High Velocity Impingement of Single Droplets on a Dry Smooth Surface
| Autor: | Stephan Bansmer, Rolf Radespiel, Michael Hartmann, Thorsten J. Möller, Benjamin Faßmann |
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| Rok vydání: | 2013 |
| Předmět: |
Droplet Impingement
Splashing Materials science Computational Mechanics General Physics and Astronomy High Impact Velocity Substrate (electronics) Deposited Mass Fraction Shadowgraphy symbols.namesake Optics Digital image processing Aerodynamic drag Weber number Droplet Generation on Demand Fluid Flow and Transfer Processes business.industry Reynolds number Secondary Droplet Mechanics Ohnesorge number High Weber Number Mechanics of Materials symbols business Mass fraction |
| Popis: | The vertical impact of single, mono disperse water droplets on a dry smooth surface was studied experimentally by means of shadowgraphy. A glass substrate was mounted on a rotating wheel to obtain high impact velocities. The droplets were generated on demand. While the Ohnesorge number was kept constant, Weber number and Reynolds number were varied by adjusting the impact velocity. In all performed experiments, splashing was observed. The distinction of the different measurement series was done by the use of the Weber number. The different Weber numbers were, 3,500, 5,000 and 10,000. Phase-locked images were taken and the temporal evolution of the impact was reconstructed by means of the nondimensional impingement time. The outcome of the measurement was analysed by digital image processing to quantify the distribution of the diameter of the resulting secondary droplets in size and time as well as their velocity, and the total deposited mass fraction remaining on the surface after the impingement. In all cases, the greater part of the impinging primary droplet remained on the substrate. |
| Databáze: | OpenAIRE |
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