Aircraft propulsion 2nd edition by SAEED FAROKHI" p.340
Aircraft propulsion 2nd edition by SAEED FAROKHI" p.123
As we can see from the image, the nacelle slightly converges towards a throat, before diverging. Why?
Is it to produce the lip thrust force? If so, is that force independent of the diffuser thrust (i.e., the internal pressure rise in the diverging section) ?
And if the cowl lip represents an airfoil operating at a negative angle of attack, shouldnt the "lip thrust" be in the opposite direction?