Old School Aerodynamics

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internetscooter
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Old School Aerodynamics

Post by internetscooter » Sat Apr 06, 2013 3:57 pm

Paul
---
DLRA #647
89.664 mph (aiming for 100mph+)
Vespa Labs [url]http://www.vespalabs.org[/url]

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RGV
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Re: Old School Aerodynamics

Post by RGV » Sat Apr 06, 2013 4:56 pm

Hey Paul, yep interesting outcome. Ive been using a few of his theories on my bike. ;)

Dave

Last Minute Racing "its a 2-stroke ya twit - Its supposed to smoke"
DLRA #928
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2010 MPS/G 250 118 MPH:)
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tiggerwood
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Re: Old School Aerodynamics

Post by tiggerwood » Fri Apr 26, 2013 8:39 pm

These are very interesting tutorials. I have also used some of the techniques given here on my new bike and it worked wonders.

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internetscooter
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Re: Old School Aerodynamics

Post by internetscooter » Sat Apr 27, 2013 10:17 am

yes - there are new school lectures about but they assume you know the contents of an engineering degree to start with (lots of maths). It's good just to see it work. However note that scale models don't behave the same as the full size thing. I think the smaller you scale the model the higher you have to scale the speed to make it closer to reality.

I am currently trying to generate a teardrop shape automatically for my computer simulations. The idea is to start off with the perfect shape, then cut into it to suit the class (e.g. rider visible, nothing past rear tyre line, etc), then see how I can merge that and the original Vespa shape.

It will be interesting to see how the step through design impacts things i.e. big gap in the middle Vs no gap.
Paul
---
DLRA #647
89.664 mph (aiming for 100mph+)
Vespa Labs [url]http://www.vespalabs.org[/url]

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JonB
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Re: Old School Aerodynamics

Post by JonB » Sat Apr 27, 2013 2:55 pm

To get meaningful results with a model you need to get the same Reynolds number, faster airstream or higher viscosity fluid.

Hoerner's book "Fluid Dynamic Drag" has good info about openings in streamlined bodies.

jon
DLRA#1115
Underhouse Engineering

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internetscooter
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Re: Old School Aerodynamics

Post by internetscooter » Sun Apr 28, 2013 6:34 pm

JonB wrote:To get meaningful results with a model you need to get the same Reynolds number, faster airstream or higher viscosity fluid.

Hoerner's book "Fluid Dynamic Drag" has good info about openings in streamlined bodies.

jon
Thanks - I can get that book in the Monash Uni library - but a review of it on Amazon pointed me towards...

Image
Aerodynamics of Road Vehicles: From Fluid Mechanics to Vehicle Engineering ([Proceedings] / SAE)"
Hucho, Wolf-Heinrich


The latest book is not in the library though but I could get at the previous incarnation of the book (a earlier state of research) through my Uni account and it was a very interesting read. Basically it highlighted the difference between aircraft aero and land vehicle aero.

Here's the contents of the full blown book and I have ordered it because it is pretty relevant :)

http://www.sae.org/images/books/toc_pdfs/R177.pdf
Paul
---
DLRA #647
89.664 mph (aiming for 100mph+)
Vespa Labs [url]http://www.vespalabs.org[/url]

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internetscooter
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Re: Old School Aerodynamics

Post by internetscooter » Wed May 15, 2013 4:01 pm

The book arrived today - 918 pages! I have only got thought the first 20 pages but so far it is very good and well worth the money.

There is also a good section on motorbikes (about 40 pages). I know the DLRA rules allow an aerodynamic "hump" on leathers - I am wondering if other sorts of suit aerodynamics are allowed ;)

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Paul
---
DLRA #647
89.664 mph (aiming for 100mph+)
Vespa Labs [url]http://www.vespalabs.org[/url]

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AuotonomousRX
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Re: Old School Aerodynamics

Post by AuotonomousRX » Thu May 16, 2013 9:27 am

I reckon someone has to put in a proposal to allow Head and Bum cones

Pete
Metric Target 250 on a 250 on a Red Bike

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momec3
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Re: Old School Aerodynamics

Post by momec3 » Thu May 16, 2013 11:42 am

I understand there are already a few cone heads that have snuck through scrut...... :lol:
Chris

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