• Title/Summary/Keyword: 연료 액적

Search Result 178, Processing Time 0.023 seconds

Study of Behavior Characteristics of Emulsified Fuels with Evaporative Field (증발장에서 에멀젼연료의 거동특성에 관한 연구)

  • Yeom, Jeong Kuk;Yoon, Jeong Hwan
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.39 no.3
    • /
    • pp.237-243
    • /
    • 2015
  • In this study, the effects of the mixing ratio of emulsified fuel on the droplet evaporation and spray behavior characteristics were analyzed. A surfactant comprising span 80 and tween 80 mixed at a 9:1 ratio was used for the emulsified fuel. The fuel and surfactant were mixed at a ratio of 3:1 for the emulsified fuel. In addition, considering the mixing ratio of the surfactant, the mixing ratio of $H_2O_2$ in the emulsified fuel was set as EF (emulsified fuel)0, EF2, EF12, EF22, EF32, and EF42. To observe the evaporation characteristics, droplets of the emulsified fuel were dropped on a heating plate and observed using scattered light and a Schlieren system. In addition, to analyze the effect of the $H_2O_2$ mixing ratio, the behavior characteristics of the evaporative free spray were investigated in the mixing ratio range of EF0 to EF22 using a constant volume chamber with heaters. Consequentially, it was found that in the case of EF22, the free spray development of the emulsified fuel was faster than that of EF0 (diesel only) because of the promotion of the evaporation due to the phase change in the peroxide contained in the emulsion fuel.

The Atomization Mechanism and Spray Characteristics of Drum Type Rotary Atomizer (드럼형 회전연료노즐의 미립화 기구 및 분무특성 연구)

  • Lee, Dong-Hun;Choi, Hyun-Kyung;Choi, Seong-Man;You, Gyung-Won;Huh, Hwan-Il
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.12 no.2
    • /
    • pp.57-65
    • /
    • 2008
  • The atomization phenomena and spray characteristics of drum type rotary atomizer using centrifugal force from high rotational speed of gas turbine engine shaft were studied through rotary atomizer modeling analysis and experimental method. A test rig for rotary atomization that has range of $5,000{\sim}40,000\;rpm$ was used to make similarity for high speed rotating shaft. Spray visualization methodology and Phase Doppler Anemometry were also used to investigate the atomization mechanism and spray characteristics. We found that the rotating fuel spray has unique breakup process and we have to make breakup point earlier through increasing rotating speed to improve atomization performance.

Numerical Study on the Evaporation Characteristics of Biocrude-oil Produced by Fast Pyrolysis (급속열분해를 통하여 생산된 바이오오일 액적의 증발 특성에 관한 수치해석적 연구)

  • Choi, Sang Kyu;Choi, Yeon Seok;Kim, Seock Joon;Han, So Young
    • Applied Chemistry for Engineering
    • /
    • v.27 no.6
    • /
    • pp.646-652
    • /
    • 2016
  • Biomass is regarded as one of the promising energy sources to deal with the depletion of fossil fuels and the global warming issue. Biocrude-oil can be produced through the fast pyrolysis of biomass feedstocks such as wood, crops, agricultural and forestry residues. It has significantly higher viscosity than that of conventional petroleum fuel and contains solid residues, which can lower the spray and atomization characteristics when applied to the burner. In addition, biocrude-oil consists of hundreds of chemical species derived from cellulose, hemicellulose and lignin, and evaporation characteristics of the biocrude-oil droplet are distinct from the conventional fuels. In the present study, a numerical study was performed to investigate the evaporation characteristics of biocrude-oil droplet using a simplified composition of the model biocrude-oil which consists of acetic acid, levoglucosan, phenol, and water. The evaporation characteristics of droplets were compared at various surrounding air temperatures, initial droplet diameters, and ethanol mixing ratios. The evaporation time becomes shorter with increasing air temperature, and it is much sensitive to the air temperature particularly in low temperature ranges. It was also found that the biocrude-oil droplet evaporates faster in cases of the smaller initial droplet diameter and larger ethanol mixing ratio.

Visualization of Supercritical Mixed Hydrocarbon-Fuel Droplet (혼합 탄화수소계 초임계 상태 연료의 액적 거동 가시화)

  • Song, Juyeon;Song, Wooseok;Koo, Jaye
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.48 no.9
    • /
    • pp.711-716
    • /
    • 2020
  • Injection visualization of heated mixed simulant droplets based on hydrocarbon fuel was performed under supercritical state environment. Mixed simulant consisted of Decane and Methylcyclohexane with different critical pressure and critical temperature. Flows injected into the supercritical state environment created droplet by Rayleigh breakup mechanism, and the Oh number and Re number were determined to confirm the breakup area. The temperature of the mixed simulant varied from Tr=0.49 to Tr=1.34. The flow rate was maintained at 0.7 to 0.8 g/s. Droplet became shorter in breakup length as heated and into a lumped form. Second droplet was formed and when Tr=1.34, the phase was not visible in the supercritical state with local unsteady flow.

