Static pressure behind a vehicle

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Caito
Caito
13
Joined: Tue Jun 16, 2009 4:30 am
Location: Switzerland

Static pressure behind a vehicle

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Hi all,


I know that usually behind a moving a vehicle there's a pressure lower than atmospheric.

Do you have any idea how much, or how to calculate? I'm looking mostly into trucks (let's say a flat back) rather than racecars.

I've found nice plots but with no absolute values.
Image

Thanks for your help!
Caito
Come back 747, we miss you!!

Greg Locock
Greg Locock
169
Joined: Fri Jun 29, 2012 11:48 pm

Re: Static pressure behind a vehicle

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In the example, the pressure is probably dark blue = ambient-.2*1/2*rho*v^2

e36jon
e36jon
43
Joined: Mon Apr 25, 2016 1:22 am
Location: California, USA

Re: Static pressure behind a vehicle

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Greetings Caito

If big truck aero is an interest area you would really dig "Aerodynamics of Road Vehicles" by Hucho. Large vehicle aero gets a bunch of coverage (buses, trains too.). And in general it is a superb text on aero, if a bit dated. (I don't know if they have revved the edition since my copy which was published in 1987.)

Here in the U.S. there has been (finally) quite a bit of movement recently on aero devices for semis, so we are seeing things like flush wheel covers, under trailer 'barge-boards', and even foldable tapered tail fairings... (All of which are covered in the book. Nothing new under the sun?)

Good luck with your project!

Jon

Caito
Caito
13
Joined: Tue Jun 16, 2009 4:30 am
Location: Switzerland

Re: Static pressure behind a vehicle

Post

Thanks for the replies!!
Come back 747, we miss you!!