Kinetic Energy in Dynamic Soaring—Inertial Speed and Airspeed

Kinetic energy concepts used for dynamic soaring are dealt with and analyzed with regard to their validity and usefulness. One kinetic energy concept is related to inertial speed and the other to airspeed. Using their common basis given by the fundamental equations of motion, each of the two kinetic energy concepts is developed and evaluated. It is shown for both concepts which are the forces that exert an energetic effect and how they influence the kinetic energy state. This is achieved with findings generally valid and with results obtained by computation. In a comparative analysis, both kinetic energy concepts are discussed and assessed, with the result that they are complementary to each other and of equal significance for describing energy harvesting. As a result, it is shown that the concepts of kinetic energy related to airspeed and to inertial speed are equivalent. Thus, both kinetic energy concepts are useful to the effect that the findings and results are of equal value.