Transactions of the Korean Society of Automotive Engineers (한국자동차공학회논문집)
- Volume 2 Issue 4
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- Pages.100-111
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- 1994
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- 1225-6382(pISSN)
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- 2234-0149(eISSN)
Observations on the Near-Nozzle Behavior of an Unsteady Fuel Spray
노즐부근에서의 비정상분무 거동
Abstract
Observations on the near-nozzle behavior of an unsteady fuel spray through single cylindrical hole nozzle were made by phase Doopler anemometer and microphotographs. At the edge of the spray, droplet velocity peaked during needle opening and closing. Droplet sizes tended to be small on the edge of spray. The near-nozzle spray angle taken from the microphotographs was time-dependent, even though it increased with gas-to-liquid density ratio as expected. The near-nozzle spray angle was the greatest on the initial stage and decreased to a relatively constant value after about one third of the total injection duration regardless of the ambient gas conditions, even in the near-vaccum condition. The wider near-nozzle spray angle in the early stage is due to the flow characteristics inside the nozzle rather than aerodynamic interactions. However, once the spray was established, aerodynamic interactions are essential in the near-nozzle atomization.
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