Quote:
Originally Posted by freebeard
Have you seen this?
The high top has the lowest Cd and CdA. This suggests a slow front rise and rear truncation. |
Although not a perfect model, it provides reasonable insights. By using the flow pattern depicted in the image you provided, I constrained the Reynolds number for flow illustrator. Fortunately, the length of the Astro van and the VW are quite similar, 180" and 189" respectively, resulting in a negligible difference. For the VW, a more suitable Re value would be 1.13 to account for the slight variation in length.
Nevertheless, it is evident that there is more upwash in the proposed design than desired, as suggested by other members. While the overall height remains the same, the highest point has been moved toward the back, above the middle of the middle window, rather than toward the front, as in my initial proposal.
I'm not opposed to a pop top, and I may still incorporate that as well, depending on cost.