| Abstract: | In the cited work 1], a variational problem of the minimum power required to obtain a given thrust for a wing with a surface able to vibrate in a supersonic flow is considered. In the present work the theoretical maximum efficiency in a subsonic flow of bodies whose shape can be simulated by unsteady sources is found. For axisymmetric bodies a shape is found giving an efficiency as close as required to the theoretical limit. The results obtained make it possible to evaluate possible improvements not only of artificial devices but also of living creatures, since they move at subsonic speeds.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 4, pp. 128–132, July–August, 1984. |
