A novel laboratory apparatus for simulating isotropic oceanic turbulence at low Reynolds number

Abstract

A new experimental apparatus to simulate oceanic turbulence at low Reynolds number in the laboratory is described. Actuators located at each corner of a cubic Plexiglas box generated synthetic jets that interacted to create turbulent flow at the center of the saltwater apparatus. Four turbulent intensity levels were established, and velocity measurements were performed using digital particle image velocimetry. The flow characteristics in the center of the apparatus were confirmed to be nearly isotropic and homogeneous. The range of the dissipation rate (10−3 to 1 cm2s−3) and the Kolmogorov microscale (0.03 to 0.2 cm) agreed well with natural oceanic environments in the coastal zone, and the length scales and magnitude of the velocity and strain rate fluctuations were appropriate for zooplankton studies. The flow characteristics compared favorably with previous approaches for generating turbulence in the laboratory, in particular, oscillating‐grid apparatus. The current design also possessed increased simplicity, controllability, and transportability. Future objectives include studying the behavioral response of zooplankton to turbulent fluid motions.