Quote:
Originally Posted by LibertyMKiii
The 2,400 mph comment is that in relation to wind tunnel testing? I was hoping multiple 150mph related leaf blowers might do the job.
I have had some issues with suspension, which I will not get into. The world record holder did not have suspension.
My current setup which I believe is great uses aftermarket A-Arms which are high in nylon content and solid links in replacement of the shock/spring combo. The Nylon A-Arm acts lick a spring itself yet is very stiff also. There is also some give in the BSR foam tire. I previously had some very stiff springs rated around 25lbs each and with the down force of my front splitter the front chassis was scraping.
Here is an image of the current setup. I need to get over to my friends house with a TIG welder and adapt the "shock tower" to have the shock mount be lower and more directly over that location. This should help reduce the frontal area.
I had a great image showing c/d ratings related to the bottom of the car's height off the ground but at 3.5 cm I do not believe there is much room there to take advantage of significant air flow?
-Liberty |
There is a concept in fluid mechanics called dynamic similarity,or,verisimilitude.It has to do with maintaining a super-critical Reynolds number,as would be encountered with a full-scale vehicle.
As you scale down with models you must increase air velocity accordingly,in order to maintain a constant Reynolds number,or else the boundary layer conditions will be totally wrong,giving false measurements.
With your RC racer so small,in order to maintain the proper Reynolds number you'd have to have an airspeed in the supersonic range;which introduces compressibility effects you wouldn't normally encounter.
If I were you,I'd write a letter or email to Cal Tech,addressed to the folks who operate the GALCIT wind tunnel,and see if they could offer some advise.
They've done the testing for many land speed record vehicles,motorcycles and cars.
Sometimes,grad students will take a race car on as a graduate research project and help underwrite expenses.