Quote:
Originally Posted by cyclopathic
putting aside discussion on how flawed the study is or isn't it had shown that vortex generators can improve existing aerodynamic features and may produce better results than spoilers alone, when applied properly.
With respect to critique.. Scale is wrong? may well be, if it were a replica of real car. But they used generic "sedan" shape, so wrong comparing to what? "Surface details this small cannot be analysed with anything below a 1/2-scale model" would have been the case if once again we were looking at real car, with panel gaps or window seals or wipers or grills to look at, but on clay model? You can argue that 68.1% drag reduction is unrealistic in real car applications, that if the real car model was used and you were trying to scale result to original. But these arguments just point out the limitations of lab experiment results; it is not like the general principle is invalid.
Perhaps you could make an argument that vortex generators only work at high flow speeds, but this is not a case. The existing applications in aviation on small planes like Cressna had shown that VGs help to reduce wind stall speed from 60 to 45MPH. Well within general car speeds. They also reduced top speed by a couple MPH, so there is no question that VG generate additional drag.
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*You are correct,in that VGs have been shown to reduce overall drag on notchback cars,SUVs,and Vans.
*The Mitsubishi Evo Lancer registered a maximum 1.7% drag reduction with delta-shaped VGs.
*An SUV and van registered 4.2% and 10% reductions respectively in a different investigation by different investigators.
*The Lockheed C-130 Hercules has undergone VG,stubs,nubs,microvane,and sub-B.L. VG drag reduction investigations for its up-swept underside to good effect.
*The report from India was extremely flawed in execution and follow through,but is no reflection on you.