• Title/Summary/Keyword: Nozzle Angle

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Performance Analysis of an Expansion Deflection Nozzle by Nozzle Length Reduction Method (노즐 길이 단축 방안에 따른 ED 노즐의 성능 분석)

  • Joomi Lee;Junsub Choi;Hwanil Huh
    • Journal of the Korean Society of Propulsion Engineers
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    • v.26 no.5
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    • pp.11-23
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    • 2022
  • For the design of the shortened ED(Expansion Deflection) nozzle, a numerical study of ED nozzle was performed according to the length reduction methods. The first method is to reduce the extension length of the ED nozzle with 80% bell nozzle length by 10%, 20% and 30%. The second method is to shorten the extension length by increasing the nozzle throat angle. Due to the increase in the curvature of the contour as the length shortened, the decrease in the nozzle exit velocity between the ED nozzle with 80% bell nozzle length and the ED nozzle in the first method was reduced, and the thrust become similar. The ED nozzle of the second method increased the thrust by increasing the nozzle exit velocity compared to the ED nozzle with 80% bell nozzle length.

Numerical Study on an E-D Nozzle Characteristics with Various Pintle Inflection Angles (핀틀 변곡 각도에 따른 E-D 노즐 특성에 대한 전산수치해석 연구)

  • Park, Sanghyeon;Moon, Taeseok;Huh, Hwanil
    • Journal of the Korean Society of Propulsion Engineers
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    • v.22 no.6
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    • pp.19-27
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    • 2018
  • In this study, a numerical study was conducted to characterize the E-D nozzle which changes according to the nozzle pressure ratios. Three different numerical analysis models were designed by changing the pintle inflection angles. When the nozzle pressure ratio is low, the outside air flows into the E-D nozzle to form an open flow field. As the nozzle pressure ratio increases, the flow transition occurs to become the closed flow field where the recirculation region is isolated inside the nozzle. Also, the highest thrust coefficient was obtained in the analytical model with high pintle inflection angle at all nozzle pressure ratios.

A Numerical Study on Combustion Characteristics of Fuel/Oxidizer in a Solid-Particle Incinerator (고체 입자 소각로에서 연료/산화제의 연소 특성에 관한 수치해석적 연구)

  • Kim, Suho;Sohn, Chae Hoon
    • 한국연소학회:학술대회논문집
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    • 2012.11a
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    • pp.3-4
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    • 2012
  • Characteristics of the flow in the incinerator were studied in terms of the cold flow and combustion using multi-staged tangential burner. The design parameters such as deflection angle of main nozzle, and decline angle of assist nozzle habe been changed. The effects of each parameter on burning characteristics have been investigated.

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An Effect of Pressure and Temperature on Spray Characteristic (분무특성에 미치는 압력.온도의 영향)

  • Oh, Eun-Tak;Ryu, Ho-Sung;Ahn, Byoung-Kyu;Song, Kyu-Keun;Jung, Jae-Youn
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.946-951
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    • 2001
  • This experimental study is to investigate the intermittent spray characteristics of a pintle nozzle. High speed camera used in this expreiment with 9000fps. The factor, which controls the diesel spray, is the Injection pressure, ambient pressure and ambient temperature. In this paper, experiments were conducted free spray for the ambient pressure(3, 4, 5Mpa), nozzle Injection pressure(10, 14, 18MPa) and ambient temperature(293, 473K). With the higher opening pressure, the spray tip velocity and spray penetration increases while the spray angle decreases, On the other hand, With the higher ambient pressure, the spray angle increase while the spray tip penetration and spray tip velocity decrease. also, With the higher ambient temperature, the spray penetration decrease while the spray angle decrease.

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A Numerical Study on the Effect of Pitch Angle of Helical Nozzle on the Vortex Tube Performance Characteristics (헬리컬 노즐의 피치각에 따른 볼텍스 튜브의 성능특성에 관한 연구)

  • Oh, Yeong Taek;Kim, Kuisoon
    • The KSFM Journal of Fluid Machinery
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    • v.19 no.1
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    • pp.11-17
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    • 2016
  • In this paper, a numerical analysis was performed to investigate the effect of the pitch angle of a helical nozzle on the performance characteristics of a vortex tube. Three-dimensional numerical simulation has been performed with standard $k-{\varepsilon}$ turbulence model by using FLUENT 13.0. The effect of the pitch angle of helical nozzle was described in term of ${\beta}$. A CFD analysis was performed on ${\beta}=0^{\circ}$, $5^{\circ}$, $10^{\circ}$, $15^{\circ}$. In order to realize the influence of ${\beta}$ on performances of the vortex tube. Computation results were expressed by the ${\beta}-{\Delta}T_{h,c}$ graph and radial profiles of axial velocity and swirl velocity. The results showed that ${\beta}$ which improves energy separation capacity of vortex tube was $5^{\circ}$ at ${\alpha}=0.33$, 0.5 and $10^{\circ}$ at ${\alpha}=0.33$. Besides, It was confirmed that the results were closely related to axial velocity and swirl velocity.

