Quote:
Originally Posted by JacobLeSann
It looks like flow reattaches at the boot and separates cleanly off the top end of the trunk. I’ve posted some tuft-test photos here:
https://ecomodder.com/forum/showthre...tml#post675015
The 2022 civic coupe has a very neat rear end. It’s a very true-to-form fast back and has some sharp separation edges at the rear. My issue being that my rear end isn’t really like that at all. I can’t really get it to take that shape without a lot of modification, hence why I’m looking at raising the lid. The 2022 Civic sedan is a bit of a better model. You can see the progressive raising of the trunk’s height over the different model years.
I think I might go ahead and test out some prototype aero mods. I want to raise the lid toward the base of the windshield, and drop it down towards the car’s rear,, flowing out into a rear bonneville-wing type extension. I think that would work very well as a fastback substitute. |
Theoretically, the CIVIC's roofline will generate too radical of an adverse pressure gradient, jeopardizing the boundary layer.
There may be vorticity that is not revealed by the tufts, and what appears as a 'true' attached flow, is actually 'downwash,' a symptom of separation-induced longitudinal vortices of high drag.
If so, you lose the potential for pressure recovery, as much of the kinetic energy of the separation bubble is lost to heat.
The fastback moderates the rate that the flow can decelerate, avoiding the threshold for separation, allowing all the flow field to gently decelerate, and build back higher static pressure where the flow finally does separate, thereby injecting higher pressure into the wake, W.H. Hucho's near-singular mechanism for streamlining.