This is great! =D>
I also do model aircraft stuff and had to smile seeing the propellers. I ever wanted to build my own windtunnel. It was a dream of mine a long time but never did it.
Also tried to help a friend of mine with some aero tweaks on his 1/8 flat track. And we noticed that the aero balance could really make quite a huge difference controlling the car at about 80 - 120 kph.
Today I´m pretty into this aerodynamic stuff and working with a windtunnel and CFD. And I can tell you sometimes the big guys also have problems getting accurate results.
I think even your self made windtunnel can give you lots of informations.
I like to tell some words how the big guys are doing their windtunnels. I don´t want to critisize your project. You really did a great job, but maybe this helps you a bit.
- The propeller is pulling behind the measuring track, this reduces turbulence and makes the air hitting the test object more homogenous.
- The section where you straighten the air is usually much bigger in area and behind this is a nozzle that contract and accelerate the air. The cross section difference from start to end during the nozzle is about 10 and more. This is a bit hidden in most pictures but very important to get clean air (if you are interested, google a bit and you will find many pictures).
- Measuring tracks for cars mostly have walls with slots when the walls are near to the car. Open tracks are resulting in less drag in comparison to real life and closed have to much drag and lift the car (less downforce is measured).
And because I read you look out for ground effect: This is a very sensitive area!
My tip is to smaller the gaps where the scale comes through the ground. Otherwise lots of air will be sucked through and destroy the pressure distribution under the car.
Hope you have lots of fun with aerodynamic science
EDIT:
Just noticed you don´t need to straigten the air if you have a decent nozzle and put the props behind the measure track.
But thank you for the link. Didn´t know about.
