• Title/Summary/Keyword: Nozzle Pressure

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Study on the Optimal Design of the Nozzle Shape of the 700 bar Hydrogen Refueling Nozzle for Hydrogen Electric Vehicles (수소전기차용 700 bar 수소충전노즐의 노즐형상을 고려한 최적설계에 관한 연구)

  • Baek, Jin-Uk;Gwak, Gi-Myung;Kim, Nam-Yong;Cho, Yong-Min;Lyu, Sung-Ki
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.21 no.7
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    • pp.28-33
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    • 2022
  • In this study, we analyze the flow characteristics according to the internal shape of a 700bar hydrogen charging gun for hydrogen electric vehicles. When charging hydrogen, it receives a high-pressure charging pressure. At this time, we analyze the flow characteristics according to the shape of the nozzle and find the shape of the nozzle that minimizes energy loss. Ultimately, the optimal design of the nozzle was obtained by comparing the pressure difference between the inlet pressure and outlet pressure under a fixed mass flow condition.

The Effect of Viscosity on the Spray Characteristics of Pressure Swirl Atomizer (스월분무특성에 미치는 점성의 영향)

  • Yoon, S.J.;Cho, D.J.
    • Journal of ILASS-Korea
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    • v.4 no.4
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    • pp.24-29
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    • 1999
  • In the pressure swirl atomizer, the liquid is injected through tangential passages into a swirl chamber, from which it emerges with both tangential and axial velocity components to form a thin conical sheet at the nozzle exit. This sheet rapidly attenuates, finally disintegrating into ligaments and then drops. The purpose of this study is to measure the spray characteristics according to variation of viscosity of the spray produced by the pressure swirl atomizer. The nozzle tested here were especially designed for this investigation. The discharge coefficient is determined by measuring the volume flow rate with a flow meter and the cone angle of the liquid sheets issuing from the nozzle is obtained from series of photographs of the sheet for various liquid viscosity and injection pressure. And mean drop size is measured by image processing method. It is found that the geometrical characteristics of the nozzle and the variation of viscosity were the influential parameters to determine the spray characteristics such as the cone angle, discharge coefficients and SMD.

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Conjugate Heat Transfer Analysis of High Pressure Turbine with Secondary Flow Path and Thermal Barrier Coating (2차유로 및 열차폐 코팅을 고려한 고압터빈의 열유동 복합해석)

  • Kang, Young-Seok;Rhee, Dong Ho;Cha, Bong Jun
    • The KSFM Journal of Fluid Machinery
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    • v.18 no.6
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    • pp.37-44
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    • 2015
  • Conjugate heat analysis on a high pressure turbine stage including secondary flow paths has been carried out. The secondary flow paths were designed to be located in front of the nozzle and between the nozzle and rotor domains. Thermal boundary conditions such as empirical based temperature or heat transfer coefficient were specified at nozzle and rotor solid domains. To create heat transfer interface between the nozzle solid domain and the rotor fluid domain, frozen rotor with automatic pitch control was used assuming that there is little temperature variation along the circumferential direction at the nozzle solid and rotor fluid domain interface. The simulation results showed that secondary flow injected from the secondary flow path not only prevents main flow from penetrating into the secondary flow path, but also effectively cools down the nozzle and rotor surfaces. Also thermal barrier coating with different thickness was numerically implemented on the nozzle surface. The thermal barrier coating further reduces temperature gradient over the entire nozzle surface as well as the overall temperature level.

Performance Characteristics of Air Driven Ejector According to the Position Changes and the Shape of Driving Nozzle (공기구동 이젝터의 노즐 형상과 위치 변화에 따른 성능 특성)

  • Ji, Myoung-Kuk;Kim, Pil-Hwan;Park, Ki-Tae;Utomo, Tony;Chung, Han-Shik;Jeong, Hyo-Min
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.4
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    • pp.550-556
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    • 2008
  • The aim of this research is to analyze the influence of motive pressure, driving nozzle position and nozzle throat ratio on the performance of ejector. The experiment was conducted in the variation of motive pressure of 0.196, 0.294, 0.392 and 0.490MPa respectively. The position of driving nozzle was varied in difference locations according to mixing tube diameter(0.5d, 1d, 2d, 3d, 4.15d, 5d and 6d). The experimental results show when the nozzle outlet is located at 3d, the flow characteristics change abruptly. It is shown that the suction flow rate and pressure lift ratio of ejector is influenced by the driving nozzle position. At nozzle position location of the Id of mixing tube diameter the performance of ejector gives the best performance.

