Cookie Cutter Cars as a Result of Aerodynamics

[serialk11r]

Originally Posted by Cd

If Toyota tested the Lexus LS 430 in the same tunnel as the Prius, then that would mean it has a Cd of .26 versus .30 for the Insight.

So the LS 430 could be four counts better than the Insight !

Thats a lot of freedom for designers between the two shapes.

I think looking at various MBs and the Lexus LS is pretty telling. You don't need a good overall shape to get to the 0.25 range, you just have to tweak the small details very carefully.

That said a good tail and greenhouse is definitely helpful, Porsche 911s do pretty well in the wind tunnel for their 285 tires and huge radiators, and the Nissan GTR has a pretty low Cd despite the wing. I think in a few years ~0.25Cd will be pretty standard, and we'll see more cars close to 0.20.

[aerohead]

If a member,or friend or family of a member had one of the LS 430s,we could get it into the A2 Tunnel and see if we got 0.26.It would be a good validation.
Also,if the United States had their own national wind tunnel,all cars sold could be independently-verified.
If every man,woman,and child in the US donated a 3-Dollar bill,it would be enough to finance the construction easily.
Suppose we could do the same for a supercomputer for Direct Numerical Simulations.Mercedes-Benz says that it takes about 2-days to do the full Navier-Stokes 3D CFD analysis,and that it is within 1% accuracy,compared to a full-scale tunnel test at critical Reynolds Number.
About 182 vehicles could be analyzed numerically each year.
I'd be happy to drop $6 for the 2-pack.

[Cd]

Originally Posted by Cd

I call bull on all cars having to look identical due to aerodynamics.
As an example, just look at the Gen 1 Insight and the Lexus LS430 - both have the exact same Cd.
There are plenty of areas for the stylist to do whatever they want.

I got to thinking of how I worded this comment, and I realized that it could be taken as rude and offensive.
I didn't intend for this comment to be aimed at anyone here, and was 'just sayin' how that I think it's a lame excuse for auto manufacturers to give the excuse of all cars having to look the same to be aerodynamic.

So, sorry if I offended anyone here.

I just saw the new Toyoda ( ) Camry and it's aero styling.
While it is indeed getting closer to the template shape, i can't say i find anything wrong with that in my eye. The closer a car is to that shape, the more beauty i see ! .

YKYAEM when you see this picture of the Camry grille and say " oooooh ...nice grille block Toyota ! " ( And just think - even more of that open area will be blocked by the license plate.

[aerohead]

Yeah,in Europe,the wider plates would essentially close off the entire center section.

[ChazInMT]

Originally Posted by Cd

I got to thinking of how I worded this comment, and I realized that it could be taken as rude and offensive.
I didn't intend for this comment to be aimed at anyone here, and was 'just sayin' how that I think it's a lame excuse for auto manufacturers to give the excuse of all cars having to look the same to be aerodynamic.

So, sorry if I offended anyone here.

Cd, yer awesome man, I know what you meant!!! Never thought twice about it, we're just sittin here havin a beer talking crap and you said your piece. I thought in many ways you were right too.

Much Respect!
Charlie

[user removed]

I know I'm warped, Mom describes me as DEEP. She always was good with the Spartan application of wordmanship. The heck with .25, I want .15 and I don't care what the "stylists" do after that.

I do really like the concept of the inflatable ENERGY ABSORBING boattail. Only thing is the $%^&* tailgaters would be even closer.

I smell ROAD TRAINS.

regards
mech

[Frank Lee]

Originally Posted by aerohead

Also,if the United States had their own national wind tunnel,all cars sold could be independently-verified.
If every man,woman,and child in the US donated a 3-Dollar bill,it would be enough to finance the construction easily.

Once upon a time I posted that the U.S. Gummint funds certain FOREIGN aerodynamicists, the idea being to give them something to do besides develop military hardware (can't find it now). So every man, woman, and child in the U.S. IS donating for aerodynamic development in wind tunnels... it's just that WE CAN'T ACCESS IT FOR OURSELVES.

[Cd]

Armchair CFD is just around the corner. Before we know it, wind tunnels will be used only rarely to verify the CFD simulations.

Think of the energy savings alone by going to CFD ! I think it was Aerohead that mentioned that when one of the big wind tunnels gets used, it draws so much power that they have to verify it with the power grid before the test.
Imagine doing that same test on a laptop, and making small aero changes, simultaneously as the test is running !

Imagine how cool it's going to be to have the computer predict what the car body needs in a certain area to reduce turbulence.

The future is going to be great. ( That's what so bad about dying - you miss out on all the cool stuff ! )

[serialk11r]

Just around the corner? Probably not. There are no remotely efficient algorithms for computing Navier Stokes numerically. Computing power available has increased a thousandfold since they started using CFD.

It would be groundbreaking if someone figured out even an O(exp(n)) time way to do this, so I heard.

Considering the expense of building wind tunnels and supercomputers, it might be better to just give a few hundred million in grants to PDE and numerical analysis researchers. That would be a *lot* of funding. For better or for worse, academic mathematicians are pretty cheap.