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Originally Posted by Dieselguru
Seeing how this is my first post, I'll try not to overstep my welcome.
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No worries - if you've got something intelligent to say - it doesn't matter your post count... I, for one, am mildly embarassed of my post count.
Quote:
Originally Posted by Dieselguru
Tre - It would be very interesting to see some of the runs you have done at a little higher speed, say 75 mph (the speed I drive my 110 mile round trip to work every day).
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In time.... I'm a bit hard headed to thnk I would get work done while visiting family
That, on top of my analness for doing things right have ensured slow progress....
Quote:
Originally Posted by Dieselguru
If there are gains to be had, they they will show up faster at those speeds. Especially things like VG's.
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While true, gains at the lower speed should be apparent. Just not of the same magnitude... As of yet, I have not found a spot that helps (so ramping up velocity just increases magnitude of losses). Mind you, I'm working in 2D (for lack of a suitable 3D model) and flow interactions over the rear of a car are dependent on 3D interactions ("spillage" from the sides of the car). Have I seen gains with VG's in my CFD? No. Am I giving up? No, It's just not priority at the moment.
Quote:
Originally Posted by Dieselguru
As a side note: probably the reason most people don't see much improvement using VG's is that
1. VG effectiveness increases with speed (need a seperation point, otherwise its just drag)
2. VG placement probably depends very closely on speed (location of seperation point)
Look very closely at the Mitsu report on VG's. In the test setup section (page 2), they mention the baseline speed of 50 m/s (111 mph). if tre's settup is correct, will the seperation point move forward with increasing velocity to somewhat match that of the Lancer (wont be exactly the same, but simular), and will the VG's will become more effective?
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1. I tend to agree
2. Not so sure - these things aren't intuitive, so I can't say in any which direction.
Quote:
Originally Posted by Dieselguru
Tre - if you still taking requests, through higher speeds into the mix and see what happens to some of your results.
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At some point, it's coming
If I do it, I'll probably introduce more turbulent flow - because laminar flow is not representative of the low a car sees
I see aerohead made a post... I haven't read it yet, but you totally should. Aerohead has a wealth of knowledge that isn't really based on intuition (a very good thing)