Quote:
Originally Posted by brucepick
I have this idea that the airflow won't follow a curve without having a physical shape there for it to follow. I'm guessing there's a separation point as it tries to follow the downward curve of roof + rear glass. After separating, I think it would continue in a straight path if not otherwise influenced.
So for the airflow after the roof, I drew a blue line tangental to the final roof curve, starting just before the rear glass. Then a 2nd blue line which would be a spoiler that meets that line.
Both the earlier red and black lines come close to the blue line I added. The red line meets my blue one just about perfectly; the newer black line extends through it just a bit.
What do you folks think? |
I think I don't know, but thanks very much for working with my image. One problem with my overlay is its resolution, the scale of which is not precise. Even with the image, I cannot be sure of placements, angles, lengths and such. What you say sounds plausible. I think I'll have to just improvise like a musician: get a feel for something that "works" and then try it and see.
Your comments make me think of an image MetroMPG posted on this site some time ago:
http://ecomodder.com/forum/member-ae...-kamm-back.jpg
The airflow here has begun to disperse, scatter after separating from the tail end. Maybe that demonstrates your point. My understanding is that the long flat spoiler *might* allow such flow to briefly reattach (to the spoiler) and separate from the tail of the spoiler cleanly, reducing vortices, the wake, and the drag effect of the more steep rear window. That's what I think I am doing, based on what I read here on this site. But a little knowledge is sometimes a dangerous thing... !
I scoped out a test route today on a section of freeway closer to my house. It will allow me to try 60+/- speeds at a steady 16.1 throttle for 6.2 miles each way. All I need now is a clear and still day.