Aero of teardrop on its side?
I'm considering building a velomobile and have a question about the shapes. Typically they are a 3 dimensional teardrop. I however am looking at building a 2 dimensional teardrop, so it would be aerodynamic from the top view, but essentially a rectangle from the side.
Do I lose anything by having the airflow go around the sides? The bottom would remain flat, which seems like it would be good against the ground plane. The advantage of this shape would be two fold. 1, ease of construction. I could use flat aluminum plate for each side, top, and bottom. 2. I may add a motor and solar to the flat top side. Solar can recharge power for a velomobile in a few hours. Any data on this? The templates all go the "wrong" way. |
The problem is the air isn't going to go only where you want or decide it should go.
What's going to happen is the air on the sides will travel around this really sexy curve shape, the air above and below straight across. It's going to take longer to go around (air at sides), the air on top will not be traveling at the same speed, there will be air pressure differences between each side and the top/bottom. These pressure differences will cause air to be drawn to the low pressure areas, and as it does this it will be over distance which in turn causes a swirling or vortex. The vortex is a funnel of twisting air which results in high drag once air flow further out from the body in motion contacts or interacts with it. Your design sounds like an old soap box derby car, which I'm sure at the speed it operates at does okay as the vortexes are not too large or violent. However if you want to compete with the Velomobile, you are going to end up looking like the Velomobile. I'd like to see a sketch or diagram of your design, the devil is in the details, and where your head is and it's treatment is rather important in the scheme of things. |
Probably works quite well:http://i146.photobucket.com/albums/r...pse704b267.jpg
Mochet 1933: http://i146.photobucket.com/albums/r...ps8452d6e2.jpg |
Maybe a really aerodynamic helmet would help?
This Week in CFD | Another Fine Mesh http://afinemesh.files.wordpress.com...-cd-adapco.png The S-Works+McLaren TT | RKP http://redkiteprayer.com/wp-content/...Helmet-CFD.jpg WIND TUNNEL TESTING IN TEXAS Derby Tech - January/February, 1990 by Bruce Finwall http://derby.mypalmer.com/techinfo/d...h/windtunl.htm Quote:
Quote:
SUNDAY, APRIL 02, 2006 Extreme Gravity Car! http://photos1.blogger.com/blogger/2...ity_car_05.jpg http://photos1.blogger.com/blogger/2...ity_car_10.jpg Quote:
http://www.swedespeed.com/news/uploa.../gravity05.jpg http://www.swedespeed.com/news/uploa...scaled_600.jpg |
For context, these are some old posts on the topic I and others made in another forum back in 2010.
Random Picture Thread - Page 207 - Boat Design Forums Quote:
Random Picture Thread - Page 207 - Boat Design Forums Quote:
Quote:
|
You should help him fab it up then.
|
Quote:
I'd like to see you put a skin on that thing Frank. Seriously.:) |
FWD, but no ICE.
OP wanted easy fab. That's a reasonable requirement, especially if it means a completed project vs a stillborn one. The old Mochet quads were skinned with plywood. |
2-D 'Template'
Here is a symmetrical wing section of minimum drag (center section).Any 'shorter' or 'longer' and drag goes up.
If anything,you'd go longer. http://i1271.photobucket.com/albums/...rohead2/-2.jpg |
Quote:
Endless-sphere.com • View topic - Aerodynamics http://recumbents.com/wisil/e-bent/e...bent_fair8.jpg It would help to know if the original poster already has a Velomobile trike frame already fabricated up. If not then the yellow recumbent above may be an option. I found the comments below from the same page as the yellow one to be quite interesting. Endless-sphere.com • View topic - Aerodynamics Quote:
Fireplace acoustic absorber for enhancement of the center stage http://i184.photobucket.com/albums/x...ps1b94efad.jpg I've considered building a small one person fishing pontoon boat using the same form and techniques (+ covered in fiberglass cloth & resin). I might build a scale test model this summer to test the waters.;) NOTE: Fan-Fold insulation is much thinner and lighter than what I used above (as used on my hovercraft). However even in the thickness shown above, scoring of the insulation was not necessary to bend or arc it. In addition, be weary of the weight of glues and fasteners. |
All times are GMT -4. The time now is 05:54 AM. |
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com