• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.4
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• pp.135-144
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• 2005

The Effects of intake swirl and combustion parameters on the performance and emission characteristics in a V8 type turbocharged intercooler D.I. diesel engine of the displacement $16.7\iota$ were studied experimentally in this paper. Generally the swirl in the combustion process of diesel engine promotes mixing of the injection fuel and the intake air. Also, TCI diesel engine is put to practically use intercooler in order to increase boost efficiency which is cooled boost air. As a result of steady flow test, when the swirl ratio is increased, the mean flow coefficient is decreased, whereas the Gulf factor is increased. And through engine test, its can be effected to meet performance and emission by optimizing the main parameters; the swirl ratio is 2.25, compression ratio is 17.5, combustion bowl is re-entrant $8.5^{\circ}$, nozzle hole diameter is $\phi0.33^{\ast}3+\phi0.35^{\ast}2$, injection timing is BTDC $12^{\circ}CA$ and turbocharger is T02 model which are compressor 0.6A/R+46trim and turbine 1.0A/R+57trim.

• Journal of the korean Society of Automotive Engineers
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• v.13 no.2
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• pp.50-66
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• 1991

There are many factors which influence on the performance of a diesel engine. The piston bowl shape and swirl ratio are important factors to enhance the fuel-air mixing and flame propagation. In this study, calculations of the flow field in the cylinder of the diesel engine were carried out using the CONCHAS-SPRAY code for different bowl shapes and swirl ratios. In the case of constant swirl ratio, vortices which affect fuel-air mixing, evaporation and flame propagation are generated more strongly and consistently in the bowl-piston type combustion chamber than in the flat piston type. With this strong squish effect, injected fuel droplets are widely diffused and rapidly evaporated in the bowl-piston type combustion chamber. Especially a strong squish is developed and large and strong vortices are generated in the edge cutted bowl piston chamber. As the swirl ratio increases, it is found that a large and strong squish and vortices are generated in the combustion chamber and also fuel droplets are diffused into the entire combustion chamber.

• Journal of the Korea Institute of Military Science and Technology
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• v.6 no.4
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• pp.132-144
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• 2003

Numerical analysis of the spray angles of Dual swirl injector were investigated to obtain basic design data and to predict the combustion performance. Using the commercial thermal hydraulic program, discharge coefficients and spray angles were numerically analyzed with recess length, pressure drop, velocity ratio, mixture ratio and back hole length. Water was used as simulants for oxidizer and fuel, respectively to compare the experimental results. Swirl injectors were designed to inject oxidizer of 70.5g/s and fuel of 29.5g/s at the pressure drop of 1MPa and two recess lengths were considered. In addition, the effect of injector geometry coefficient and velocity ratio on the discharge coefficient was studied.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.3
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• pp.99-105
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• 2003

The configuration of intake port is a dominant factor of inlet air flow and mixture formation in an engine. In this study, as an available technology to optimum intake port, the flow box system using resine has been applied. So we presents a methodology for estimating inlet flow characteristics in this paper. This quantified experimental result shows good agreements with visualization data in a cylinder. We obtained the optimal value of swirl ratio and flow coefficient under steady flow rig test for new development of intake port for heavy-duty engine. From this results, the cylinder heat with a good evaluated swirl flow characteristics was developed and adapted for a 11L heavy-duty engine using the liquid phase LPG injection (LPLi) system. This .research expects to clarify major factor that make the intake port efficiently.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1771-1776
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• 2003

The supersonic swirl jet is being extensively used in many diverse fields of industrial processes since those lead to more improved performance, compared with the conventional supersonic no swirl jet. In the present study, an experiment is carried out to investigate the effect of annular swirl jet on the supersonic dual coaxial jet. A convergent-divergent nozzle with a design Mach number of 1.5 is used for the supersonic primary jet, and the sonic nozzles with four tangential inlets are used to make the secondary swirl jet. The primary jet pressure ratio is varied in the range from 3.0 to 7.0 and the outer annular jet pressure ratio is from 1.0 to 4.0. The interactions between the annular swirl and the inner supersonic jet are quantified by the pitot impact and static pressure measurements and visualized by using the Schlieren optical method. The results show that annular swirl jet alters the shock structure and impact pressure distributions compared with no swirl jet.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.430-435
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• 2008

Total lengths of domestic pipe network for district heating system are above about 2,500Km. A lots of pumping power for heat transportation through long pipe are required by the flow friction of pipe surface. Until now there have been considered about various methods to reduce the flow friction for district heating system such as using surfactants and turbulence promoters by swirl flow and baffles etc. At this study, swirl flow generator was tested about the possibility to increase the heat transfer ratio at the heat exchanger in the case which the suppling water temperature increased from $50^{\circ}C$ until $120^{\circ}C$. Experimental results showed that the heat transfer ratio increased and also pressure increase ratio increased simultaneously in the case which swirl flow generator installed. The amount of the increasing ratio for heat transfer and pressure were reached until 4.33% and 11% at the case of $120^{\circ}C$ suppling temperature which domestic district heating system were using.

• Journal of ILASS-Korea
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• v.5 no.3
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• pp.27-36
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• 2000

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.

• Journal of the Korean Society of Propulsion Engineers
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• v.27 no.1
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• pp.27-36
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• 2023

To understand the atomization performance in gas-liquid swirl-coaxial injector applied to a small rocket engine, a cold-flow test was performed by varying the design parameters and supply condition of propellants. As the swirl-chamber diameter and the angle of the convergent section, which are design parameters of injector increased, the spray performance of the injector improved by increasing the swirl strength. In addition, as the gas-liquid momentum-flux ratio increased, the gas flow separated some of the droplets from the liquid film, and a gas-droplet mixture core was formed in the center of the spray sheet.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.6
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• pp.11-17
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• 1996

Many researches on natural gas engines, with lean mixtures are being conducted for the purpose of preservation of global environment. Lean combustion is one of the most promising method for increasing engine efficiency and reducing the emission from SI engines. Due to the possibility of partial burn and misfire, however, under lean burn operation, stable flame kernel formation and fast burn rate, by use of swirl or tumble flow, are needed to guarantee a successful subsequent combustion. Experimental data were obtained on a 4-stroke, natural gas fueled SI engine to investigate the effect of compression ratio, swirl and spark plug electrode rotation on efficiency and emission under lean burn condition. Experimental results have displayed that higher compression ratio, presence of swirl vane and favorable direction of electrode gap brougth about the improvements in engine efficiency and its operational stability.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.10
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• pp.3282-3292
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• 1996

Flow velocity was measured using a hot wire anemometer. Turbulence intensity was in proportion to mean flow velocity regardless of swirl velocity. And integral length scale has proportional relation with swirl velocity regardless of measurement position. Flame speed calculated by radius of visualized flame was increased and then decreased according to lapse of time from spark. Maximum flame speed was increased according to increase of turbulence intensity. Burning speed and flame transport effect increased with increase of swirl velocity, but ratio of burning speed to flame speed decreased with increased of swirl velocity. Mass fraction burned versus volume fraction burned was increased in proportion to the increase of turbulence intensity, caused by increase of combustion promotion effect according to increase of turbulence intensity and scale.