Snow mods: We have been bested by mother nature.

[Frank Lee]

I know how much you guys love snerodynamics...

[Cd]

snerodynamics

Frank you are full of it today

[user removed]

No wonder the Finns are such great ice racers!!!!

regards
Mech

[Frank Lee]

Originally Posted by Cd

snerodynamics

Frank you are full of it today

Just today?

[Otto]

Originally Posted by Frank Lee

I know how much you guys love snerodynamics...

This is exactly why I asked in another thread about optimum nose shape.

Mother Nature tells us with her snowscapes that nose shapes count. It would be wonderful if somebody could extract coordinates for these shapes.

Also, for shape modification around windshield wipers, mirror stalks, door handles, etc., you could use Great Stuff expanding foam to pretty much duplicate the snow sculpture. Protect the car surfaces with Saran Wrap, slather on Great Stuff, and squeege and/or sand the foam to match the snow shape. Test.

If you build, say, a 1/4 scale model and had powder snow available, you could mount the model on a turntable with a weathervane tail, set it outside in a snowstorm, and study the results. The turntable/weathervane would keep the model facing into the wind.

BTW, in the pics above, the snow profile shape is quite similar to the leading edge of an airfoil, and also quite similar to Hucho's (page 158) "ideal" nose shape. I'd just like to see how such a nose would look in planform, i.e., from above.

[Fat Charlie]

Just keep in mind that those nose modifications are the optimal mods for those OE nose shapes, and the Kammbacks are the optimal what sticks and doesn't get blown away shapes for those bodies- not necessarily what's required to maintain attached airflow.

Beautiful shots, though.

[freebeard]

Frank Lee -- Thanks for bumping the thread. The Jalopnik article and Vekke's video are informative.

I woke up yesterday morning to what would have been perfect snow. It came down so gently it drifted half-way back into the carport. Halfway on the roof of the car, not the floor.

[Otto]

Originally Posted by Vekke

I did today some snow testing with powder snow and got pretty good results:

Testing will continue tomorrow morning because it will propably as much next night, already 3 cm .

Vekke, first of all, thanks very much for all the research and development that you do, and for sharing with the rest of us.

Questions: How far and fast to drive with snow on the car to get best shape? In other words, if you drive too far, all the snow will be blown off, with less than optimum shape. Drive too short a distance, and not enough snow will be blown off, with less than optimum shape. So, how far and fast is just right?

And, have you considered measuring depth and coordinates of the snow shapes? For example, the roof has the deepest snow about 1/3 back from the windshield, then tapers to the rear and sides. Perhaps a grid could be made, recording the snow depth at various coordinates. Laser scan?

Maybe when you come back from a drive, spray the snow with a mist of cold water, to form a solid crust on the shape. Then make impressions. From the impressions make foam copies of the snow shape, and glue on to your Lupo. (?)

[aerohead]

Originally Posted by Otto

This is exactly why I asked in another thread about optimum nose shape.

Mother Nature tells us with her snowscapes that nose shapes count. It would be wonderful if somebody could extract coordinates for these shapes.

Also, for shape modification around windshield wipers, mirror stalks, door handles, etc., you could use Great Stuff expanding foam to pretty much duplicate the snow sculpture. Protect the car surfaces with Saran Wrap, slather on Great Stuff, and squeege and/or sand the foam to match the snow shape. Test.

If you build, say, a 1/4 scale model and had powder snow available, you could mount the model on a turntable with a weathervane tail, set it outside in a snowstorm, and study the results. The turntable/weathervane would keep the model facing into the wind.

BTW, in the pics above, the snow profile shape is quite similar to the leading edge of an airfoil, and also quite similar to Hucho's (page 158) "ideal" nose shape. I'd just like to see how such a nose would look in planform, i.e., from above.

If you have Hucho's book,there should be plan views in the 'trailer' section,there should be one for Moller's VW microbus, VW's LT (Vanagon),and back in the commercial vehicle section for buses and 18-wheelers.
It's just a matter of leading edge radii along with side camber.
The caveat is the 'bulbous' (or 'Bug' as Koenig-Fachsenfeld referred to them) nose investigated by Hans G'o'tz,which has the all-around lowest drag when crosswind is factored in.
These date to 1911,with Oscar Bergman's airship car,which predated Count Marco Ricotti's Alfa Romeo 'trompe le vent.'
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"There is no magic radius.I think you have to stay away from an obvious hard edge,and then there is quite a bit of freedom as to how much you soften it,depending on what you want it to look like and how much you can curve it without interfering with mechanical components."
David Holls,Director,Advanced Design,General Motors Corp.,1982.
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"Once you've got a clean front end,well over half the problem is how you handle the rear of the car." Chuck Torner,Director,Advanced Engineering,General Motors Corp.,1982.
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" the shape of a body in front of the largest cross-section has only minor influence on the total drag.The main contributions for the drag force originate from the rear part of the body." Wolf Heinrich Hucho,Director,wind tunnel operations,Volkswagen AG

[freebeard]

"Once you've got a clean front end,well over half the problem is how you handle the rear of the car." Chuck Torner,Director,Advanced Engineering,General Motors Corp.,1982.
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" the shape of a body in front of the largest cross-section has only minor influence on the total drag.The main contributions for the drag force originate from the rear part of the body." Wolf Heinrich Hucho,Director,wind tunnel operations,Volkswagen AG

They agree on the rear, but [may] disagree on the front [, it's ambiguous].