More drag reduction studies

[aerohead]

Originally Posted by California98Civic

I honestly don't think so:



Though perhaps a little depends on how high your vertical plexiglass plate rises from the trailing edge of the trunk lid?

james

None of those drag coefficients are correct. They're all based upon sub-critical Reynolds number.
I'm all for an unrestricted internet, but there is a place for peer-review.
Do NOT use these values for engineering purposes!!!!!!!!!!!!!!!!!!!!!!!!!!

[California98Civic]

Hahaha!

Aerohead, when I saw my profile associated with that, I thought I had been hacked. It is from 7 years ago! And i think you maybe forgot you already responded to it in this thread exactly like this, back in 2013? Here: https://ecomodder.com/forum/showthre...tml#post365364

No problem. Thx.

[Vekke]

Found this kind of study:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7153308/

[freebeard]

I don't think there is a current CFD thread so I'll drop this here:

BEST Features in Blender 3.6 in LESS than FIVE Minutes! at 2"22

I don't see a CFD solution in Blender yet; but the new Simulation Node editor creates a framework with supporting data structures (OpenVDB) to enable that. Much like creating AI prompts, the design of node trees is non-trivial.

So, 3.6 extends functionality in the node editor with something called Implicit Sharing.

Instance on Points
Instance to Points
Points to Vertices
Mesh to Points

....are all ten times faster. This is on top of loading meshes, point clouds and volumes also 10x. https://youtu.be/rRK4-k-4hRU?t=51

...these new simulation
nodes are pivotal new feature that give
artists the power to create Dynamic
simulations within geometry nodes with
the simulation input and output nodes
simulations will evolve frame by frame
creating incredibly intricate and
real-time visual effects and you keep
your workflow streamlined all the
simulation results can be baked or
cached with the new panel in the physics
tabs

Above my pay grade, but with Free and Open Source software one person's algorithm can spread to the hive mind.

[freebeard]

Originally Posted by myself

I don't see a CFD solution in Blender yet; but the new Simulation Node editor creates a framework with supporting data structures (OpenVDB) to enable that.

That was then. Today I found this: youtu.be/tgWlTesKQ4U?t=420. (t=420 )



Why i there a low-pressure area at the stagnation point? aerohead?

[freebeard]

Well, it's another day and the desired result inches closer.

Here is a simulation of gravity with little cubic raindrops. Particle and Collision Simulations in Geometry Nodes Blender 3.5 | Tutorial

The nodes build-up includes finding the reflection angle of a normal and other useful bits. The physics engine includes wind as well as gravity so It should translate from falling drops to horizontal streamers.

I should try this. Unfortunately, we're in paint drying season so I'm trying to take advantage of that.

[aerohead]

Originally Posted by freebeard

That was then. Today I found this: youtu.be/tgWlTesKQ4U?t=420. (t=420 )



Why i there a low-pressure area at the stagnation point? aerohead?

It appears that there's no depiction of centerline flow. Everything is towards the 'camera' position, so it would all be accelerating within the Prandtl surface of discontinuity, or around the actual body. In this context you wouldn't see the 'colors' associated with static pressure & velocity pressure @ infinity.