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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 18, Issue 4 - Dec 2013
Volume 18, Issue 3 - Sep 2013
Volume 18, Issue 2 - Jun 2013
Volume 18, Issue 1 - Mar 2013
Selecting the target year
Validation of Digital Holographic Particle Velocity Measurement System
Roh, H.S. ; Kang, B.S. ;
Journal of ILASS-Korea, volume 18, issue 3, 2013, Pages 119~125
DOI : 10.15435/JILASSKR.2013.18.3.119
Digital holographic particle velocity measurement system can be a promising optical tool for the measurements of three dimensional particle velocities. In this research, validation experiments for the digital holographic particle velocity measurement system were conducted with measuring the velocities of glass beads on a rotating disk. Uncertainty analysis was performed to identify the sources of all relevant errors and to evaluate their magnitudes. The measurement results of particle velocities obtained with digital holographic method are compared reasonably well with the known values within acceptable range of errors. Moreover, digital holographic method showed better performance compared with that of optical holographic system.
Effect of Ultrasonic Frequency on the Atomization Characteristics of Single Water Droplet in an Acoustic Levitation Field
Suh, Hyun Kyu ;
Journal of ILASS-Korea, volume 18, issue 3, 2013, Pages 126~131
DOI : 10.15435/JILASSKR.2013.18.3.126
This paper describes the effect of ultrasonic frequency(f) on the atomization and deformation characteristics of single water droplet in an acoustic levitation field. To achieve this, the ultrasonic levitator that can control sound pressure and velocity amplitude by changing frequency was installed, and visualization of single water droplet was conducted with high resolution ICCD and CCD camera. At the same time, atomization and deformation characteristics of single water droplet was studied in terms of normalized droplet diameter(
), droplet diameter(d) variation and droplet volume(V) variation under different ultrasonic frequency(f) conditions. It was revealed that increase of ultrasonic frequency reduces the droplet diameter. Therefore, it is able to levitate with low sound pressure level. It also induces the wide oscillation range, large diameter and volume variation of water droplet. In conclusion, the increase of ultrasonic frequency(f) can enhance the atomization performance of single water droplet.
A Study on Evaluating a Representative Smoke Value from an Inspection Vehicle Using Integration Method over a Cycle of Free-Acceleration Test Mode
Lee, Choong Hoon ;
Journal of ILASS-Korea, volume 18, issue 3, 2013, Pages 132~139
DOI : 10.15435/JILASSKR.2013.18.3.132
Smoke emissions from light duty diesel vehicles were measured using light extinction method with the free acceleration test mode. The smoke emissions for each measurement cycle of the free acceleration method showed large variations according to driver`s pedal pushing pattern. The smoke values for each measurement cycle initially increased and reach a peak value. Integration of the smoke emissions with time for each measurement cycle was performed to get a representative smoke value which was obtained by averaging the integrated results. Two kinds of integration time range were used. One is range over the whole measurement cycle of the free acceleration method. The other is only the acceleration range in the measurement cycle. Overall, variation of the representative smoke values obtained by the integration method was reduced comparing to the traditional representative smoke value which was obtained from a peak smoke value over the measurement cycle. Ten vehicles of the same model with 2.5 liter diesel engines, and seven vehicles of the same model with 2.7 liter diesel engines, were tested using the free acceleration test method.
Disintegration of Cryogenic Jet in Super-critical Environment
Lee, Keonwoong ; Kim, Dohun ; Koo, Jaye ;
Journal of ILASS-Korea, volume 18, issue 3, 2013, Pages 140~145
DOI : 10.15435/JILASSKR.2013.18.3.140
Sub/supercritical spray experiments were conducted, and cryogenic nitrogen and gaseous argon were selected for simulants. liquid nitrogen and gaseous argon were injected in subcritical case, and supercritical nitrogen and near-critical gaseous argon were injected in near-critical/supercritical cases. shadowgraph method was used to visualize spray, and analyzed about the breakup length. The breakup length was measured from numbers of Instantaneous shadowgraph Images from each case, and they were compared with momentum flux ratios and density ratios. It was observed that the relation between breakup length and momentum flux ratio was fitted into former experiment results. and the reasonable constant was suggested about the relation between breakup length and density ratio.
The Flow of a Liquid Film on Spin Coating
Kim, Tae-sung ;
Journal of ILASS-Korea, volume 18, issue 3, 2013, Pages 146~154
DOI : 10.15435/JILASSKR.2013.18.3.146
The flow of a liquid film on spin coating is investigated in the case that the fixed volume of a liquid is placed on the center of a stationary disk. Thin film equations that are well approximated when the characteristic length in the vertical direction is much smaller than that in the radial direction (
) and have already been proposed in the work of T.-S. Kim & M.-U. Kim (2009), are used. The differential equation that governs the free surface of a liquid when
is also derived. The basic flow is analyzed using the thin film equations and their results are compared to the results of Navier-Stokes equations.
Measuring Particle Number from Light-duty Diesel Vehicles in WLTP Driving Cycle
Park, Junhong ; Lee, Jongtae ; Kim, Jeongsoo ; Kim, Sunmoon ; Ahn, Keunhwan ;
Journal of ILASS-Korea, volume 18, issue 3, 2013, Pages 155~160
DOI : 10.15435/JILASSKR.2013.18.3.155
Worldwide harmonized light-duty vehicle test procedure (WLTP) for emission certification has been developed in WP.29 forum in UN ECE since 2007. The test procedure is expected to be applied to Korean light-duty diesel vehicles at the same time of adoption in Europe. The air pollutant emissions from light-duty vehicles have been regulated with weight per distance travelled which means the driving cycles can affect the results. The six Euro-5 light-duty diesel vehicles including sedan, SUV and truck have been tested with WLTP, NEDC which is used for emission certification for light-duty diesel vehicles, and CVS-75 to estimate how much particle number emission can be affected by different driving cycles. The averaged particle number emissions have not shown statistically meaningful difference. The maximum particle number emission have been found in Low speed phase of WLTP which is mainly caused by cooled engine conditions. The amount of particle number emission in cooled engine condition is much different as test vehicles. It means different technical solution is required in this aspect to cope with WLTP driving cycle.