Abstract
The structure, axial concentration decay, and formation of flammable hydrogen-air mixture are studied numerically for a case of hydrogen release from a round nozzle and a plane nozzle with aspect ratio 200. Simulations of the underexpanded hydrogen jet structure for both circular and plane nozzles were conducted using the computational fluid dynamics in two stages: firstly from the nozzle across the shocks’ structure, and secondly downstream from the Mach disk to the far field. The results confirmed the phenomenon of “switching” axes known for plane jets of finite aspect ratio: the faster mixing in the plane of a minor axis makes the jet in this plane wider than in the plane of a major axis. The faster hydrogen-air mixing takes place only in the near field close to the nozzle. Downstream the plane nozzle jet structure tends to reproduce that of the axisymmetric jet. In the far field both plane and round nozzle jets resemble the similarity law for axial concentration decay in round jets.
| Original language | English |
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| Title of host publication | Unknown Host Publication |
| Publisher | Keio University |
| Pages | 1-11 |
| Number of pages | 11 |
| Publication status | Published (in print/issue) - 5 Sept 2010 |
| Event | 8th International Symposium on Hazards, Prevention, and Mitigation of Industrial Explosions - Japan, Yokohama Duration: 5 Sept 2010 → … |
Conference
| Conference | 8th International Symposium on Hazards, Prevention, and Mitigation of Industrial Explosions |
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| Period | 5/09/10 → … |
Keywords
- Hydrogen safety
- underexpanded jet
- plane nozzle
- axial concentration decay