EQXX diffuser in extended mode this text?:
The diffuser is actually 2.8-degrees upsweep, beginning at 252mm,before the rear wheels.
Have done today more simulations got the ground level working which raise the numbers:
Here is the latests takeoffs. More in the facebook where is more pics:
Added today the EQXX front to model Cd 0,194 with 82mm ground clearance. Here angle of attack 0,5 degrees and diffusor at 5 degree
EQXX full siluette -10mm lowered at the rear. plus same treats as the original EQXX shape. Cd is still better than eqxx basic shape with Cd 0,188 vs without front Cd 0,177. Difference 5,8%
EQXX full siluette -10mm ground clearance 130mm (was 82mm on previous simulations) Cd 0,189. So increasing the ground clearance does not impact the drag a lot in the base body. When you add rotating wheels the lowering has almost linear drop in drag.
Ok here is my first guess how the underside should be done. Now I know from drag studies that straigth diffuser is not best for low drag so I have just adapted the roof curvature in the diffuser. Cd with this 0,184 which is pretty nice drop from 0,188. EQXX original diffusor angle is not 5 degree because in range mode it extends and lowers the angle to around 2,5 degrees. I do MK2 version to see if the upper dip style helps also underside and ofcourse the EQXX style with and without the extension for comparison.
The dip in diffusor seem to work also underside Cd 0,182. Good for two counts again just a guess on the dimensions. My guess with tweaking the shapes on curved diffusor you would get 0,01 lower drag than the 5 degree straigth diffusor.
