Blow-off process of highly under-expanded hydrogen non-premixed jet flame
| Autor: | Shohei Yamamoto, Keiji Takeno, Ryo Sakatsume |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Hydrogen Astrophysics::High Energy Astrophysical Phenomena Nozzle Base (geometry) Energy Engineering and Power Technology chemistry.chemical_element 02 engineering and technology Edge (geometry) Physics::Fluid Dynamics 0502 economics and business Physics::Chemical Physics 050207 economics Jet (fluid) Range (particle radiation) Renewable Energy Sustainability and the Environment 05 social sciences Process (computing) Mechanics 021001 nanoscience & nanotechnology Condensed Matter Physics Fuel Technology chemistry Reservoir pressure High Energy Physics::Experiment 0210 nano-technology |
| Zdroj: | International Journal of Hydrogen Energy. 43:5199-5205 |
| ISSN: | 0360-3199 |
| DOI: | 10.1016/j.ijhydene.2018.01.116 |
| Popis: | Relationships between flame lift-off heights and reservoir pressure were experimentally investigated in order to clarify blow-off process of hydrogen non-premixed jet flames with a highly under-expanded jet structure. In this study, straight nozzles with diameters of 0.34, 0.53, 0.75 and 1.12 mm were used with maximum reservoir pressure for spouting hydrogen of 13.2 MPa. Experimental results are shown that lift-off heights in stable under-expanded jet flames do not vary significantly and are independent of the reservoir pressure in the range of studied pressure. However, the lifted heights are affected by the nozzle diameters and become smaller as the nozzle diameters increase. From experimental results, the condition for the blow-off process of under-expanded subsonic jet flames was proposed. It was concluded that the under-expanded jet flame could be blown off when the maximum waistline position, where radial distance from the jet axis to an elliptic stoichiometric contour reaches its maximum comes closer to the nozzle exit than the edge of the jet flame base. |
| Databáze: | OpenAIRE |
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