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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of ILASS-Korea
Journal Basic Information
Journal DOI :
Institute for Liquid Atomization and Spray Systems-Korea
Editor in Chief :
Volume & Issues
Volume 3, Issue 4 - Dec 1998
Volume 3, Issue 3 - Sep 1998
Volume 3, Issue 2 - Jun 1998
Volume 3, Issue 1 - Mar 1998
Selecting the target year
A numerical analysis and experimental study on the prediction of spray characteristics
Yoon, S.J. ; Cho, D.J. ;
Journal of ILASS-Korea, volume 3, issue 2, 1998, Pages 1~13
A theoretical and experimental study was carried out to predict the drop size distribution of the pressure swirl atomizer. Various analytical methods using the Kelvin-Helmholtz instability theory were tried to examine the wave growth on cylindrical liquid sheets. Cylinderical liquid sheets were extended to the case with the conical sheets. Perturbations due to tangential motion as well as longitudinal one were taken into account. And it was assumed that the breakup occurs when amplitude ratio exceeds exp(12), drop sizes were predicted only by theoretical approach. Drop size distribution was obtained by using maximum entropy formalism. Seven constraints in the form of the definition of mean diameter were used in this formulation in order to avoid the difficulties of estimating source terms. In this study
only was introduced into the formulation as a constraint. The predicted drop size and drop size distribution agreed well with the measured data.
A Study on the High-Efficiency Atomisation Molten Materials (PART 2 : A Study on the Mechanism of Liquid Supplying and Film Formation by Applying the Ejector Principle)
Oh, J.G. ; Cho, I.Y. ;
Journal of ILASS-Korea, volume 3, issue 2, 1998, Pages 14~23
The negative pressure as much as 10's mmHg is demanded at nozzle inside, in case of atomizing the large density molten materials. by conventional air jet nozzle. In this study, suction type fluid nozzle is designed by applying the ejector principle in order to clarify the air flow of nozzle inside, mechanism of liquid suction and liquid film formation. The results of this experimental study areas follows. Suction force of liquid is magnified by using liquid nozzle, and it is able to supply the liquid stable. Negative pressure at nozzle inside is varied by throttle angle of liquid nozzle, position and outer diameter of air jet nozzle, and have a influence on liquid suction quantity and liquid film formation.
Simulation of Fuel Injection System and Model of Spray Behavior in Liquefied Butane
Kim, J.H. ; Koo, J.Y. ;
Journal of ILASS-Korea, volume 3, issue 2, 1998, Pages 24~33
The characteristics of liquefied butane spray are expected to be different from conventional diesel fuel spray, because a kind of flash boiling spray is expected when the back pressure is below the saturation vapor pressure of the butane(0.23MPa at
). An accumulator type pintle injector and its fuel delivery system has been simulated in ruder to give injection pressure, needle lift and rate of fuel injected. The governing equation were solved by finite difference metho. The injection duration was controlled by solenoid valve. Spray behaviors such as a transient spray tip penetration, spray angle and SMD were calculated based on the empirical correlations in case that the back pressure is both above the vapor pressure of the butane and below that of butane. When the back preassure is below the vapor pressure of the fuel, conventional correlation is modified to represent the effect of flash boiling.
An effect of initial disturbance on the breakup mechanism of liquid jet
Seok, J.K. ; Park, Y.K. ; Lee, C.W. ;
Journal of ILASS-Korea, volume 3, issue 2, 1998, Pages 34~41
The present experimental study investigates the effect of an initial disturbance on the breakup mechanism of a liquid column. With varying the maginitude of the inital disturbance, we measure the surface wave of liquid column with adopting laser shadow method and analyze the growth rate of liquid column and breakup frequency. The experimental results show that thebreakup characteristics of liquid column is significantly influenced by the frequency of the initial disturbance. We concluded that the most uniform droplet occurs when the frequency of initial disturbance coincides with the natural frequency of the liquid column.
Velocity and Spray Characteristics under Swirl Flows in a Model Combustor
Bae, C.S. ; Lee, D.H. ;
Journal of ILASS-Korea, volume 3, issue 2, 1998, Pages 42~50
The effect of swirl flows un the fuel spray characteristics were investigated for various swillers in a model combustor. The interaction between the flow field and fuel spray in the main combustion tone made by frontal devices including fuel injection nozzles and swirlers. which were characterized by flow velocities, fuel droplet sizes and their distributions which were measured by APV(Adaptive Phase/Doppler Velocimetry) under atmospheric condition at 320cc/min kerosine fuel flow and 0.04kg/sec air supply. A dual swirler with circumferential two-stage swirl vanes of
vanes in different directions and two single-stage swillers of
vanes with 12 and 16 vanes were tested. It was found that the dual swirler has the largest recirculating zone with highest reverse flow velocity. The strongest swirl flow was found at the boundary of recirculation zone. Small fuel droplets were observed in the main axial stream and inside the recirculation zone when swirling flow field were generated by the frontal devices. These findings could give the tips on the optimal design of frontal devices to realize low emissions in gas turbine combustion.