Nice. Just said, that if you set the tessellation of the model rougher, FreeCAD works much faster. The tessellation of the model takes many computation resources, and i am sure, on your model the absolutely most.

Greetings
user1234
herbk
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Re: From real world to freecad

Post by herbk »

Hi,
lhf wrote: Sat Dec 04, 2021 11:13 pm FreeCad is so useful in all phases of the design process. From designing to FEM-analysis, Assembly or even flow-analysis.
Here are two different inlet ports.
A few questions:
How did you realize the inlet flow? Just by an given inlet speed or by low presure data inside the engine?
Dos the engine have a piston to or (is the cylinder closed at bottom)? To me it looks like it's open...

A few streamlines are at an are inside the metall of the engine, especialy at pic 2. Why?
Gruß Herbert
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r.tec
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Re: From real world to freecad

Post by r.tec »

herbk wrote: Fri Dec 10, 2021 9:48 am A few streamlines are at an are inside the metall of the engine, especialy at pic 2. Why?
Hello,
I made a similar test a few months ago. The streamlines only seem to be outside. One has to cut at an angle to show the inside.
Kind regards
Helmut

https://forum.freecadweb.org/viewtopic. ... 91#p472091
herbk
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Re: From real world to freecad

Post by herbk »

Hi Helmut,
r.tec wrote: Fri Dec 10, 2021 12:51 pm I made a similar test a few months ago. The streamlines only seem to be outside. One has to cut at an angle to show the inside.
Yes of course... I should have look more closely at it... :oops: :)

But still i guess, the flow is simulated without a piston, - a engine don't have a outlet at this place... ;) ;)
Gruß Herbert
lhf
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Re: From real world to freecad

Post by lhf »

Hi Helmut,
yes, the pictures are screenshots from Paraview which is very special to use. I am nor very familiar with it.
The simulation is simply a flow-rate at the inlet and low pressure in lower outlet of the cylinder. There is no piston movement in this model. I just wanted to see the influence of different rounds in the valves area.

LHF
thschrader
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Re: From real world to freecad

Post by thschrader »

Amazing work, well done.

Rare parts:
How will you produce these parts? Metal-printer? CNC?

====================================
EDIT
CFD:
Which solver did you use?
On your sreenshot there is maxU=400 m/s ==> > Mach 1 ==> Hisa-solver
No, it is not. My eyes are getting old...
old_eyes.JPG
old_eyes.JPG (14.82 KiB) Viewed 1451 times
=======================================


FreeCAD:
For complex work I use multiple FC-files, exporting some parts as step and merge them into 1 model.
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r.tec
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Re: From real world to freecad

Post by r.tec »

herbk wrote: Fri Dec 10, 2021 8:23 pm But still i guess, the flow is simulated without a piston, - a engine don't have a outlet at this place... ;) ;)
Hello Herb,
when one is interested in the flow in the inlet channel and the flow around the valve you do not need a piston. It is more like a flow test bench where only the cylinder head is tested usually with a pressure drop of 28 inches H2O (6968 Pa) or 10" Hg (33864 Pa). The result is a mass or volume flow of air (sometimes wetted, because in a real engine the air might be dispersed with droplets of fuel on indirect injection) on different valve openings.

see: https://superflow.com/products/flowbenches/

Regards,
Helmut
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