Solidworks CFD simulations

[Vekke]

I have a Solidworks Flow licence in test use for 15 days.

If you have any basic shapes and ideas you would like to test in 2d or 3d make some rough sketch what is the situation and why you would like to know what is happening.

First I will test some tire shapes and deflectors infront and behind the tires.

In my calculations the wind speed is set to 100km/h or 27,77m/s. Some calculations have ground effect taken into account, but specially the first ones its not taken into account.

[aerohead]

1) I'm willing to face complete humiliation in front of the entire global community, if you investigate the aerodynamic streamlining template, Generation-III.
2) I have super-critical Reynolds number empirical wind tunnel test data for it from the DARKO Wind Tunnel for comparison quanta.
3) Wolf Heinrich Hucho has presented data for other 'basic bodies', dating to 1922.
4) Rolf Buchheim et al's 1981 testing results at the Volkswagen AG, climatic wind tunnel, for basic bodies tested by PhD candidate, Wolfgang Klemperer, in 1922, at the Zeppelin Werke happen to be exactly the same Cds.
5) In, SAE Paper 2020-01-0673, PhD Jeff Howell et al, mentioned that, as of 2020, 'it is remarkable , however, how little data is available on the effects of streamlined tails on non-axisymmetric bodies, whether representative of road vehicles or not.'
6) This would be an opportunity to add to the body of knowledge.
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7) As of 2017, I posted a 4-view- representation of the scale-model tested in Utah.
Thanks for considering it. I'm sure that certain parties would love to experience schadenfruede if the numbers didn't stand up.

[Vekke]

Where can you find the template number III?

[aerohead]

Let's try this. If it doesn't work I'll go for help, or put a copy of the 'blueprint' in the mail to you.https://ecomodder.com/forum/showthre...-32673-13.html
The image is the sixth photo down, at # 125 (permalink)

[freebeard]

Apologies for not having a single graphic:




Octahedral geodesic geometry. I could DM an .OBJ or tell you how to generate variations at will*. The octahedon-based geometry provides four-fold symmetry on the X, Y and Z axes. This allows variation of fineness ratio, max camber, truncations and lowering the 'equator'.

I'm also curious about the Cd curve from planar octahedron to quasi-spheroid (changing frequency).

also


*(docs.blender.org/manual/en/latest/addons/add_mesh/geodesic_domes) There're capabilities there that I hadn't realized. The last picture I modeled in Wings 3d. The add-on has Square and Rotate Square parameters that would allow this to be animated.

[Vekke]

Got it I will make it 4meters long from front to back or you have better idea?. that picture seemed to be level. Will do same construction to template 1 and 2 also.

[aerohead]

Originally Posted by Vekke

Got it I will make it 4meters long from front to back or you have better idea?. that picture seemed to be level. Will do same construction to template 1 and 2 also.

Whatever is 'easy' for you.
We just need the CFD to run at a super-critical Reynolds for the length.
If the 'Template' had an overall height of 1409.7mm, like many current cars, it's length would be 5394.8mm overall, 'long' by conventional standards, however, much shorter than some heavy-duty pickup trucks sold in the USA.
Also, the rear third of the car could be an 'extensible' elongation, as envisioned by the Germans in the mid 1930s.
Again, thanks for the consideration.

[Phase]

Definitely interested in deflectors in front of the wheels of cars. Actually chipped off one of my rear wheel under body deflectors and was going to fab up a newer and possibly better one this summer?

[Vekke]

At the moment clearly best drag came from AST II template 0,104

AST I Cd 0,114
AST II Cd 0,104
AST III Cd 0,113

Test 3d model is 500mm wide and all edges is rounded to 100mm

Cd values are not exact, but they are just comparable between each other the runs above. I ran the simulation at full resolution for 35 iterations. I am still learning so will get back to these results in the weekend. Migth be just that the mesh is still too small for the curvature.

The rear diffuser angle is same 11 degrees in all as AST III. Which is too steep IMO, on the AST II and AST I its 10 degrees. Ground clearance is also quite low like 82mm. Now its same on all is that ok or do I raise it to 140mm range or some other value?

I did run first tests with AST III model that was sitting at 100mm Then I got Cd 0,111 with 35 iterations so lowering helps... I also did one run to 130 iterations with that model that was 0,108 so drag values will get lower if you run it longer. Full run with that accuracy is over 6 hours of running. So I will put the machine running on nigth for final results for certain models.

Pictures of my simulations will come here
https://www.facebook.com/media/set/?...62635480416932

[Vekke]

Did full run on the night to AST III and it only gave 0,110 with finer mesh and full run.




So at the moment I believe Template AST II is better. Next I will test the EQXX roofline shape against the AST II cutted to same length.