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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of ILASS-Korea
Journal Basic Information
Journal DOI :
Institute for Liquid Atomization and Spray Systems-Korea
Editor in Chief :
Volume & Issues
Volume 1, Issue 4 - Dec 1996
Volume 1, Issue 3 - Sep 1996
Volume 1, Issue 2 - Jun 1996
Volume 1, Issue 1 - Mar 1996
Selecting the target year
Atomization of fuel in Diesel Engines (I)
Lee, Chang-Sik ;
Journal of ILASS-Korea, volume 1, issue 2, 1996, Pages 1~7
The Spray Behavior Analysis and Space Distribution of Mixture in Transient Jet Impinging on Piston Cavity
Lee, S.S. ; Kim, K.M. ; Kim, B.G. ; Chang, S.S. ; Ha, J.Y. ;
Journal of ILASS-Korea, volume 1, issue 2, 1996, Pages 16~23
In case of a high-speed D.I. diesel engine. the injected fuel spray is unavoidable that the impinging on the wall of piston cavity and in this case the geometry of piston cavity has a great influence on the atomization structure and air flow fields. In the field of combustion and in many other spray applications, there are clear evidence of correlation between spray structure and emission of pollutants. Ordinary, the combustion chamber of driving engine have unsteady turbulent flow be attendant on such as the change of temperature, velocity and pressure. So the analysis of spray behavior is difficult. In this study, a single spray was impinged on each cavity wall at indicated angle in a quiescent atmosphere at room temperature and pressure, as being the simplest case, and 3 types of piston cavity such as Dish, Toroidal and Re-entrant type was tested for analyzing the influence of cavity geometry. And hot wire probe was used for analyze non-steady flow characteristics of impinging spray, and to investigate the behavior of spray, the aspects of concentration c(t), standard deviation
and variation factor (v.f.) was measured with the lapse of time.
Analysis of Impingement Lands to Help Diesel Combustion Chamber Using Spray Impaction
Park, K. ;
Journal of ILASS-Korea, volume 1, issue 2, 1996, Pages 24~32
Most of the research of small engines to date focused on developing spark ignition engines occupied much parts. Recently the number of a small direct injection diesel engine applied in small cars has been increased and considered as a next generation power source for passenger cars because of its high efficiency. Therefore the combustion chamber becomes smaller and the fuel injection pressure goes higher, which makes fuel sprays impinged easily on the combustion chamber walls. When strong swirls are not induced, the fuel may not mix with air because of fuel deposition on the wall. As a positive way, the combustion chamber systems which is using spray wall impaction has been introduced and assessed by an experimental or a simulate manner. In these systems the raised lands are positioned in tile chamber for spray impaction in order to break up the fuel drops into much smaller and direct them into desirable direction. This study addresses to the effects of rho position and size of the raised land or glow plug to help the chamber design using spray wall impaction. The characteristics of the spray impinged on various lands are investigated and compared with each other. Then the chamber shapes are discussed with the characteristics and their proper position and size is proposed in any chamber volume.
A Study on the Spray and Fuel-Film Formation Mechanism of MPI Injector
Lee, K.H. ; Lee, C.S. ; Kim, B.K. ; Sung, B.K. ;
Journal of ILASS-Korea, volume 1, issue 2, 1996, Pages 33~41
Mixture formation is one of the important factors to improve combustion performance of MPI gasoline engines. This is affected by spray and atomization characteristics of injector. Especially, in the case of EGI system, air-fuel mixing period is too short and formed a lot of fuel-film in the intake manifold and cylinder wall. This fuel-film is not burnt in cylinder, it is exhausted in the form of HC emission. In this paper, spray characteristics such as size distributions, SMD, and spray angle are measured by PMAS, and the fuel-film measuring device is developed specially. Using this device, the amount and distribution of fuel-film which flows into through valve can be measured Quantitatively. As the result of these experiments, the information of optimal spray characteristics and injection condition that minimize the fuel-film can be built up.
Spray Characteristics of a Pilot Nozzle in a Counter-Swirl Type Gas Turbine Combustor
Ko, Y.S. ; Kim, M.H. ; Kim, D.J. ; Min, D.K. ; Chung, S.H. ;
Journal of ILASS-Korea, volume 1, issue 2, 1996, Pages 42~49
The structure of sprays from a simplex type pilot nozzle atomizer is studied experimentally by measuring velocities, Sauter mean diameter, and number density. Interaction of the spray with gas-phase flow field generated from a 1 MW range industrial gas turbine combustor adopt ing a counter-swirler is investigated. Various spray behaviors are reported. Especially interest ing characteristics are the tangential motion of the spray and of the spray with swirl interaction. It shows a Rankine combined vortex type of velocity characteristics, having linear velocity profile inside the inner core whole small particles exist and rapidly decreasing velocity profiles outside. Interacting spray has relatively uniform number density profiles compared to the nozzle spray itself.
A Study on the Characteristics of Gasoline Engine Performance Equipped with Perforated Throttle Valve
Cho, B.O. ; Lee, C.S. ;
Journal of ILASS-Korea, volume 1, issue 2, 1996, Pages 50~56
In an fuel injection type gasoline engine, atomization of fuel droplet and mixture formation process are very important to understand engine combustion efficiency, and also has influence directly on the decision of engine performance and pollutant emission. In this study, perforated throttle valve instead of solid type throttle valve was developed and equipped to an SPI engine to promote secondary atomization and good droplet-air mixture formation. From the engine performance lest. it was verified that the case of perforated valve kas more advantages in each experimental parameters such as in cylinder gas pressure, mass burnt ratio, fuel consumption rate, and pollutant emission characteristics than that of solid one equipped. No matter what the same perforated valve, there are some distinct results in engine performance characteristics according to the perforate ratio.
A Numerical Study on Air-Assisted Breakup of Fuel Droplets
Hwang, S.S. ;
Journal of ILASS-Korea, volume 1, issue 2, 1996, Pages 57~65
Breakup models are evaluated using the experimental drop trajectory ill this study. The experimental conditions corespond to Weber # 56, 260, 463. Computations are carried out using a modified KIVA-II program with 2 different breakup submodel(TAB and Wave breakup model) and dynamic drag model which the drag coefficient changes dynamically with distortion parameter. Results show that computation with wave breakup model represents the experimental drop trajectory better than that with TAB submodel. And result with wave breakup model shows similar breakup pattern to experimental breakup process. It is thought that in wave breakup model the small drops are shed from the parent drop throughout parcel lifetime such thai this modelling represents the real breakup process well.
Phenomena of Liquid Jet Breakup in High Speed Gas Stream
Park, Y.K. ; Seok, J.K. ; Lee, C.W. ;
Journal of ILASS-Korea, volume 1, issue 2, 1996, Pages 66~73
The present study investigates experimentally the characteristics of liquid jet, which is, the spray flow in the normal direction of the air stream under the flow conditions of air velocity
. The present study adopts with the flow visualization technique using a short duration light bulb and the image processing analyse with CCD camera. Two types of injector were used: one is a flat plate type, and the other is backward facing step type, which height are 5, 8, 10mm. Dispersion of liquid jet can be represented by gray level of CCD camera. In the upstream of liquid jet, the backward facing step shows better liquid jet penetration. However, in the downstream. mean droplet size for backward facing step injector is smaller than that for flat plate injector