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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 20, Issue 4 - Dec 2015
Volume 20, Issue 3 - Sep 2015
Volume 20, Issue 2 - Jun 2015
Volume 20, Issue 1 - Mar 2015
Selecting the target year
Effects of Fuel Composition on Flame Transfer Function in Lean Premixed Combustor
Kim, Jinah ; Kim, Jihwan ; Lee, Jeongwon ; Kim, Daesik ;
Journal of ILASS-Korea, volume 20, issue 3, 2015, Pages 135~140
DOI : 10.15435/JILASSKR.2015.20.3.135
Flame transfer function is used to determine the relationship between flow fluctuations and heat release perturbations in a lean premixed gas turbine combustor. The characteristics of flame transfer function are known to depend greatly on flame geometries in addition to other various flow conditions. However, it is not easy to experimentally measure the flame transfer function under various actual combustor operating conditions in terms of time and cost. The current research tries to model the flame transfer function using CFD(Computational Fluid Dynamics). From the results, it is shown that the calculated steady flame geometry can be exactly captured with consideration of the wall heat transfer and radiations. Also, unsteady analysis results show the close characteristics of the flame transfer function to the measured one in both gain and phase.
A Study on Combustion Characteristics of Spark-Ignited Engine with Different Late Intake Valve Closing for Miller Cycle
Chung, J.H. ; Kang, S.J. ; Kim, J.S. ; Jeong, S.C. ; Lee, J.W. ;
Journal of ILASS-Korea, volume 20, issue 3, 2015, Pages 141~148
DOI : 10.15435/JILASSKR.2015.20.3.141
In order to research engine characteristics of spark-ignited engine with intake valve closing timing change for Miller cycle, two cam for LIVC(Late Intake Valve Closing) were designed and fabricated an prototype valvetrain. And intake valve closing timing were adjusted to build low compressing and high expansion cycle for HEV. In experimental study, it were investigated with different engine speed, spark timing and air-fuel ratio to compare base cam and LIVC cam type. It was found that the volumetry efficiency and effective work of compression process were decreased in case of LIVC cam. When compared with the existing results, the maximum pressure in the cylinder was reduced about 12~13 bar and the volumetric efficiency was reduced about 16%.
Comparison on Exhaust Gas of Heavy Duty Diesel Trucks; THC and CO Emission Affected by NO
Control Devices (EGR, SCR)
Mun, SunHee ; Yoo, Heung-Min ; Son, JiHwan ; Yun, Changwan ; Park, Gyu Tae ; Kim, JeongSoo ; Lee, Jongtae ;
Journal of ILASS-Korea, volume 20, issue 3, 2015, Pages 149~155
DOI : 10.15435/JILASSKR.2015.20.3.149
With increasing of GDP, the registration number of passenger cars has exceeded 20 million last year in Korea. Especially, the registration number of the diesel engine vehicles has been increasing. However, the WHO(World Health Organization) IARC (International Agency for Research on Cancer) has reported that diesel engine exhaust gas is an one of HAPs, which has carcinogenic for human, and they have designated it to Group 1. To solve this problem, exhaust gas from diesel engines has to be controlled. Thus, it has been controlling by European regulatory standard in Korea. On the other hand, in order to meet the enhanced emission regulations, all manufacturing company applied
control device to vehicles such as EGR (Exhaust Gas Recirculation), SCR (Selective Catalytic Reduction) and so on. However, these devices (EGR, SCR) were operated by difference reaction mechanism respectively, and the composition of exhaust gas would be differenced from that of them. In this study, it was conducted to evaluate variety characteristics on changing of exhaust gas composition by each
control device, and the heavy duty diesel trucks were chosen as experimental vehicles. From the result, it revealed that vehicles (with EGR) were discharged higher THC as 52.5% than that of others (with SCR). However, it did not followed that trend, in the case of CO; it was discharged as 57.2% lower than that of others (with SCR). In the future, these data would be used to apply to efficient
control device for meeting to EURO 6.
The Effect of Dual Clutch Transmissions on the Stability Emissions Characteristic in a Gasoline Direct Injection Engine
Kim, Kwang Lae ; Roh, Hyun Gu ;
Journal of ILASS-Korea, volume 20, issue 3, 2015, Pages 156~161
DOI : 10.15435/JILASSKR.2015.20.3.156
This paper described the effect of dual clutch transmissions on the stability emissions characteristic in a GDI engine at vehicle Inspection and Maintenance(I/M) program. In order to investigate the influence of direct injection gasoline engine with DCT, the experimental apparatus consisted of GDI engine with 4 cylinder, dynamometer and exhaust emissions analyzer. Analyzed emission gas include CO, HC and NOx results that DCT vehicle in the case of NOx, HC in automatic transmission vehicles less than 1/2 level was confirmed to be exhausted. However vehicle specific power increases CO also has increased.
Effect of Atomization Characteristics of Twin Fluid Nozzle on Urea Pyrolysis
Ku, Kun Woo ; Chung, Kyung Yul ; Yoon, Hyun Jin ; Seok, Ji Kwon ; Hong, Jung Goo ;
Journal of ILASS-Korea, volume 20, issue 3, 2015, Pages 162~167
DOI : 10.15435/JILASSKR.2015.20.3.162
Recently, there has been rising interest in applying urea-SCR systems to large marine diesel engines because the International Maritime Organization (IMO) has decided to enforce NOx reduction regulations. Generally, in the case of urea-SCR of the marine diesel engine, a type of twin fluid atomizer has been using for injection of the urea solution. This study conducted to investigate an effect of the atomization of external-mixing twin fluid nozzle on the conversion efficiency of reductant. The lab-scaled experiment device was installed to mimic the urea-SCR system of the marine diesel engine for this study. In a low temperature inflow gas condition which is similar with the exhaust temperature of large marine diesel engine, this study found that the conversion efficiency of reductant of when relative big size urea solution droplets are injected into exhaust gas stream can be larger than that of when small size urea solution droplets are injected. According to results of this study, the reason was associated with decrease of reaction rate constant caused from temperature drop of inflow gas by assist air of twin fluid atomizer.
