Turbulence Structure in a Free Bubbly Jet: Analysis of Higher-Order Statistical Moments of Velocity Fluctuations
A. S. Severin1,2, M. V. Timoshevskiy1, B. B. Ilyushin1, K. S. Pervunin3
1Kutateladze Institute of Thermophysics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
2Novosibirsk National Research State University, Novosibirsk, Russia
3Imperial College London, London, UK
Keywords: free jet, bubbles, gas fraction, turbulence, velocity fluctuations, flow structure, higher-order moments, PIV method, statistical filtering
Abstract
This paper presents the results of a statistical analysis of the turbulent structure in a free bubbly jet at a Reynolds number of 12500 based on PIV measurements of the carrier-phase velocity. The distributions of higher-order statistical moments for velocity fluctuations (skewness and excess coefficients) and the energy spectra of turbulence for single-phase and gas-saturated jets were obtained after applying the procedure of statistical filtering to instantaneous velocity fields. The influence of the dispersed phase (bubbles with an average diameter of 0.8 mm) with a volume gas fraction of 0, 1, 2, and 3% for the specified characteristics of the continuous phase was analyzed.
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