Quote:
Originally Posted by M_a_t_t
Can you cancel induced drag from lift by increasing downforce or is the induced drag from each treated like an absolute number?
|
Lift/downforce are basically just a continuum (like thrust /drag). A positive upwards force is called lift, and a positive downwards force is called downforce.
Think of it like this. The upper surfaces of the car are developing (mostly) lift - upwards forces. To counteract that, we need to have forces that pull in the opposite direction - downwards. If, overall, 'up' is greater than 'down', we have 'lift'. If, overall, 'down' is greater than 'up', we have 'downforce'.
So we might do things that create down forces (eg a rear wing), but unless those down forces are greater than the up forces, we will still have overall lift.
Lowest induced drag comes from having neither lift or downforce. Therefore, if you can reduce lift without doing anything that at the same time increases drag, you're on a winner. (Dick Barnard, the aerodynamicist I worked with on the book, had a good example. He said,"A fence placed across the roof will reduce lift. But it will also massively increase drag!")
The easiest way of reducing lift without adding extra drag is a full length undertray and rear diffuser.