MEASUREMENT OF TURBULENCE IN PRESSURIZED PIPE FLOW USING PARTICLE IMAGE VELOCIMETRY

Abstract: Invasive mussel species can cause problems at a variety of water resource facilities by colonizing within piping systems, significantly reducing flow capacity. Exposing mussels to intense turbulence as they enter the system may be effective in reducing mussel settlement downstream. To quantify turbulence in a pressurized pipe, Particle Image Velocimetry (PIV) measurements were made downstream of a newly developed pipe fitting designed to generate intense turbulence for mussel control. Two-dimensional (2D) velocity data were collected throughout the pipe profile at various distances downstream of the fitting and were analyzed to quantify hydrodynamic properties of the turbulent flow including dissipation rate and Kolmogorov length scale. Results indicate that the fitting generated sufficient turbulent energy to drive the microscale length down to scales expected to influence invasive mussel species (near 200 µm). Spectral analysis of spatial data also revealed that near the Kolmogorov scale, energy was increased by more than one order of magnitude for a mean pipe velocity of 0.914 m/s and just less than one order of magnitude for 1.83 m/s