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2086 |
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Effects of radial liquid injection on atmospheric plasma characteristics |
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Dennis Soysal / German Aerospace Center (DLR - Deutsches Zentrum für Luft- und Raumfahrt), Germany Asif Ansar / German Aerospace Center (DLR), Germany Tatiana Kavka/ Institute of Plasma Physics, Czech Republic Johannes Arnold/ German Aerospace Center (DLR), Germany |
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The development of submicronic and nano structured materials and deposits by plasma spraying using liquid feedstock have gained significant importance in recent years. Suspension plasma spraying and solution precursor plasma spraying have been investigated in term of process understanding as well for the coatings for applications such as TBCs, solid oxide fuel cells, etc. Introduction of liquid feedstock, however, brings along additional disturbance to the plasma jet and a meticulous control over the injection conditions and the treatment of the droplets in the plasma becomes of critical importance. This work presents recent developments at DLR to characterize the influence of liquid injection on atmospheric plasmas. DLR developed different diagnostic tools to measure the influence of the injection properties on the efficiency of the whole process. A shadowgraphy and a Schlieren system illustrate the trajectory of liquid droplets in the plasma and the solvent vapour around it. The enthalpy field distribution of TriplexPro 200© plasma torch was measured without and with liquid injection by TEKNA Enthalpy Probe Plasma Diagnostics System©. Liquid was injected with a solid stream nozzle with different set of plasma parameters and liquid flow rates. Enthalpy probe measurements were done downstream along the jet axis. Demineralised water was used as a liquid and its effect on the enthalpy was measured for different flow rates. |