Simultaneous 3D Laser Doppler Velocimeter (LDV) measurements in the wake of bluff bodies

Turbulence fluctuations were measured in the near and far wake of a nonaxisymmetric blunt afterbody by a 3D, 3 color laser Doppler velocimeter. Results show that this velocimeter is operational and capable of measuring small velocities compared to the freestream velocity. Data obtained behind an afterbody including a triangular base show that this system can provide information of flowfields of three-dimensional nature. However, since there is an increase in the amount of information in 3D flow, further data reduction and complementary analysis are needed to reconstruct the entire velocity field and to clarify the different accuracy of the velocity components, especially in order to explain the difference of turbulence level observed at the stations where z is different from zero.