what is the Cd of my trike?

[Cd]

Your car is much like the Ale' - both are even Honda powered.
I think the flanks on the Ale' might give some inspiration :

[Cd]

BTW, I like your version much better.

[drmiller100]

thanks Cd - I did look long and hard at the Ale, and it has some great features.

I chose to have doors and windows which roll up and down so some things obviously are different.

I'll get some more pics today.

[NeilBlanchard]

Somehow I missed the similarities with the FVT eVaro (formerly know as the Alé). It has a hinged canopy that has a "fat" portion:




Another X-Prize vehicle that is even closer to the the layout of your trike is the Zap Alias:

[kach22i]

The "Zap" is an excellent compariable.

I think the following can also be lumped in there with Doug Miller's design. If we can find the Cd's of these cars, maybe we can make an educated guess about Doug's Cd.

Razor...........lots of turbulence coming off those front wheels.
Razor at stoneleigh...


I know this has four wheels, and is open on the sides and top, but mass wise it's in the same ballpark, and lot of drag coming off those wheel flares.
Kit Cars [group] most recent on FlickeFlu


Drag off the front wheels seems to be a part of most traditional 3-wheel trikes.

EDIT: According to this the Edision-2 had a coefficient of drag of 0.16

X Prize Winners Look Weird ... With Good Reason | Autopia | Wired.com

I read elsewhere, that the Zap World car made the top five finalist. So how bad could their aerodynamics possibly be? An exposed rear wheel, and drag inducing front wheel farings not too dissimilar to Doug's, I'd say he might be better off than we first thought.

[some_other_dave]

I'm thinking the Cd would be on the order of 0.4. But the small frontal area will make up for quite a bit.

No specific reasons, but I see lots of places for vortexes to form and for flow to be disrupted.

I would think that overall drag would be quite good, but more because frontal area is very low than because of a low Cd.

-soD

[ecomodded]

I'm taking the other side of the fence with the Cd values, The only thing in the wind is the front end. The middle and rear end are traveling behind a wind block, the amount of drag induced by that end will be next to non existent,it takes advantage of the otherwise wasteful large wake.

My car has a 0.38 Cd so my guesstimate is it has to be more then 1/3 less drag then my beetle, more like 1/2 so the Cd is about 19.

[Cd]

I'm going to guess that the Cd will be between .10 - .50 .

[Cd]

All joking aside, I don't think we have enough data to make an educated guess.
I agree that there is most certainly going to be major turbulence just behind the front fender.

Is this a running vehicle capable of doing a tuft test ?

[Sven7]

Hood.



As far as the low pressure zone is concerned, have you considered doing a "soft" body panel that would flex as you open the door and stay taut when it's closed? The BMW GINA used this to great effect, if you're not familiar.



Yours wouldn't have to be as complicated as that but I could see using a few strategic structural lines covered in some sort of treated canvas (like old airplanes) to create a "good-enough" body surface that anchors on the Civic door. This would do what Skyking was talking about, but would not interfere with ingress/egress.

Now, it's not going to be a quick project, but I think if you gave it some time and played around a little it could be pretty cool, and work well too.

Please don't reply to this with a sarcastic remark or personal attack. I'm just trying to help. Thanks.