Further Laser Velocimeter Measurements of Slender-Body Wake Vortices.

摘要

The flow over an ogive-cylinder model with a length-to-diameter ratio of seven has been investigated at incompressible flow speeds. Forces and moments, surface flow visualization, and three-dimensional laser velocimeter measurements have been obtained a pitch angles of 22.5 and 37.5 deg. Forces and moments have been compared to data previously obtained over a wide range of Reynolds numbers with this model. Surface flow visualization shows a complicated pattern of multiple separation and attachment lines. Asymmetric breaks in the primary separation lines are believed to be associated with the tearing loose of attached vortex sheets and the subsequent formation of a new sheet. Three-dimensional laser velocimeter measurements were performed on the leeward side of the model at several cross sections and at X = 2.8, 4.9, and 6.3 for alpha = 371/2 deg. Vortical regions rapdily become more and more diffusive and asymmetric in nature with downstream distance. Crossflow vector plots do not show distinct vortex centers toward the rear of the model. (Author)