Question

The formula for SEP is given by ___________

(a) [FN-D]\(\frac{V}{W}=\frac{d}{dt}\Big\{H+\frac{V^2}{2g}\Big\}\)

(b) [FN+D]\(\frac{V}{W}=\frac{d}{dt}\Big\{H+\frac{V^2}{2g}\Big\}\)

(c) [FN-D]\(\frac{V}{W}=\frac{d}{dt}\Big\{H-\frac{V^2}{2g}\Big\}\)

(d) [FN+D]\(\frac{V}{W}=\frac{d}{dt}\Big\{H-\frac{V^2}{2g}\Big\}\)

I had been asked this question by my college director while I was bunking the class.

The above asked question is from High Performance Climb in section Climb and Descent Performance of Aircraft Performance

Answer 1

Right choice is (a) [FN-D]\(\frac{V}{W}=\frac{d}{dt}\Big\{H+\frac{V^2}{2g}\Big\}\)

Explanation: The formula for SEP is given by [FN-D]\(\frac{V}{W}=\frac{d}{dt}\Big\{H+\frac{V^2}{2g}\Big\}\) where FN is force, D is drag, H is height, V is velocity, g is acceleration due to gravitation. SEP stands for specific excess power. It is equal to the rate of change of specific total energy (STE) and is used to increase the total energy of the aircraft which is in a combination with climb and acceleration.