Go to the main menu
Skip to content
Go to bottom
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 13, Issue 4 - Dec 2008
Volume 13, Issue 3 - Sep 2008
Volume 13, Issue 2 - Jun 2008
Volume 13, Issue 1 - Mar 2008
Selecting the target year
Prediction of Maximum Liquid-phase Penetration in Diesel Spray: A review
No, Soo-Young ;
Journal of ILASS-Korea, volume 13, issue 3, 2008, Pages 117~125
The correlations for the prediction of maximum liquid-phase penetration in diesel spray are reviewed in this study. The existing models developed for the prediction of maximum liquid-phase penetration can be categorized as the zero-dimensional (empirical) model, the multi-dimensional model and the other model. The existing zero-dimensional model can be classified into four groups and the existing multidimensional models can be classified into three groups. The other model includes holistic hydraulic and spray model. The maximum liquid-phase penetration is mainly affected by nozzle diameter, fuel volatility, injection pressure, ambient gas pressure, ambient gas density and fuel temperature. In the case of empirical correlations incorporated with spray angle, the predicted results will be different according to the selection of correlation for spray angle. The research for the effect of boiling point temperatures on maximum liquid-phase penetration is required. In the case of multidimensional model, there exist problems of the grid and spray sub-models dependency effects.
Effect of Swirl Angle on the Atomization Characteristics in Twin-Fluid Nozzle with Dual Air Supplying
Woo, J.M. ; Kim, E.S. ; Kim, D.J. ; Lee, J.K. ;
Journal of ILASS-Korea, volume 13, issue 3, 2008, Pages 126~133
The atomization characteristics of the dual air supplying two-fluid nozzle were investigated experimentally using PIV and PDA systems. The twin-fluid nozzle is composed of three main parts: the feeding injector to supply fluid that is controlled by a PWM (pulse-width modulation) mode, the adaptor as a device with the ports for supplying the carrier and assist air, and the main nozzle to produce sprays. The main nozzle has the swirler with four equally spaced tangential slots, which gives the injecting fluid an angular momentum. The swirl angle in the swirler varied with
. The ratios of carrier air to assist air and ALR (total air to liquid) were 0.55 and 1.23, respectively. The macroscopic behavior of the spray was investigated using PIV system, and the AMD and SMD distributions of the sprays were measured using PDA system. As a result, the SMD distribution increases along the radial distance, and it decreases with the increase of swirl angle in swirler.
Effect of Nozzle Cap Geometry for Swirl-Type Two-Fluid Nozzle on the Spray Characteristics
Choi, Y.J. ; Kang, S.M. ; Kim, D.J. ; Lee, J.K. ;
Journal of ILASS-Korea, volume 13, issue 3, 2008, Pages 134~142
In the case of heavy duty diesel engines, the Urea-SCR system is currently considered to reduce the NOx emission as a proved technology, and it is widely studied to get the high performance and durability. However, the nozzles to inject the urea-water solution into the exhaust pipe occur some problems, including the nozzle clogging, deposition of urea-water solution on the inner wall of the exhaust pipe, resulting in the production of urea salt. In this study, a swirl-type twin-fluid nozzle to produce more fine droplets was used as a method to solve the problems. The effect of the nozzle cap geometry, including the length to diameter ratio (
) and chamfer, on the spray characteristics were investigated experimentally. The length to diameter ratio of nozzle cap were varied from 0.25 to 1.125. The chamfer angle of the nozzle cap was constant at 90o. The mean velocity and droplet size distributions of the spray were measured using a 2-D PDA (phase Doppler analyzer) system, and the spray half-width, AMD (arithmetic mean diameter) and SMD (Sauter mean diameter) were analyzed. At result, The larger length to diameter ratio of nozzle cap were more small SMD and AMD. The effect of the chamfer did increase the radial velocity, while it did not affect the atomization effect.
Correlation of Droplet Flow Rate and Spray Cooling Heat Transfer in Forced Convection and Nucleate Boiling Region
Kim, Yeung-Chan ;
Journal of ILASS-Korea, volume 13, issue 3, 2008, Pages 143~148
In the present study, the correlation between the Nusselt number and Reynolds number was developed for forced convection and nucleate boiling region in spray cooling. Also the effect of droplet subcooling on spray cooling heat transfer was investigated. Full cone spray nozzles were employed for spray cooling experiment, and water and FC-77 were used for developing the correlation. From the experimental results, the correlation between the Nusselt number and Reynolds number based on droplet-flow-rate was developed. The correlation shows good predictions with
error for water and FC-77.
Spray Characteristics of the Rotary Atomizer for the Slinger Combustor
Choi, Hyun-Kyung ; Lee, Dong-Hun ; You, Gyung-Won ; Choi, Seong-Man ;
Journal of ILASS-Korea, volume 13, issue 3, 2008, Pages 149~155
An experimental study was performed to understand spray characteristics of the rotary atomizer for the slinger combustor. In this fuel injection system, fuel is injected and atomized in the combustor by centrifugal forces to engine shaft. The experimental apparatus consists of a high speed rotational spindle, rotary atomizer, pressure tank and acrylic case. The droplet size and velocity were measured by PDPA (phase Doppler particle analyzer), and spray was visualized by using high speed camera and Nd:Yag laser-based flash photography. From the test results, the droplet size (SMD) is largely affected by rotational speed, mass flow rate and the number of orifice. As the experimental results, we could understand the spray characteristics of the rotary atomizer for the slinger combustor and obtain the optimum shape of the rotary atomizer which is suitable for the small gas turbine engine.
Numerical Study on the Change in Fire Characteristic as Operating Water-mist in Under-ventilated Compartments
Ko, G.H. ; Lee, S.H. ; Ryou, H.S. ;
Journal of ILASS-Korea, volume 13, issue 3, 2008, Pages 156~161
The present article reports a numerical study on the fire characteristic change by water-mist in under-ventilated compartments. The natural gas and heptane pool fires are used as fire sources, which are located in the bottom center of the 2/5 reduced-scaled model of the ISO 9705 standard room. The fire modeling using the FDS (Fire Dynamics Simulator) is validated by comparison with previously published experimental results. For temperature and combustion gas concentrations at two positions located in the upper layer of compartment, the predicted results with and without water-mist are compared each other. The results show that under the water-mist operation, the predicted temperature and carbon monoxide concentration reduce as
and about 20%, respectively, compared to those without water-mist.