• Journal of the korean Society of Automotive Engineers
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• v.11 no.2
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• pp.34-40
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• 1989

본 연구에서는 유화연료 액적의 연소시에 나타나는 일반적인 연소특성과 이에 미치는 압력의 영향에 대하여 실험적인 방법으로 연구를 수행하였다. 고압용기내에서 유화연료의 단일 액적을 연소시키면서 그 연소과정을 고속으로 촬영하여 분석하는 한편, 연소과정중의 액적 내부의 온도변화를 측정하였다. 고압 용기내의 압력은 대기압으로부터 10atm까지, 연료에 대한 물의 혼합비는 체적비로 0-20%까지 변화시키면서, 유화연료 액적의 연소특성에 미치는 물의 함량과 압력변화의 영향을 분석하였다.

• Journal of Energy Engineering
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• v.11 no.1
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• pp.74-80
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• 2002

In this study, a numerical method for fuel droplet evaporation in cylinder of S.I. engine is presented. This study was newly defined non-dimensional critical droplet lifetime and modeled heating and evaporation processes of fuel droplet during intake and compression stroke of gasoline engine. The simulation results show that simultaneous increase of gas temperature and pressure in compression stroke seems to have compensative effect on droplet gasification rate. The environment variations in cylinder have little effect on the fuel droplet gasification process. The droplet size for full evaporation at the end of compression stroke can be estimated using this program.

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.1
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• pp.47-54
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• 2002

This paper presents the results of an experimental investigation on the combustion of single droplets and 1-D droplet arrays of jet A-1 fuel droplets in atmospheric pressure. Experimental results indicate that burning rate constants$({\kappa}_c)$ of jet A-1 fuel droplets were independent of initial droplet size as $0.915{mm}^2$/sec. It was acquired a general relationship expressing the variation of $d^2$ with time for droplet burning For 1-D droplet arrays $(l/d_o$=1.208{\sim}2.922)$/TEX>, the burning rate constant ${\kappa}_c$ decreased with decreasing droplet spacing $l/d_o$ and, The effect on combustion rate constant ${\kappa}_c$ was stronger to second fuel droplet than third fuel droplet with uniform droplet distance

• Journal of Energy Engineering
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• v.10 no.2
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• pp.153-160
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• 2001

본 연구에서는 고온 분위기 온도 및 대기압 하에서 액적의 급속가열과 연소가 가능한 고온 연소로 장치와 고속도 비디오 카메라를 이용하여 다조성 단일 액적 연소에 대해 고찰하였다. 그 결과 저비점 성분을 혼합한 경유의 액적은 기본적으로 입경의 2승 법칙에 의해서 감소되었으며, 그 과정에서 입경이 일시적으로 급속히 감소하는 현상이 보여짐과 더불어 연소기간도 단축되었다. 즉, 저비점 성분을 혼합한 경유의 액적은 미세폭발 현상에 의해 기존 디젤 연료에 비해 더 빨리 증발되고 연소가 되었다. 또한, 순수 파라핀계 및 함산소계 연료의 화염은 전체 연소기간동안 기존 경유의 화염에 비해 푸른색을 띠고 있어, 매연이 없는 연소를 입증해 주었다.

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.3
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• pp.71-78
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• 2001

This paper presents the results of an experimental investigation on the combustion of single droplets arrays of Ethyl alcohol and kerosene fuel droplets in atmospheric pressure. The initial droplet diameters, d$_{0}$, were nominally 1.3~1.8mm, and inter-droplet separation distance l(l/do=1.31~2.60). experimental results indicate that burning rate constants(K) of ethyl alcohol and kerosene droplets were independent of initial droplet size as 0.0083, 0.0095 $\textrm{cm}^2$/sec. For 1-D droplet array's kerosene fuel droplet, burning rate constants(K) decreases with decreasing normalized inter-droplet distance. Normalized inter-droplet distance has stronger effect on 2nd fuel droplet than 3rd fuel droplet. When normalized inter-droplet distance is larger than 2.60, the effect of droplet spacing on droplet life is very small.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.53-57
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• 2007