An experimental study on the evaporation of paraffin family fuel droplet under high temperature and high pressure (고온 고압기류중을 비행하는 파라핀계 연료액적의 증발에 관한 연구)

  • ;川口修
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.15 no.6
    • /
    • pp.2125-2131
    • /
    • 1991
  • Evaporation rate constant, obtained by in this experimental study, of freely falling liquid fuel droplet on the condition of hot and pressurized environment are converted to critical evaporation constant according to Eq. of Ranz and Marshall. Critical evaporation constant, on constant environment pressuire, actively increase almost linearly with environment temperature increasing, but, on constant temperature, increases more or less with pressure increasing. Multycomponent droplet mixed with the fine fuel having a different of boiling point evaporate in order to boiling point, and each evaporation rate constant of mixed fuel equal to each fuel.

A Numerical Study of Combustion Characteristics of Hydrocarbon Fuel Droplet (탄화수소 연료 액적의 연소 특성에 관한 수치해석)

  • Lee, Bong-Su;Lee, Kyung-Jae;Kim, Jong-Hyun;Koo, Ja-Ye
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.27 no.11
    • /
    • pp.1595-1603
    • /
    • 2003
  • Droplet combustion at high ambient pressures is studied numerically by formulating one dimensional combustion model in the mixture of n-heptane fuel and air. The ambient pressure is supercritical conditions. The modified Soave-Redlich-Kwong state equation is used in the evaluation of thermophysical properties to account for the real gas effect on fluid p-v-T properties in high pressure conditions. Non-ideal thermodynamic and transport property at near critical and supercritical conditions are also considered. Several parametric studies are performed by changing ambient pressure and initial droplet diameter. Droplet lifetime decreased with increasing pressure. Surface temperature increased with increasing pressure. Ignition time increased with increasing initial droplet diameter. Temporal or spatial distribution of mass fraction, mass diffusivity, Lewis number, thermal conductivity, and specific heat were presented.

Analysis for Spray Flow Using PSIC Model in Combustion Chamber of Liquid Rocket Engine (PSIC 모델을 이용한 액체로켓의 연소실내 분무유동 해석)

  • Jeong Dae-Kwon;Roh Tae-Seong
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2006.05a
    • /
    • pp.253-256
    • /
    • 2006
  • A numerical study for spray flow of fuel and oxidizer droplets in the combustion chamber has been conducted prior to the analysis of spray combustion of the liquid rocket engine. As the spray combustion model, DSF model and Euler-Lagrange scheme have been used. While the coupling effects of the droplets between gas phase and evaporated vapor have been calculated using PSIC model, SIMPLER algorithm and QUICK scheme have been used as numerical schemes. As the results, the calculations have shown velocity and temperature distribution in combustion chamber as well as mole fraction of fuel and oxidizer.

  • PDF

Study on the Combustion Characteristics of Methanol Fuel Droplet (Methanol 연료 액적의 연소 특성에 관한 연구)

  • Suh, Hyun Kyu
    • Journal of ILASS-Korea
    • /
    • v.19 no.3
    • /
    • pp.109-114
    • /
    • 2014
  • The main purpose of this study is to provide basic information of droplet burning, extinction process and flame behavior of methanol fuel and improve the ability of theoretical prediction of these phenomena. For the improved understanding of these phenomena, this paper presents the experimental results on the methanol droplet combustion conducted under various initial droplet diameters ($d_0$), ambient pressure ($P_{amb}$), and oxygen concentration ($O_2$) conditions. To achieve this, the experimental study was conducted in terms of burning rate (K) with normalized droplet diameter ($d/d_0$), flame diameter ($d_f$) and flame standoff ratio (FSR) under the assumptions that the droplet combustion can be described by both the quasi-steady behavior for the region between the droplet surface and the flame interface and the transient behavior for the region between the flame interface and ambient surrounding.

Numerical Modeling of Droplet/Wall Impingement Process (연료분무의 벽면충돌과정 해석에 대한 수치모델링)

  • Moon, Y.W.;Yu, Y.W.;Kim, Y.M.
    • Journal of ILASS-Korea
    • /
    • v.4 no.2
    • /
    • pp.10-18
    • /
    • 1999
  • The droplet/wall impingement processes in the diesel-like environment are numerically modeled. In order to evaluate the predictive capability of the droplet/wall impingement model developed in this study, computations are carried out for two ambient temperature conditions. Numerical results indicate that the present droplet/wall impingement model reasonably well predicts the basic features of the impinging spray dynamics.

  • PDF

Measurement of spray by using an image processing method (화상처리법을 이용한 분무 계측)

  • 조병옥
    • Journal of the korean Society of Automotive Engineers
    • /
    • v.16 no.6
    • /
    • pp.22-27
    • /
    • 1994
  • 여기서는 화상처리 방법에서 화상 획득 장치와 처리 장치를 간단히 소개하고, 연료분무의 액적 운동속도의 계측 방법에 대하여 논의하기로 한다. 화사처리법은 비교적 저렴한 비용으로 정밀도 높은 정보를 프로그램에 따라 다양하게 출력하는 등의 잇점이 있다. 분무 각과 분무 관통길이도 화상 획득 장치만 기계식 스틸 카메라를 이용한 것뿐이지, 그 처리 방법은 앞서 논의한 방법과 유사하다. 1. 화상처리방법. 1.1 화상획득장치. 1.2 화상처리방법. 2. 액적크기와 운동속도. 2.1 액적크기. 2.2 운동속도.

  • PDF