A Study on the Wide Reach Nozzle of Sprayer (III) (휴반용 분무기의 Nozzle에 관한 연구(III))

  • 원장우
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.15 no.4
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    • pp.3147-3152
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    • 1973
  • The factors to influence the travelling distance of sprayed particles for the medium range nozzle may by the groove depth of swirl plate, the cap slope, the diameter of cap hole, and pressure. 1. This study was conducted to examine Interaction effects among four factors to the travelling distance. The results of this study are summarized as followa; a) Interaction effects among four factors the groove depth(G), cap slope(C), diameter of cap hole(D), and pressure (P), were significant to influence the travelling distance except for $G{\times}P,\;C{\times}D{\times}P\;and\;G{\times}C{\times}D{\times}P$. b) Interaction effects with the pressure were very smaller than interaction effects among the other factors. c) Effect of change of the groove depth of swirl plate on the travelling distance of sprayed particles was generally a linear, the increasing rate of the change was about 0.345, which was very significant. d) Effect of change of cap slope on the travelling distance was generally a linear or a dull quadratic, the increasing rate was very small. e) Main effect of change of cap slope in the medium range nozzle was very smaller than that of the close range nozzle on the travelling distance, which was estimated by the changing of turning radius of flowing course in nozzle. f) Interaction effect between two factors in the medium range nozzle was more significant than that of the close range nozzle on the travelling distance.

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An Evaluation on Rupture Behavior of Nozzle Closure in Multi-Nozzle System (멀티노즐시스템의 노즐마개 파열 거동 분석)

  • Ro, Young-Hee
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.42 no.9
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    • pp.745-751
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    • 2014
  • For the multi-nozzle propulsion, the rupture pressure of nozzle closure has an effect on the initial strain rate of ignition. Moreover, the deviation of rupture pressure for each nozzle closure leads to side forces which can disturb the attitude control of rocket. When designed, it should be considered whether nozzle closures are ruptured equally and exactly in the intented pressure. In this paper, the rupture behavior is analyzed by analytical and experimental methods for plate and "+" notched nozzle closures. The rupture pressure and deviation for operating temperature, whether notched or not and notched directions are analyzed. This paper provides a comparison between rupture pressure prediction of finite elements method which tool is Abaqus/Explicit and results of the rupture test. Jonson-Cook shear failure model which corresponds to the damage initiation criterion were used in this simulation.

Driving Characteristics of a 1 Tube 2 Chamber Bent Silkworm Type Dyeing Machine (1 튜브 2 챔버 Bent Silkworm형 염색기의 구동특성)

  • 이춘길;성우경;이광수
    • Textile Coloration and Finishing
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    • v.11 no.2
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    • pp.64-74
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    • 1999
  • The driving characteristics of the 1 tube 2 chamber bent silkworm type dyeing machine are reported. This dyeing machine is a newly developed energy saving machine. In this study, the driving characteristics of the 1 tube 2 chamber bent silkworm type dyeing machine are examined. Specially the relationship between main body pressure and the electric current of the blower motor, the relationship between main body pressure and the air pressure of the blower nozzle, the effect of the air pressure of the blower on the running speed of the fabric, and the effect of main body temperature were discussed experimentally. Through the experimental data, the following results were obtained. 1. Blower motor electric current and blower nozzle air pressure increased as main body pressure increased due to the temperature increase of the main body. 2. The running speed of the fabric increased as blower nozzle air pressure increased. The difference in running speed between winch reel driving and no winch reel driving at a blower frequency of 60Hz was higher than that of 70Hz. 3. The electric current of the blower rioter and blower nozzle air pressure increased rapidly at the initial state. As the experimental time passed, the main body pressure increased slowly. as the main body temperature increased.

