Optimization of constant altitude-constant airspeed flight of turbojet aircraft

Abstract

Then we can deduce: 1) is not negative for all y because of the inequality, Eq. (11), and conditions on y(y) that is, -y(O) > 0 and y(l) = 0; 2) the displacement of the trailing edge h(y) is positive, as far as is positive (Fig. 1); and 3) Eq. (8) implies that c(y) is positive, because both and h(y) are positive. This deduction leads to the conclusion that Eq. (10) is also the sufficient condition of positive c(y). Hence, we obtain the optimum semispan ratio cropt and the optimum drag ratio