investigations of tu rbulence statistics in the laboratory model of an atmospheric cloud

Investigations of turbulence statistics in the laboratory model of an atmospheric cloud

P.M. Korczyk, F. Lusseyran, T.A. Kowalewski, S. P. Malinowski

• „Warm rain initiation problem”

• Lack of high resolution measurements of cloud droplets turbulence interactions.

Motivation

Cloudy, saturated air (blue)Clear, unsaturated air (white)Evaporating droplets

Motivation

cloud chamber

light sheet

laser

camera

cloud during mixing

Small chamber with droplet generator

Experimental setup

Particle Image Velocimetry

Particle Image Velocimetry

Sample from first image

Interrogation area

Correlation matrix

Particle Image Velocimetry

First Image

Second Image

First Image

Deformed first Image

Velocity field

Velocity field

PIV processing

Deformation

Particle Image Velocimetry

Particle Image Velocimetry

Long sequence PIV

Stereo PIV

Stereo PIV

VidPIV ILA

Stereo PIV – comparison of VidPIV and Opflow

Statistics of fluctuations

Second order longitudinal strucure function

Energy dissipation rate

Kolmogorov length