Dynamic Soaring in Shear Wind Regions Associated with Jet Streams

Abstract

Dynamic soaring enables an energy gain by transferring energy from the moving air in a horizontal shear wind region to the saiplane.  There are shear wind regions associated with jet streams, extending from the jet stream core with its high wind speed to the altitude where the air is at rest.  The possibility of utilizing this energy gain is considered for the dynamic soaring of sailplanes.  An efficient optimization procedure is used to determine the minimum shear wind strength which is required for the dynamic soaring flight manoeuvre, applying a realistic mathematical model for describing the dynamics of a sailplane.  It turns out that the minimum shear wind strength is smaller than the values which can be encountered in existing shear wind regions associated with jet streams.  As a result, the performance capability of modern sailplanes offers the possibility for dynamic soaring in these jet stream regions.

Presented at the XXVIII OSTIV Congress, Eskilstuna, Sweden, 8-15 June 2006