Considerations on Laminar Flow for a Stratospheric Airship Platform
Th. Lutz, P. Funk, A. Jakobi and S. Wagner
Proceedings 3rd International Airship Convention and Exhibition, Friedrichshafen, July 1-5, 2000
One important design aspect of stratospheric airship platforms is to maximize the aerodynamic performance especially if high design speeds are aspired. Previous investigations have shown that for the relevant Reynolds number regime, laminarization of the hull may offer a high drag reduction potential in comparison to conventional turbulent designs. Extended laminar flow, however, can only be realized in practice, if severe requirements are met. The parameters influencing transition, like freestream disturbances or surface roughness and accuracy, are being discussed with respect to LTA vehicles operating at stratospheric conditions. It becomes evident that serious basic research is needed in order to improve the understanding of the physical effects which are relevant for the present problem.