Turbulent Flow Measurements of Microalgal Cell Suspension in Bubble Column Bioreactors

Abstract

During cultivation of a microalga Chlorella in a bubble column and a split-cylinder airlift, turbulence characteristics were measured using a constant temperature anemometer equipped with a hot film sensor. From the digitized output signal of the anemometer, such parameters as the mean liquid phase velocity, turbulence intensity, integral scale, and turbulent diffusivity were calculated. The non-dimensional power spectrum distributions of liquid velocity fluctuations fit well with the equation which assumes that the correlation function of turbulent velocity fluctuations is exponential.