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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 5, Issue 4 - Dec 2000
Volume 5, Issue 3 - Sep 2000
Volume 5, Issue 2 - Jun 2000
Volume 5, Issue 1 - Mar 2000
Selecting the target year
Study on the Adaptiveness of Using an Injector As an Expansion Device of Refrigerator
Cho, B.O. ;
Journal of ILASS-Korea, volume 5, issue 3, 2000, Pages 1~8
Spray as a liquid atomization technique has wide applications of combustion, painting, chemical, medical and agricultural purpose, and so on. Capillary tubes and expansion valves, as an expansion device of vapor compression type refrigerators, has been used from the early time. But there are some problems in practice, the former can't control refrigerant flowrate exactly and the later most of imported are expensive relatively and has some difficulties to install. Choosing an injector as a new concept of expansion device of refrigerator in this study to improve such troubles of the coming expansion device, the refrigerant spray behavior and refrigeration characteristics are evaluated experimentally. It is verified that the injector with a good function of refrigerant atomization plays a desirable role of refrigerant expansion in the actual refrigeration cycle.
Precise Air-Fuel Ratio Control on Transient Conditions with the PC-ECU in SI Engine
Yoon, S.H. ;
Journal of ILASS-Korea, volume 5, issue 3, 2000, Pages 9~16
In a SI engine, three-way catalyst converter has the best efficiency when A/F ratio is near the stoichiometry. The feedback control using oxygen sensors in the commercial engine has limits caused by the system delays. So it is necessary to control fuel quantity in accordance with intake air amount in order to reduce exhaust emission and improve the specific fuel consumption. Precise A/F ratio control requires measurement of air amount with respect to the cylinder and injection fuel according to the air amount In this paper, we applied nonlinear fuel injection model and developed the algorithm of A/F ratio control. This algorithm includes the methods of measurement of transient air mass flowing into each cylinder, of calculation of injection pulse width for measured air mass, and the method of feedback and engine control by using lambda sensor. Also we developed control program for IBM-PC by using C++ Builder, and tested it in the commercial engine.
Comparison of Spray Angles of Multihole Port Fuel Gasoline Injector with Different Measuring Methods
Kim, J.H. ; Rhim, J.H. ; No, S.Y. ; Moon, B.S. ;
Journal of ILASS-Korea, volume 5, issue 3, 2000, Pages 17~26
The main parameter commonly used to evaluate spray distribution is spray angle. Spray angle is important because it influences the axial and radial distribution of the fuel. Spray angles were measured and compared for the two non-air assisted injectors such as 2hole-2stream 4hole-1stream injectors used for port fuel injection gasoline engines with n-heptane as a fuel by three different measuring techniques, i.e., digital image processing, shadowgraphy, and spray patternator, respectively. Fuel was injected with the injection pressures of 0.2-0.35 MPa into the room temperature and atmospheric pressure environment. In digital image processing approach, the selection of the transmittance level is critical to obtain the edge of spray and hence to measure the spray angle. From the measurement results by the shadowgraphy technique, it is dear that the spray angle is varied during the spray injection period. The measurement results from spray patternator show that the different spray angles exist in different region. Spray angle increases with the increase in the injection pressure. it is suggested that the spray angle and stream separated angle should be specified when spray is characterized for 2hole-2stream injector, because spray angle is much different though stream separated angle is same. It was also considerably affected by the measurement techniques introduced in this experimental work. However, the optimal axial distance for measuring the spray angle seems to be at least 60-80 mm from the injector tip for two non-air assisted injectors.
A Study of Two-Phase Swirl Spray Characteristics on Dual Airblast Velocity Ratio
Kang, S.J. ; Oh, J.H. ; Song, K.J. ; Rho, B.J. ;
Journal of ILASS-Korea, volume 5, issue 3, 2000, Pages 27~36
In this study, spray characteristics of a dual airblast atomizer are addressed. Three dimensional characteristics of a dual airblast atomizer with air swirl are measured to provide the significant data. The liquid flow rate was fixed at 0.06 kg/min, and atomizing air was controlled at the liquid-air mass ratio of 4.0. The performance of the spray with co-swirl and counter-swirl flow was investigated at each point in the developed spray region using a three-component phase Doppler particle analyzer. This instrument was also used to evaluate the concentration profiles. The three dimensional mean velocity were investigated of present flow characteristics of the dual airblast atomizer. In addition, drop size distributions, mean droplet size profile, and droplet concentration were analyzed to understand atomization characteristics. This experimental results can be conveniently utilized for the preliminary design of gas turbine engines for aircraft.
The effect of gas density on the drop trajectory and drop size distribution in high speed gas stream
Lee, C.H. ;
Journal of ILASS-Korea, volume 5, issue 3, 2000, Pages 37~44
High velocity, gas-assisted liquid drop trajectories were investigated under well-controlled experimental conditions at elevated gas densities and room temperature. A monodisperse stream of drops which are generated by a vibrating-orifice drop generator were injected into a transverse high velocity gas stream. The gas density and air jet velocity were adjusted independently to keep the Weber numbers constant. The Weber numbers studied were 72, 148, 270, 532. The range of experimental conditions included studied the three drop breakup regimes previously referred as bag, stretching/thinning and catastrophic breakup regimes. High-magnification photography and conventional spray field photographs were taken to study the microscopic breakup mechanisms and the drop trajectories in high velocity gas flow fields, respectively. The parent drop trajectories were affected by the gas density and the gas jet velocities and do not show similarity with respect to the either Weber or the Reynolds number, as expected.
Effects of Electrostatic Force on Movement of Sprayed Aerosol Particles in Continuous Galvanizing Process
Kim, S.H. ; Kim, H.M. ; Chung, H.C. ; Chung, W.S. ;
Journal of ILASS-Korea, volume 5, issue 3, 2000, Pages 45~54
A novel electrostatic splaying method for solidifying a galvanized coating layer was studied. Our experimental results and computer simulations showed that electric field could assist the fine droplets to attach on the steel surface and change the sprayed droplets trajectory especially in the space near the steel surface. It was necessary to apply the electric voltage higher than - 20 kV to obtain the enough electrostatic attraction force between droplets and the steel sheet.