Vorticity Measurements in Turbulent Soap Films

Abstract
Measurements of vorticity fluctuations are carried out in rapidly flowing turbulent soap films driven by gravity. Isotropic turbulence is generated by inserting one-dimensional grids through the film. The vorticity fluctuations are measured using two optical-fiber velocimeters capable of measuring the fluctuations of both the longitudinal and transverse components of the velocity simultaneously. Our results indicate scaling of the vorticity spectrum, yet this scaling is different from what is predicted theoretically.