In: Mechanical Engineering
Why is the moment at leading edge(LE)=-c/4 times lift + moment at c/4=-position of center of pressure times lift? The equation shows like this MLE=-c/4*L+Mc/4=-xp*L. Because moment of leading edge and moment at center of pressure or moment at c/4 they always act on the wing but why they equal to each other but not like sum them up? Also, what is neutral point? Is neutral point always change in different situations like flying with different angle of attack? And why the derivative of moment at c/4 of time(d(Mc/4)/dt)=0? Is it because moment at c/4 always constant? Thank you so much