Simultaneous Analysis of the Dispersed Liquid and the Bulk Gas Phase of Water Sprays Using Raman Spectroscopy

• Published in: Applied spectroscopy Vol. 70; no. 6; pp. 1055 - 1062
• Main Authors: Schuster, Julian Jonathan, Siegler, Philipp, Guenther, Astrid, Wirth, Karl-Ernst, Braeuer, Andreas Siegfried
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01-06-2016
• Subjects: Droplets; Entrainment; Evaporation; Liquids; Sprayers; Sprays; Thermodynamic equilibrium; Water sprays; water sprays; Raman spectroscopy; droplet temperature; heat- and mass-transport
• DOI: 10.1177/0003702816641562
• EISSN: 1943-3530
• ISSN: 0003-7028

Currently, a comprehensive physical description of sprays is not possible, as the involved heat- and mass-transport mechanisms have not yet been understood completely. Therefore, we here show and apply a straightforward Raman evaluation technique which simultaneously probes spatially resolved (i) droplet temperature, (ii) evaporation progress and (iii) entrainment of air into the spray. First, the working principle of the Raman technique and the calibration of the sensor are described. Then, the applicability of the Raman technique is demonstrated showing example measurement results obtained from a superheated water spray. The plausibility of the obtained measurement results is demonstrated comparing them with computations for thermodynamic equilibrium conditions. Information about the droplet temperature, the evaporation progress and the entrainment of air might complement the insights into heat- and mass-transport mechanisms which can already be provided applying other existing optical spray diagnostic techniques.