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Okay, I'm sure I will get bashed for this, but has anyone done any aerodynamic testing with a whaletail on the original Insight? For asthetic reasons and because I park in the sun, I want to mount a solar panel on the back, and would like to integrate it with a rear spoiler.

I'm thinking if I find the angle the air is currently moving, maybe there won't be too much drag from it.

What do you think? Also, asthetically I think our little cars look pretty good, except for the "petticoat" look of the rear bumper, and I think a whale tail might balance that out.

Thoughts?
 

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Okay, I'm sure I will get bashed for this, but has anyone done any aerodynamic testing with a whaletail on the original Insight? For asthetic reasons and because I park in the sun, I want to mount a solar panel on the back, and would like to integrate it with a rear spoiler.

I'm thinking if I find the angle the air is currently moving, maybe there won't be too much drag from it.

What do you think? Also, asthetically I think our little cars look pretty good, except for the "petticoat" look of the rear bumper, and I think a whale tail might balance that out.

Thoughts?
Cool idea. My hunch is the small lip at the edge of the kammback tail gives the aerodynamic effect of a whale tail but, why not give it a whirl?
 

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A whaletail? Like on my old 911? Honestly? My thoughts... or rather, thought...

:rotflmao:

Now that I've got that out of my system... go right ahead... :rolleyes:
 

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somewhere on the web, there is a photo of an insight with a whale tail. It looks like a photoshop job. If I run across it again, I'll add the link. If someone else wants to search, have at it.
 

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Discussion Starter #5
Ok ok

Not really a "911 style" Whaletail, a rear spolier, rear wing, etc, not hip to the proper lingo I guess....

similar to, but larger and broader than this....

Still laughing?
 

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Ok ok
Not really a "911 style" Whaletail, a rear spolier, rear wing, etc, not hip to the proper lingo I guess....

similar to, but larger and broader than this....

Still laughing?
Ah. I see. OK, I'm down to chuckling now. ;)

I was envisioning this:



The Insight is such an aerodynamic marvel that any appendage would probably be detrimental to its Cd... wouldn't mounting it more flush with the roof work better? Just saying... :D
 

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Why are you creating downforce on a front wheel drive car? What I thought was a neat idea was creating up force like increase the airflow under the car to make it seem lighter then it actually is, and thus making better gas mileage. Also on the flip side creating too much upforce will flip you car over if you take aggresive turns...

Just realize why you are creating it. The Insight has the best Coefficient drag that any other car on the maket has or had...

Harvir
 

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Discussion Starter #9
Thanks for the response Harvir. I was mostly thinking of doing it for asthetic reasons, but I have decided just to live with the way the car looks. Creating up force at the back would not give you better mileage at all, nor would it change the mass of the car and make it seem lighter. At an extreme all it would do is unweight the back wheels at high speed making the car extremely dangerous to drive at high speed.
 

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There is substantial room for aerodynamic improvement in the Insight. The AeroCivic achieved a Cd of 0.17 by streamlining a Cd=0.34 '92 Civic hatchback. I believe it will be possible to achieve the same or better shape (Cd=0.17, 32% reduction in highway fuel consumption, plus extending lean burn) with an Insight with less effort and shorter overall length, and I intend to do so. Here's a rough sketch of what I have in mind. It's 95cm longer than stock, which makes the car as long as an Accord.



The rear truncation is as tall as a US license plate, and leaves room for a few lamps on either side.

When a 16" tail cone was fitted to the GM EV1, the drag coefficient dropped from 0.167 to 0.153. (source)

Btw, is anyone here good with OpenFOAM?
 

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RobertSmalls, This is interesting. I'm not an expert on aero, but I thought having a sharp edge on the back is supposed to break the air connection from the car rather than creating a suction region such as having a tail on the car. I'm interested in your results, hope this works out. :)
 

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Agreed very interesting and look forward to the results. Have to be careful with the overhang over here need to look at the regs for protruding load lengths.

I've been looking at the front of the car and the two air intakes which I would like to block with a professional looking removable nose cone/inserts similiar to what you have at the rear.

Again I need an expert in foam/fiberglass to knock something up that looks stock and possibly get some moulds made to churn them out!
 

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I Love the work you doing by the way. Also which program are you using to build and test your your "car"? I also mean to create down force in the center of the car. Usually sport cars designers try to get all the weight of the car in center so it can corner better.

Harvir
 

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Thanks for your interest. It's actually a collaborative design effort, and I'm optimistic about the potential for aerodynamic improvement.

@MN: an abrupt end to a car, or sometimes vortex generators, do a better job reducing the size of the high drag vortical wake region than rounded edges. However, filling the region in with something solid does a much better job of reducing drag.

@Harvir: It looks like I'm using Pro/E and ANSYS. The local university uses ANSYS for CFD, and despite its refined GUI, it's a very complex program that I'm presently unable to get results from.

For the 3D model, I traced drawings from the InsightCentral encyclopedia as a basis for a crude 3D model, then added a tail based on the streamlining template you see in the rendering I posted.

Next step: wait for spring and begin fabrication.
 

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I think a decent halfway house could be making the rounded corners cut sharply (more like the Gen3 prius) and doing something with the rear difusser more like a Gen2 prius with more flat floor.

The Merc E class in base form will have a Cd of 0.24 thanks to extensive underfloor work.
 

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Thanks for your interest. It's actually a collaborative design effort, and I'm optimistic about the potential for aerodynamic improvement.
That's a very interesting thread. Excellent.

Should I win the lottery anytime soon you will be high on my list for funding with some serious gaffer tape, cardboard and windtunnel time!
 

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Robert,
That's about the shape I was thinking about.
Some additional ideas.
Make it hollow so it can be used to stow things?
Add a steerable wing for tuneable down force?
Tail light optically coupled repeaters.
Easy to remove.
Built in Solar panel.
Just happen to have a big roll of fiberglass cloth that I have been waiting to use for something interesting.
 
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