jagunx51 wrote:
re-posting:
which one is more effective ......under / above exhaust monkey seat related to current car's design ? how are they related to diffuser-flow extraction ? (simplified drawing)
http://imageshack.com/a/img822/8647/0e2u.jpg
It depends and an answer isn't as clear cut:
-A winglet underneath the exhaust will help in an upwards-bending exhaust gasses flow, benefiting the upwash effect and thus interacting between diffuser and rear wing, BUT because the exhaust flow is low pressure and you blowing it on top of the winglet, you are not creating downforce with it, even inducing lift.
-A monkey seay above the exhaust will make it create extra downforce since you are blowing the low pressure exhaust underneath the wing. The exhaust flow will tend to follow the upwards bending pattern of the winglet due coanda effect, but will be less effective then the other solution, thus the upwash effect will be less. And of course a full fletched monkey seat creates more drag then a simple winglet tucked in behind existing bodywork.