A Study on Dynamic Characteristics of Gas Centered Swirl Coaxial Injector with Acoustic Excitation by Varying Momentum Flux Ratio
Lee, Jungho ; Park, Gujeong ; Yoon, Youngbin ;
Journal of ILASS-Korea, volume 20, issue 3, 2015, Pages 168~174
DOI : 10.15435/JILASSKR.2015.20.3.168
Combustion instability is critical problem in developing liquid rocket engine. There have been many efforts to solve this problem. In this study, the method was sought through the injector as part of these efforts to suppress combustion instability. If the injector can suppress the disturbance coming from the supply line as a kind of buffer it will serve to reduce combustion instability. Especially we target at gas propellant oscillation in gas-centered swirl coaxial injector. The phenomenon is simulated with acoustic excitation of speaker. The film thickness response at injector exit was measured by using a liquid film electrode. Also the response of spray to the disturbance was observed by high-speed photography. Gas-liquid momentum flux ratio and the frequency of feeding gas oscillation were changed to investigate the effect of these experimental parameters. The trend of response by varying these parameters and the cause of weak points was studied to suggest the better design of injector for suppressing combustion instability.
An Experimental Study on the Droplet Size Distribution of Sprinkler Spray for Residential Building
Kim, Sung Chan ; Kim, Jung Yong ;
Journal of ILASS-Korea, volume 20, issue 3, 2015, Pages 175~180
DOI : 10.15435/JILASSKR.2015.20.3.175
A series of sprinkler discharging tests was conducted to measure the droplet size and its distribution of residential fire sprinkler heads. Droplet sizes in sprinkler spray were measured using a laser diffraction method for the flush, circular and pendent type sprinkler head. In this study, the
of the flush type sprinkler heads were ranged between
and those of circular and pendent type were
, respectively. The measured cumulative volume distributions were followed by a combination of the log-normal and Rosin-Rammler distribution which is widely used in the computational fire analysis and the parameters of distribution function were obtained from the best fit line through the measured data.
Wetting Characteristic of Single Droplet Impinging on Hole-Patterned Texture Surfaces
Moon, Joo Hyun ; Lee, Sangmin ; Jung, Jung-Yeul ; Lee, Seong Hyuk ;
Journal of ILASS-Korea, volume 20, issue 3, 2015, Pages 181~186
DOI : 10.15435/JILASSKR.2015.20.3.181
This study presents the dynamic wetting characteristics of an impact droplet on hole-patterned textured surfaces. The flat surfaces were manufactured by a drilling machine to generate the micro-order holes, leading to make the surface hydrophobic. Other flat surfaces were fabricated by the anodizing technique to make hydrophilic texture surfaces with a nanometer order. For hydrophilic and hydrophobic textured surfaces with similar texture area fractions, the impinging droplet experiments were conducted and compared with flat surface cases. As results, an anodized textured surface decreases apparent equilibrium contact angle and increases contact diameters, because of increase in contact area and surface energy. This is attributed to more penetration inside holes from larger capillary pressure on nanometer-order holes. On the other hand, temporal evolution of the contact diameter is smaller for the hydrophobic textured surface from less penetration on the micro-order holes.
Schlieren, Shadowgraph, Mie-scattering Visualization of Diesel and Gasoline Sprays under GDCI Engine Low Load Condition
Park, Stephen Sungsan ; Kim, Donghoon ; Bae, Choongsik ;
Journal of ILASS-Korea, volume 20, issue 3, 2015, Pages 187~194
DOI : 10.15435/JILASSKR.2015.20.3.187
In this study, three visualization methods, Schlieren, Shadowgraph, and Mie-scattering, were applied to compare diesel and gasoline spray structures. Fuels were injected into a high pressure/high temperature constant volume chamber under the same ambient pressure and temperature condition of low load in gasoline direct injection compression ignition (GDCI) engine. Two injection pressures (40 and 80 MPa), two ambient pressures (4.2 and 1.7 MPa), and two ambient temperatures (908 and 677 K) were use. The images from the different methods were overlapped to show liquid and vapor phases more clearly. It was found that the gasoline fuel is more appropriate to form a lean mixture.
A Comprehensive Study on Fuel Injector Test Bench for Heavy Duty Engine
Das, Shubhra Kanti ; Thongchai, Sakda ; Lim, Ocktaeck ;
Journal of ILASS-Korea, volume 20, issue 3, 2015, Pages 195~201
DOI : 10.15435/JILASSKR.2015.20.3.195
This study discusses a fuel injector test bench containing a mechanical type fuel supply system for heavy duty diesel engine. The main focus of this study was to evaluate the design stability of the test bench, which basically measures the injector durability of a multi-hole heavy duty injector by using pure diesel as a test fuel. In this experiment, diesel spray was controlled by a specially designed control box and all the experiments were carried out to measure e.g. fuel injection pressure and fuel injection quantity to understand the injection status which is interlinked with the stability factor of total test bench design. Also, the durability test was performed to understand the heavy duty operation lastingness of the designed system and the flow rate of the installed distributor pump in the fuel supply system of this studying test bench was compared with LO-1 and LO-2 pump. The results of the above mention tests revealed that the injector test bench design and control system can serve the purpose for heavy duty injector.