Quote:
Originally Posted by mjboks
I have been wanted to get an aero cap for my truck for a while now. I used the ecomodder tool to get an idea of what it should look like.
Attachment 33576
.Here's the proof of concept from xps foam, glue and paint. I hope to use what I learned from this versions and build a better one:
Attachment 33577
Tuft test looks pretty good for a first crack.
Tuft test Video:
https://photos.app.goo.gl/Pp9tYJTwWnyYEpcbA
Hope to get A-B-A testing on version 2 as the weather warms up in Michigan. |
Flow looks good!
It does indicate the formation of attached longitudinal vortices, along the roof / sail panel intersection of the cap, which carry relatively high drag.
A solution would be either chamfering, or softening with a radius matching that of the cab.
Radius is best, but also the most intensive, as far as fabrication goes.
-------------------------------------------------------------------------------------
Also, you're creating a 'fastback' roofline, which is the most sensitive of all roof designs to tumblehome.
If you stand at the back of a HONDA Fit, looking forwards, you'll notice that the A-pillar, B-pillar, and C-pillar are all at different tumblehome inclinations.
The airflow really 'likes' this.
Again, these subtle features are the 'most expensive' to fabricate.