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ATTENUATION OF HOMOGENEOUS AND ISOTROPIC TURBULENCE BY SOLID PARTICLES

Wontae Hwang
GE Global Research, 1 Research Circle, Niskayuna, NY 12309, USA

John K. Eaton
Dept. of Mechanical Engineering Stanford University 488 Panama Mall Stanford, CA 94305 USA

Resumo

The interaction of a dilute dispersion of small heavy particles with homogeneous and isotropic air turbulence has been investigated. Stationary turbulence (at Taylor micro-scale Reynolds number of 230) with small mean flow was created in a nearly-spherical sealed chamber by means of eight synthetic jet actuators. Two-dimensional particle image velocimetry was used to measure fluid velocities in the presence of spherical glass particles that had diameters similar to the Kolmogorov length scale of the flow. The experiments were conducted in two different environments, the laboratory (with gravity) and NASA's KC-135 (without gravity). The laboratory experiments showed that the particles attenuated the fluid turbulence kinetic energy (up to 35 − 40%) and viscous dissipation rate (up to 40 − 50%) with increasing mass loadings (up to 30%). The micro-gravity experiments showed that the absence of particle potential energy loss and particle wakes caused greater levels of turbulence attenuation since there was no additional production due to mean particle motion.