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A Study on Prediction of On-line Type Pulse Air Jet Bag Filter Effective Pulsing Distance (연속탈진형 충격기류식 여과집진장치의 여과포 유효탈진거리 예측)

  • Jeong-Sam Son;Jeong-Min Suh;Jeong-Ho Park
    • Journal of Environmental Science International
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    • v.32 no.8
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    • pp.555-561
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    • 2023
  • A study is to predict the effective pulsing distance following to the pulsing pressure, nozzle diameter, filtration velocity using numercial analysis techniques and use it as an efficient operation condition and economic data for on-line type pulse air jet bag filter. Filtration area 6 m2 condition, calculate filter resistance coefficient for simulation through the primary experiments using coke dust. For CFD simulation, analysis pulsing characteristics about nozzle diameter, filtration velocity and pulsing pressure. The maximum pulsing length of on-line type pulse air jet bag filter, in 10mm nozzle, filtration velocity 1.5m/min and pulsing pressure 5 bar conditions, is 2,285 mm, maximum length is 76.2% of the total filter bag, which is sufficient to pulsing. In 12mm nozzle, pulsing pressure 5 bar and filtration area 1.22 m2 conditions, the maximum pulsing length of on-line type pulse air jet bag filter is 1,744~2,952 mm, and the maximum length is 2,952 mm indicates pulsing air can be reached to the bottom of filter bag. When the nozzle diameter is increased 8mm to 10mm, maximum pulsing length is extended 40~47%, and increased 10mm to 12 mm, maximum pulsing length is extended 10~17%. For effective pulsing, over the 5bar of pulsing pressure and larger than 10 mm of nozzle diameter are required.

A Study on Spray Characteristics of Water Mist Nozzle with Mid-low Pressure for Fire Suppression (화재용 중저압 물분무 노즐의 분무특성에 관한 연구)

  • 김성찬;유홍선;박현태;방기영
    • Journal of the Korean Society of Safety
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    • v.18 no.1
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    • pp.28-32
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    • 2003
  • The present study investigates the spray characteristics of water mist nozzle with mid-low pressure for fire suppression. The examined nozzle types are swirl and spiral nozzle. The result shows that K factor of water mist nozzle is much smaller than those of general sprinkler. Spray angle of spiral nozzle is largest and more than $150^{\circ}$. SMD(Sauter Mean Diameter) of water mist nozzles is ranged between 100 and 200$\mu\textrm{m}$through measuring by image processing method. The spray pattern of spiral nozzle represent that water flux of first stream is 2 times larger than that of second stream. This study will contribute better understandings of the water-mist spray characteristics and useful daia for developing the water-mist nozzles.

A Study on the High-Efficiency Atomisation Molten Materials (PART 2 : A Study on the Mechanism of Liquid Supplying and Film Formation by Applying the Ejector Principle) (Atomize법에 의한 용융소재의 고효율 미세화에 관한 연구(제2보 : 이젝터의 원리를 이용한 액체노즐의 액체공급 및 액막생성 기구와 특성))

  • Oh, J.G.;Cho, I.Y.
    • Journal of ILASS-Korea
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    • v.3 no.2
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    • pp.14-23
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    • 1998
  • The negative pressure as much as 10's mmHg is demanded at nozzle inside, in case of atomizing the large density molten materials. by conventional air jet nozzle. In this study, suction type fluid nozzle is designed by applying the ejector principle in order to clarify the air flow of nozzle inside, mechanism of liquid suction and liquid film formation. The results of this experimental study areas follows. Suction force of liquid is magnified by using liquid nozzle, and it is able to supply the liquid stable. Negative pressure at nozzle inside is varied by throttle angle of liquid nozzle, position and outer diameter of air jet nozzle, and have a influence on liquid suction quantity and liquid film formation.

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