Transactions of the Korean Society of Mechanical Engineers (대한기계학회논문집)
- Volume 18 Issue 4
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- Pages.1039-1049
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- 1994
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- 1225-5963(pISSN)
DOI QR Code
Phase Doppler Measurements and Probability Density Functions in Liquid Fuel Spray
연료분무의 위상도플러 측정과 확률밀도함수의 도출
Abstract
The intermitternt and transient fuel spray have been investigated from the simultaneous measurement of droplet sizes and velocities by using Phase/Doppler Particle Analyzer(PDPA). Measurement have been done on the spray axis and at the edge of the spray near nozzle at various gas-to-liquid density ratios(.rho./sub g//.rho./sub l/) that ranges from those found in free atmospheric jets to conditions typical of diesel engines. Probability density distributions of the droplet size and velocity were obtained from raw data and mathematical probability density functions which can fit the experimental distribations were extracted using the principle of maximum likelihood. In the near nozzle region on the spray axis, droplet sizes ranged from the lower limit of the measurement system to the order of nozzle diameter for all (.rho./sub g/ /.rho./sub l/) and droplet sizes tended to be small on the spray edge. At the edge of spray, average droplet velocity peaked during needle opening and needle closing. The rms intensity is greatly incresed as the radial distance from the nozzle is increased. The probability density function which can best fit the physical breakage process such as breakup of fuel drops is exponecially decreasing log-hypebolic function with 4 parameters.
Keywords
- Fuel Spray;
- Droplet Size;
- Droplet Velocity;
- Phase/Doppler Particle Analyzer;
- Probability Density Distribution and function;
- Log-Hyperbolic Function
- 연료분무;
- 액적크기;
- 액적속도;
- 위상도플러 입자측정기;
- 확률밀도분포 및 함수;
- 쌍곡선함수;