Cloud cavitation vortex shedding inside an injector nozzle
| Autor: | V. Stamboliyski, K.S. Nikas, I.K. Karathanassis, Nicholas Mitroglou, Manolis Gavaises |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Fluid Flow and Transfer Processes
Materials science Mechanical Engineering General Chemical Engineering Nozzle Aerospace Engineering Reynolds number 02 engineering and technology Mechanics Vortex shedding 01 natural sciences 010305 fluids & plasmas Vortex Lift (force) symbols.namesake 020303 mechanical engineering & transports 0203 mechanical engineering Nuclear Energy and Engineering Cavitation 0103 physical sciences symbols Strouhal number TJ Body orifice |
| Zdroj: | Experimental Thermal and Fluid Science. 84:179-189 |
| ISSN: | 0894-1777 |
| DOI: | 10.1016/j.expthermflusci.2017.02.011 |
| Popis: | The development and collapse of cloud cavitation and its link to surface erosion within a transparent test single-orifice nozzle operating with a closed Diesel fuel hydraulic circuit, has been characterized using high-speed imaging. Data have been obtained for a range of cavitation and Reynolds numbers under fixed lift positions. Post processing of a large number of images acquired with short exposure time (1 μs) allowed the elucidation of the distinct flow phenomena associated with the highly transient two-phase flow. At the inlet of the flow orifice, the vapour cloud was found to occupy the largest part of the nozzle hole cross-section. Coherent vortical structures of a hairpin shape have been detected to onset at the closure region of this vapour cloud and shed downstream in a fully transient manner. The effect of the operating parameters on the temporal and spatial characteristics with regards to the emergence and collapse of the hairpin vortices has been quantified. It has been established that the cavitation-vortex shedding was taking place in a periodical manner, characterized by a Strouhal number. |
| Databáze: | OpenAIRE |
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