Numerical simulation on syphonage effect of laval nozzle for low pressure cold spray system
| Autor: | Daming Gu, Hongren Wang, Xiangbo Li, Lukuo Xing, Guosheng Huang |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Chemistry
Nozzle Flow (psychology) Metals and Alloys Gas dynamic cold spray Mechanical engineering Mechanics Discharge coefficient Industrial and Manufacturing Engineering Computer Science Applications Spray nozzle Modeling and Simulation Service life Ceramics and Composites Mass flow rate Supersonic speed |
| Zdroj: | Journal of Materials Processing Technology. 214:2497-2504 |
| ISSN: | 0924-0136 |
| DOI: | 10.1016/j.jmatprotec.2014.05.014 |
| Popis: | Instead of injected by high pressure powder feeder, powders can be drawn into the nozzle by syphonage effect generated by supersonic gas flow in low pressure cold spray. This characteristic makes low pressure cold spray conveniently for on-site operation. However, no data have ever been reported on the relationship between the nozzle structures and the gas flow in the powder feeder pipe. In this paper, a CFD software (STAR CCM+) was used to calculate the gas flow in nozzle of the DYMET 413 commercial low pressure cold spray system. Variation of structures and process parameters based on the commercial system were also investigated. The syphonage effect is strongly influenced by the powder feeding location, the temperature and pressure in prechamber has little effect on syphonage effect in powder feeder pipe. The syphonaged gas will decelerate the gas velocity and low down the gas temperature in nozzle, so it is best to control the mass flow rate of powder feeding gas by selecting the location. One of the disadvantages is that the particles will collide with the nozzle wall which makes the nozzle a short service life. |
| Databáze: | OpenAIRE |
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