Piston-Expansion-Tube Videos Showing Droplet Evaporation

<p>Both videos show high speed recordings of the spontaneous condensation of small droplets of homogeneous size after rapidly expanding a cylindrical volume. After the expansion and droplet creation, the heat of the walls is evaporating the droplets again. The cameras optical axis is oriented parallel to the cylinder axis. A small square area of 8.5 mm side length next to the cylindrical wall is recorded. The particles are illuminated by a laser sheet of about 0.5 mm thickness. The recording frequency is 500 Hz.</p> <p>height/depht of the cylinder: 0.021 m<br> radius of the cylinder: 0.035 m<br> gas: Nitrogen<br> condensing component: n-Propanol<br> gas temperature before expansion: 299.0 K<br> cylinder inner surface temperature: 299.0 K<br> pressure before expansion: 1.0E5 Pa<br> pressure past espansion: 0.55E5 Pa<br> partial pressure of condensing component before expansion: 628 Pa<br> droplet radius past expansion: 100E-9 m</p> <p>Video 5E12nuclei.mp4:</p> <p>droplet concentration: 5E12 1/m&sup3; (rough estimation)</p> <p>Video 8E10nuclei.mp4:</p> <p>droplet concentration: 8E10 1/m&sup3; (counted in one of the video frames)</p> <p>The two different droplet concentrations are achieved solely by the speed of the expansion. The higher the speed, the more nuclei will be created.</p> <p>For more information see <a href="https://doi.org/10.5281/zenodo.4449246">https://doi.org/10.5281/zenodo.4449246</a> (diploma thesis, German language).</p>