고속회전의 원심력으로 연료를 공급하고 액체연료의 미립화를 초래하는 회전연료분무장치에 대한 분무특성 시험연구를 수행하였다. 특정한 공간상에 존재하는 액적의 특성을 이해하고자 고속회전 연료분사시스템을 설계 제작하였다. 시험장치는 고속으로 회전하는 Spindle, 회전연료노즐, 가압식 물탱크, 아크릴 케이스로 구성하였다. 액적의 크기와 속도를 측정하기 위해 PDPA(Phase Doppler Particle Analyzer)시스템을 사용하였고, ND-Yag Laser를 사용하여 분무를 가시화 하였다. 시험결과 고속회전 연료분사시스템의 분무특성을 확인할 수 있었고, 회전속도는 액적 크기, 속도, 분무각 및 분무패턴 등의 분무특성에 주요한 영향을 미치는 것으로 확인되었다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.6
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• pp.389-395
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• 2017

This study was performed to provide the information of the soot formation behavior of octane single fuel droplet under the identical combustion conditions. To achieve this, this experimental study provide the results of the soot formation characteristics of octane droplet in accordance with different initial droplet diameter($d_0$), at the same time, experiment was conducted under the same combustion conditions which are 1.0atm of ambient pressure($P_{amb}$), 21% of oxygen concentration($O_2$) and 79% of nitrogen concentration($N_2$). Visualization of octane droplet combustion was performed by visualization system with high speed camera. The results of maximum soot volume fraction($f_{vmax}$) was almost the same under the equivalent ambient conditions regardless of initial droplet diameter. Furthermore, maximum soot volume fraction was showed the higher value in the measuring direction between $135^{\circ}$ and $315^{\circ}$ since the soot-tail is generated during two opposing igniters movement process.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2000.04a
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• pp.2-2
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• 2000

액체연료를 사용하는 엔진의 인젝터에 대한 연구는 연소효율에 중대한 영향을 미치는 분무 액적의 크기 및 분포 특성 연구에 초점을 두어왔다. 그러나 액체 로켓 엔진은 고온, 고압의 연소실 내에서 액체상태의 연료 및 산화제 액적이 매우 빠르게 기화되기 때문에, 미립화 특성 보다는 연료와 산화제의 혼합특성이 연소효율을 결정하는 변수로 작용하게 된다. 또한 분사된 액체 추진제는 미립화 단계 이전에 기화되어 초기 화염을 형성하므로, 분사 직후의 연료/산화제의 혼합과정을 이해하는 것은 상당히 중요하다.

• Journal of Energy Engineering
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• v.8 no.2
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• pp.309-316
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• 1999

A numerical study for the turbulent reacting flow in an orimulsion gasifier has been carried out to analyze the characteristics of chemical reaction by orimulsion droplets. In this study, our interest has been focused on the effect of oxidizer to orimulsion ratio, which is one of the key parameters of gasification operation, as well as on the distribution of chemical species. In addition, we have conducted numerical calculations to understand the effect of droplet size, spray angle and injection velocity of fuel so as to acquire the basic information on the operating range of orimulsion gasifier. The result of numerical calculations showed that the gas composition of CO and H$_2$concentrations was the highest when the oxidizer to orimulsion ratio was about 0.88 and the reactivity of orimulsion increased as the droplet size reduced with proper spray angle. Also, we have carried out the analysis on the orimulsion gasification in the 100 ton/day-scale gasifier based upon the prior study in order to obtain the basic data for the proper operating condition using orimulsion feed.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.1
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• pp.1-8
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• 2013

The water-in-fuel droplets were applied to investigate the effect of mixing ratio between water and decane, ambient temperature, droplet size and spacing between droplets on ignition and micro-explosion in a heated chamber with high temperature. The ignition temperature of droplet was found lower as the droplet size was increased and the contents of water was decreased. The life time of droplet, however, decreases as the contents of water increases due to the micro-explosion. The occurrence of micro-explosion also increases as the size of droplets and the ambient temperature increase. The flame spread speed gets faster as the contents of water and the number of suspender decreases.