An Experimental Study on the Drop Size of a Twin-Fluid Swirl Jet Nozzle (이유체 선회분사 노즐의 액적크기에 관한 실험적 연구)

  • Oh, J.H.;Kim, W.T.;Kang, S.J.;Rho, B.J.
    • Journal of ILASS-Korea
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    • v.1 no.1
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    • pp.21-27
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    • 1996
  • This experimental study was to investigate spray angles and drop sizes in an external mixed twin-fluid swirl jet nozzle. Twin-fluid swirl jet nozzle with swirlers designed four swirl angles such as $0^{\circ},\;22.5^{\circ},\;45^{\circ},\;64.2^{\circ}$ was employed. A PDA system was utilized for the measurement of drop size and mean velocity. Water and air were used as the working fluids in this experiment. The mass flow rate of water was fixed as 0.03 kg/min, and air flow rates were controlled to have the air/liquid mass ratio from 1.0 to 6.0. As a result, swirl angle controlled to spray angles and drop sizes. It was found that swirl angle was increased with spray angle and with decreased SMD. However, the effect of swirl angle was reduced at large air/liquid mass ratio(Mr=6.0).

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Dynamic Characteristics of Cantilever Pipe Conveying Fluid with Moving Mass Considering Nozzle Angle (노즐 경사각을 고려한 이동질량을 가진 유체이송 외팔 파이프의 동특성 해석)

  • 윤한익;손인수;김현수;조정래
    • Journal of Ocean Engineering and Technology
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    • v.16 no.6
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    • pp.18-24
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    • 2002
  • The vibrational system in this study consists of a cantilever pipe conveying fluid, the moving mass upon it, and an attached tip mass. The equation of motion is derived by using the Lagrange equation. The influences of the velocity and the velocities of fluid flow in the pipe have been studied on the dynamic behavior of a cantilever pipe using a numerical method. While the moving mass moves upon the cantilever pipe, the velocity of fluid flow and the nozzle angle increase; as a result, the tip displacement of the cantilever pipe, conveying fluid, is decreased. After the moving mass passes over the cantilever pipe, the tip displacement of the pipe is influenced by the potential energy of the cantilever pipe and the deflection of the pipe; the effect is the result of the moving mass and gravity. As the velocity of fluid flow and nozzle angle increases, the natural frequency of he system is decreased at the second mode and third mode, but it is increased at the first mode. As the moving mass increases, the natural frequency of the system is decreased at all modes.

Effects of the Bio-diesel Blending Rate on the Spray Characteristics of the Pressure Swirl Nozzle (바이오 디젤 혼합율이 압력식 스월노즐의 분무 특성에 미치는 영향)

  • Yoon, S.J.
    • Journal of ILASS-Korea
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    • v.16 no.4
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    • pp.210-214
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    • 2011
  • This paper presents the spray characteristics of the gun type burner nozzle with bio-diesel blending rate. The burner nozzle used in this experiment is a pressure swirl type nozzle. For the spray characteristics, visualization of spray was conducted to obtain the spray angle, and laser diffraction spectroscope (LDS) was used for the measurement of the droplet diameters. The results showed that the $D_{max}$, SMD and spray angle were decreased with increasing the bio-diesel blending rate and BD30 (30% bio-diesel blending rate) could be found to be the maximum blending rate for using without any modification of the gun type burner of the homesize kerosene fuel boiler.

Comparison of Spray Characteristics between Conventional and Electrostatic Pressure-Swirl Nozzles

  • Laryea, G.N.;No, S.Y.
    • Journal of ILASS-Korea
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    • v.11 no.1
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    • pp.24-29
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    • 2006
  • Spray characteristics produced by conventional and electrostatic pressure-swirl nozzles for an oil burner have been studied, using kerosine as a test liquid. The charge injection mechanism is used to design the electrostatic nozzle, where specific charge density, breakup length, spray angle and mean diameter are measured and analyzed. Three nozzles with orifice diameters of 0.256, 0.308 and 0.333mm at injection pressures of 0.7, 0.9, 1.1 and 1.3 MPa are used in the study. In case of the electrostatic nozzle, voltages ranging from -5 to -12kV are applied. Comparison of the spray characteristics is made between the conventional and electrostatic nozzles. The results showed that, the electrostatic nozzle is superior to the conventional nozzle. This is due the effect of voltage on the liquid surface tension.

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Effect of nozzle geometry on the injection characteristics and spray behavior (고압 분사 디잴 인잭터의 노즐 형상이 분사 특성 및 분무 거동에 미치는 영향)

  • Lee, C.S.;Park, S.W.;Chon, M.S.
    • Journal of ILASS-Korea
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    • v.9 no.1
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    • pp.1-7
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    • 2004
  • This paper describes the characteristics of injection rate and macroscopic behavior of fuel spray injected from common-rail type diesel injectors with different nozzle geometries. The injection rates according to the nozzle geometries were measured at different energizing duration of the injector solenoid and injection pressure by using the Bosch's injection rate meter based on the pressure variation in the tube. The spray behaviors injected from the different nozzles were visualized using the spray visualization system composed of an Ar-ion laser, an ICCD camera, and a synchronization system at various injection and ambient pressures. It is revealed that VCO nozzle has higher spray tip velocity at the early stage of injection duration and wider spray cone angle than the mini-sac nozzles. Also the spray cone angle is increased with the increase of nozzle diameter.

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