Fact or Fiction: Dimpled Underbody helps reduction in drag
Fact or Fiction: Dimpled Underbody helps reduction in drag
(OP)
i'm sure you've seen the Lexus commerical claiming that a dimpled underbody reduces overall drag on the car, is it true? and how does it do it?
would vortex generators achieve the same benefit?
would vortex generators achieve the same benefit?





RE: Fact or Fiction: Dimpled Underbody helps reduction in drag
BMW use dimples on their mirrors, so the dimples may work at automotive Reynolds numbers.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Fact or Fiction: Dimpled Underbody helps reduction in drag
Works on a golf ball!
RE: Fact or Fiction: Dimpled Underbody helps reduction in drag
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Fact or Fiction: Dimpled Underbody helps reduction in drag
I was lead to believe BMW originally used the dimples to help reduce wind noise generated by air passing between the mirror body and the A pillar.
RE: Fact or Fiction: Dimpled Underbody helps reduction in drag
The point, don't necessarily believe everything that Toyota advertises.
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Fact or Fiction: Dimpled Underbody helps reduction in drag
RE: Fact or Fiction: Dimpled Underbody helps reduction in drag
RE: Fact or Fiction: Dimpled Underbody helps reduction in drag
Regarding the question.. unless there is airflow seperation downstream we're looking to minimize, dimples and vortex generators create a lot of unnecessary drag. Compare a flat smooth panel under the car, and one with 80 vortex generators sticking out... may help in certain instances, but unless properly engineered, it will likely be a negative. We're trying to create low pressure under the car, and the extra turbulence may not help too much if you know what I mean.
Regarding the golf ball... let's model vortex generators on a golf ball and compare it to a dimpled golf ball!