Mean Rise-Rate of Droplets in Isotropic Turbulence Available to Purchase

This paper investigates the rise-rate of droplets that are slightly lighter than the surrounding fluid. We experimentally investigate the effect of three parameters: Stokes number, turbulence intensity and droplet Reynolds number. Droplets were injected into a chamber with nearly isotropic turbulence and little mean flow. The results show that at high turbulence intensity, the mean droplet rise-rate is 25% of the rms velocity regardless of the Stokes number, while at low turbulence intensity, the droplets rise at a rate equal to the rise-rate in a quiescent fluid. At intermediate turbulence intensity, the rise-rate is strongly dependent on the Stokes number.