Investigation of aero-mechanical jitter on a hemispherical turret
Matthew Kalensky, Brian Catron, Stanislav Gordeyev, Eric Jumper, Matthew R. Kemnetz
Abstract
Optical measurements of a hemispherical turret were conducted in both a wind tunnel and airborne testing environment to measure aero-mechanical jitter imposed onto a laser beam. A hemispherical turret was positioned in the freestream flow at various protrusion distances, Mach numbers, and azimuthal angles. Lasers and accelerometers were used to quantify the mechanical contamination imposed onto the beam due to the fluid-structure interaction of the incoming freestream flow and the protruding turret body. The results from wind tunnel and in-flight testing were compared. It was shown that the wind tunnel and in-flight tests yielded different results both quantitatively and qualitatively. The possible reasons for the discrepancies between these testing campaigns were also discussed.