[trebuchet03]

Originally Posted by Deezler

Treb, thanks. Good Info. I will not deny that I'm a total aero newb.

When it comes to this like turbulence - no one really "knows" We can just make OK to decent guesses

Originally Posted by Deezler

You seem to imply that the Lancer, with its steeper angle, relies more on the latter. Being to steep for flow attachment, they were going for a clean break, so to speak. However, they apply VG's to trip flow down the rear glass! So my logic is this: If you have any flow detachment, and you can positively offset this with a simple trick like VG's, why not? I would think your ability to run simulations to examine this could be a perfect test of this idea.

I didn't mean to imply what the design goal was for the lancer. I just wanted to make sure that we don't directly compare one car to another because they are both sedans (or similar in that nature).

VG's are band aids. They are to be added as afterthoughts because you screwed up in designing (or compromised which resulted in less than optimal aero). As my design goals are to completely avoid the situation of flow detachment, VG's won't be really of any use to me UNLESS the vehicle is so long that the boundary layer just gets to fat and lazy

That said, I'm not abandoning doing cfd runs on VG's I think they're interesting and potentially useful for someone that isn't going as far as I am. Weather or not my CFD is of any help is a completely different subject matter. I'm working to the best of my knowledge/experience/tools

And I should say that I'm not for nor against VG's. My preference is for the "better" overall design. I am, however, against "blind" placement of VG's. I also feel that VG's, in some situations, can be placed properly such that there is no additional frontal area added. Which may be the case for the Jetta depending on the height

Originally Posted by Deezler

The Jetta angle is less, but from your own simulations we still see that the speed of air decreases as you move down the rear glass. Perhaps the Lancer angle being more severe made a trick like this necessary where it could have little benefit on a Jetta.

I really can't speculate on that - but that reasoning isn't unreasonable.

Originally Posted by Deezler

While its getting hard to keep track off all the pretty pictures thus far, a simple goal, in my mind, could be this: Minimize the total amount of blue behind the vehicle, and replace the green on the trunk lid with yellow.
I don't know the scales on the Mitsu pics as compared to yours, but they seem to have done just that with the application of the VG's.

When I'm done compiling the numbers - we'll have a better method of comparing subtle differences. It's taking some time because I'm adding more stuff to the results list

Originally Posted by Deezler

Whats up with the fusion model? Can you normalize that one to those done for the Jetta (i.e. same background flow color)? It seems to have perfect flow over the entire vehicle.

Do'H, I forgot to include a total velocity cut plot It does have pretty good flow over the top There is a small section where velocity slows down, but I wouldn't really call it separation (especially when compared to the Jetta)....