• 한국분무공학회지
• /
• 제3권3호
• /
• pp.42-48
• /
• 1998

This study describes the spray structure of gasoline port injectors by using phase Doppler particle analyzer(PDPA) and particle motion analysis system(PMAS). The characteristics of fuel spray such as the spray penetration, spray angle and breakup processes were obtained by PMAS and the droplet size and mean velocity were measured by PDPA system. Pintle type and two-hole type injectors were used as gasoline port fuel injectors under various injection pressures. The effect of injection pressure on the droplet mean diameter and axial mean velocity of droplet were investigated under the various injection conditions. In addition the comparison of breakup processes for the two types of injectors was also conducted. It Is shown that pintle type injector has smaller droplet size than that of two-hole type injector.

• 한국분무공학회지
• /
• 제7권3호
• /
• pp.24-30
• /
• 2002

In the analysis of the mass distribution and SMD(Sauter Mean Diameter), planar laser imaging technique is a convenient and useful one when compared to the mechanical pattemator or PDPA (Phase Doppler Particle Analyzer). But recorded signals at cameras and intensity of laser are distorted by attenuation. Using experimental datum and assumptions, we study measurement errors due to attenuation in plannar image technique.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2007년도 제29회 추계학술대회논문집
• /
• pp.359-364
• /
• 2007

APU 가스터빈엔진의 연료분무특성을 연구하였다. 지상 및 고도 작동조건에 대한 연료분무특성 실험을 수행하여 APU 엔진의 실화 가능성을 검토하였다. 분무실험은 4개의 작동조건에 대하여 수행되었으며 각 조건은 지상 무부하 및 통합부하 조건과 고도 20,000 feet 무부하 및 통합부하에 대한 실험을 수행하였다. 분무특성은 PDPA를 이용한 입자의 크기 및 속도 측정과 레이저 빔을 이용한 가시화를 수행하였다. 연구결과 20,000 feet 무부하의 경우 입자의 크기가 100 ${\mu}m$정도이며 분무속도가 10 m/s로 낮아 화염안정성을 위한 개선이 필요할 것으로 판단된다.

• 한국분무공학회지
• /
• 제20권1호
• /
• pp.35-42
• /
• 2015

This study is to investigate the spray behavior of DME-LPG blended fuels in common rail injection system for diesel engines. The visualization experiment was performed to analyze the macroscopic spray behavior of test fuels. In addition, the experiment using BOS(Background Oriented Schlieren) method is performed to compare liquid phase and gas phase. The test fuels are injected in high pressure chamber. The ambient pressure of high pressure chamber was formed by nitrogen gas. Spray tip penetration, spray cone angle and spray area were measured using high speed camera. SMD(Sauter Mean Diameter) and spray particle velocity were measured using the PDPA(Phase Doppler Particle Analyzer) system to analyze the microscopic properties of test fuels. The results of this experiment showed that spray tip penetration, spray cone angle and spray area of DME-LPG fuels are similar to those of DME fuel. When compared to results of experiment using BOS, significant differences of spray tip penetrations, spray cone angle and spray area are showed because of gas phase. The results of experiment using BOS method showed higher values. SMD of DME-LPG blended fuels is smaller than that of DME fuel. Velocity of DME-LPG blended fuels is faster than that of DME fuel.

• Journal of Mechanical Science and Technology
• /
• 제16권12호
• /
• pp.1693-1701
• /
• 2002

The intermittent spray characteristics of a multi-hole and a single-hole diesel nozzle were experimentally investigated. The hole number of the multi-hole nozzle was 5, and the hole diameter of the 5-hole and the single-hole nozzle was the same as d$\_$n/=0.32 ㎜ with the constant hole length to diameter ratio(l$\_$n//d$\_$n/=2.81). The droplet diameters of the spray, including the time-resolved droplet diameter, SMD (Sauter mean diameter) and AMD (arithmetic mean diameter) , injected intermittently from the two nozzles into the still ambient were measured by using a 2-D PDPA (phase Doppler particle analyzer). Through the time-resolved evolutions of the droplet diameter, it was found that the structure of the multi-hole and the single-hole nozzle spray consisted of the three main parts : (a) the leading edge affected by surrounding air. and composed of small droplets; (b) the central part surrounded by the leading edge and mixing flow region and scarcely affected by the resistance of air, (c) the trailing edge formed by the passage of the central part. The SMD decreases gradually with the increase in the radial distance, and the constant value is obtained at the outer region of the radial distance (normalized by hole diameter) of 7-8 and 6 for the 5-hole and single-hole nozzle, respectively. The SMD along the centerline of the spray decrease shapely with the increase in the axial distance after showing the maximum value near the nozzle tip. The SMD remains the constant value near the axial distance(normalized by hole diameter) of 150 and 180 for the 5-hole and the single-hole nozzle, respectively.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2007년도 제29회 추계학술대회논문집
• /
• pp.354-358
• /
• 2007

초소형 터보제트엔진에 적용되는 슬링거 인젝터 시스템의 분무특성을 파악하기 위한 연구를 수행 하였다. 이 연료 분사시스템은 엔진의 회전축으로부터 발생된 원심력에 의하여 연료가 연소기 내부로 공급되고, 액체연료의 미립화를 초래한다. 시험장치는 고속으로 회전하는 Spindle, 슬링거 인젝터, 가압식 물탱크, 아크릴 케이스로 구성하였다. 분무입자의 크기 및 속도를 측정하기 위해 PDPA(Phase Doppler Particle Analyzer) 시스템을 사용하였고, Nd-Yag Laser를 광원으로 사용하여 분무를 가시화 하였다. 시험결과 SMD(Sauter Mean Diameter)는 회전수, 유량, Injection Orifice 수에 큰 영향을 받는 것으로 나타났다. 이러한 실험적 연구로부터 이 시스템의 분무특성을 이해할 수 있었고, 초소형 터보제트엔진에 적합한 슬링거 인젝터의 형성을 도출할 수 있었다.

