Aerodynamic mods and their effects, and dimples!

[Cycle]

This PDF file tracks what changes were made and the effect upon CD:
http://www2.warwick.ac.uk/fac/sci/wm...tion120221.pdf

This one examines drag reduction by surface dimples:
http://waset.org/publications/100008...urface-dimples

(Note: if you can't get the second PDF file to open in Chrome, it'll open in IE)

[freebeard]

The first PDF appears to be a newer version of the Coventry University slides. There are changes from the version I'd seen, like a new example in the box cavity section.

It would be interesting to hear the lecture[s] they support.

[Vman455]

The dimple study has dubious application to real-world cars, I think. Their analysis only shows what we already know: where airflow is detaching from an object, adding a dimple (or a vortex generator) will delay flow separation by adding energy to the airflow. The problem here is, the authors did not investigate the effect of multiple dimples on the shape of an actual car, just one dimple on a small part of a very simple body.

[Cycle]

I find it interesting that they say annular rings around the wheels can be more effective than pizza-pan discs.

[aerohead]

Originally Posted by Cycle

This PDF file tracks what changes were made and the effect upon CD:
http://www2.warwick.ac.uk/fac/sci/wm...tion120221.pdf

This one examines drag reduction by surface dimples:
http://waset.org/publications/100008...urface-dimples

(Note: if you can't get the second PDF file to open in Chrome, it'll open in IE)

The investigators apparently weren't aware that better vortex generators exist than dimples.

[aerohead]

Originally Posted by Cycle

I find it interesting that they say annular rings around the wheels can be more effective than pizza-pan discs.

It looks like the investigators tested flat discs,rather than pizza pans which protrude away from the wheel a bit,or MOON-type covers which are convex.
For 100% coverage,the flat disc appears to outperform the annular rings.