• 한국추진공학회지
• /
• 제14권5호
• /
• pp.51-56
• /
• 2010

고속회전 시험장치를 이용하여 V 형태의 회전식 연료 노즐의 오리피스 직경에 따른 분사특성을 파악하기 위한 연구를 수행하였다. 시험장치는 고속 회전장치, 연료공급장치, 아크릴 케이스로 구성하였다. 분무 오리피스의 직경과 회전속도를 변화시켜가며 분무실험을 수행하였다. 분무입자의 크기 및 속도 측정은 PDPA(Phase Doppler Particle Analyzer) 시스템을 사용하였고, Nd-Yag Laser를 이용하여 분무특성을 가시화하였다. 실험결과, 분무오리피스의 직경이 커질수록 분무입자의 크기가 작아졌으며, 분무입자 크기가 가장 작은 값을 보이는 분무오리피스의 한계 직경이 존재하였다. 오리피스의 직경이 이 한계직경 보다 클 경우 분무입자의 크기는 더 이상 감소하지 않았다. 이것은 분무 오리피스의 직경이 한계직경보다 커질 경우 오리피스 내의 액막이 균일하게 분포하지 않기 때문으로 판단된다.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2010년도 제34회 춘계학술대회논문집
• /
• pp.258-263
• /
• 2010

고속회전 시험장치를 이용하여 V 형태의 회전식 연료 노즐의 오리피스 직경에 따른 분사특성을 파악하기 위한 연구를 수행하였다. 시험장치는 고속 회전장치, 연료공급장치, 아크릴 케이스로 구성하였다. 분무 오리피스의 직경과 회전속도를 변화시켜가며 분무실험을 수행하였다. 분무입자의 크기 및 속도 측정은 PDPA(Phase Doppler Particle Analyzer) 시스템을 사용하였고, Nd-Yag Laser를 이용하여 분무특성을 가시화하였다. 실험결과, 분무오리피스의 직경이 커질수록 분무입자의 크기가 작아졌으며, 분무 오리피스의 직경이 2.6mm인 경우 최적의 분무형태를 보였다. 그러나 오리피스의 직경이 이보다 클 경우 분무입자의 크기는 더 이상 감소하지 않았다. 이것은 분무오리피스가 최적의 직경보다 커질 경우 오리피스내의 액막이 균일하게 분포하지 않기 때문으로 판단된다.

• Journal of Mechanical Science and Technology
• /
• 제17권5호
• /
• pp.766-775
• /
• 2003

The intermittent spray characteristics of a multi-hole diesel nozzle with a 2-spring nozzle holder were investigated experimentally. Without changing the total orifice exit area, the hole number of the multi-hole nozzle varied from 3 (d$\_$n/=0.42 mm) to 5 (d$\_$n/=0.32 mm). The time-resolved droplet diameters of the spray including the SMD (Saute. mean diameter) and the AMD (arithmetic mean diameter), injected intormittently from the multi-hole nozzles into still ambient ai., were measured by using a 2-D PDPA (phase Doppler particle analyze.). The 5-hole nozzle spray shows the smaller spray cone angle, the decreased SMD distributions and the small difference between the SMD and the AMD, compared with that of the 3-hole nozzle spray. From the SMD distributions with the radial distance, the spray structure can be classified into the three regions : (a) the inner region showing the high SMD distribution , (b) the mixing flow region where the shea. flow structure would be constructed : and (c) the outer region formed through the disintegration processes of the spray inner region and composed of fine droplets. Through the SMD distributions along the spray centerline, it reveals that the SMD decreases rapidly after showing the maximum value in the vicinity of the nozzle tip. The SMD remains the constant value near the Z/d$\_$n/=166 and 156.3 for the 3-hole and 5-hole nozzles, which illustrate that the disintegration processes of the 5-hole nozzle spray proceed more rapidly than that of the 3-hole nozzle spray.

• 한국분무공학회지
• /
• 제15권2호
• /
• pp.53-60
• /
• 2010

This study presents development of digital particle holographic system and its application to spray field to measure three-dimensional velocities and sizes of spray droplets. A double exposure hologram recording system with synchronization system for time control was established and digital holograms can be recorded in a short time interval. To process recorded holograms, the correlation coefficient method was used for focal plane determination of particles. To remove noises and improve the quality of holograms and reconstructed images, the Wiener filter was adopted. The two-threshold and image segmentation methods were used in binary image transformation. For particle pairing, the match probability method was adopted. The developed system was applied to spray field and three-dimensional velocities and sizes of spray droplets were measured. The measurement results of digital holographic system were compared with those made by laser instruments, PDPA(Phase Doppler Particle Analyzer), which proved the feasibility of in-line digital particle holographic system as a good measurement tool for spray droplets.