• Title/Summary/Keyword: Blade Length Angle

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Effect of Pitch Angle and Blade Length on an Axial Flow Fan Performance (피치각과 날개 길이에 따른 축류팬의 성능)

  • Jeon, Sung-Taek;Cho, Jin-Pyo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.1
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    • pp.43-48
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    • 2013
  • In this study, the performance of an impeller according to blade length and pitch angle was studied experimentally by building a variable pitch impeller while changing blade length to review the effect of blade length and pitch angle on a fan's performance. The pitch angle was changed in six steps from $20^{\circ}{\sim}45^{\circ}$ at intervals of $5^{\circ}$ while the blade lengths were changed to 90 mm, 100 mm, 110 mm and 120 mm with an identical airfoil shape while carrying out the experiment. The results are summarized as follows: The air flow per static pressure of axial fans increased linearly with increase of pitch angle, but the high static pressure showed a decrease at a pitch angle of $35^{\circ}$. The shaft power increased proportionally to the pitch angle at all blade lengths; the larger the pitch angle, the larger the measured increase of shaft power. This is because the drag at the fan's front increases with the pitch angle. In the axial fans considered in this research, the flow and increase of static pressure amount increased up to a pitch angle of $30^{\circ}$ but decreased rapidly above $35^{\circ}$.

CFD Analysis of Submersible Slurry Pump with Two Blades (2엽 수중 슬러리 펌프 임펠러 전산해석)

  • Yun, Jeong-Eui
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.3
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    • pp.263-268
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    • 2011
  • We aimed to develop a non-clogging submersible slurry pump with two blades to replace the conventional vortex pump. To do this, we simulated the effect of parameters such as the blade angle $\beta$ and the blade-length angle $\alpha$ on pump efficiency. We used the commercial codes ANSYS CFX and BladeGen. The results showed that the best blade shape was obtained for $\beta$ = $30^{\circ}$ and that the pump efficiency was proportional to $\alpha$ in the simulated range.

Effect of pitch angle and blade length on an axial flow fan performance (피치각과 날개 길이 변화에 따른 축류팬의 성능 및 소음 특성에 관한 실험적 연구)

  • Jeon, Sung-Taek;Cho, Jin-Pyo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.7
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    • pp.3170-3176
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    • 2013
  • In this study, the performance of an impeller according to blade length and pitch angle was studied experimentally by building a variable pitch impeller while changing blade length to review the effect of blade length and pitch angle on a fan's performance and sound characteristics. The pitch angle was changed in six steps from $20^{\circ}{\sim}45^{\circ}$ at intervals of $5^{\circ}$ while the blade lengths were changed 80 mm, 90 mm, 100 mm, 110 mm and 120 mm with an identical airfoil shape while carrying out the experiment.

A Study on Design of Wind Turbine Blade and Aerodynamic Analysis (수평축 풍력터빈 블레이드의 공력해석 및 설계에 관한 연구)

  • Kim, J.H.;Kim, B.S.;Yoon, S.H.;Lee, Y.H.
    • 유체기계공업학회:학술대회논문집
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    • 2003.12a
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    • pp.631-638
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    • 2003
  • The wind turbine blade is the equipment converted wind into electric energy. The effect of the blade has influence of the output power and efficiency of wind turbine. The design of blade is considered of lift-to-drag ratio, structure, a condition of process of manufacture and stable maximum lift coefficient, etc. This study is used the simplified method for design of the aerodynamic blade and aerodynamic analysis used blade element method. This process is programed by delphi-language. The program has any input values such as tip speed ratio, blade length, hub length, a section of shape and max lift-to-drag ratio. The program displays chord length and twist angle by input value and analyzes performance of the blade.

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Quantitative Analysis of Factors Affecting Cobalt Alloy Clip Artifacts in Computed Tomography

  • Sim, Sook Young;Choi, Chi Hoon
    • Journal of Korean Neurosurgical Society
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    • v.56 no.5
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    • pp.400-404
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    • 2014
  • Objective : Clip artifacts limit the visualization of intracranial structures in CT scans from patients after aneurysmal clipping with cobalt alloy clips. This study is to analyze the parameters influencing the degree of clip artifacts. Methods : Postoperative CT scans of 60 patients with straight cobalt alloy-clipped aneurysms were analyzed for the maximal diameter of white artifacts and the angle and number of streak artifacts in axial images, and the maximal diameter of artifacts in three-dimensional (3-D) volume-rendered images. The correlation coefficient (CC) was determined between each clip artifact type and the clip blade length and clip orientation to the CT scan (angle a, lateral clip inclination in axial images; angle b, clip gradient to scan plane in lateral scout images). Results : Angle b correlated negatively with white artifacts (r=-0.589, p<0.001) and positively with the angle (r=0.636, p<0.001) and number (r=0.505, p<0.001) of streak artifacts. Artifacts in 3-D images correlated with clip blade length (r=0.454, p=0.004). Multiple linear regression analysis revealed that angle b was the major parameter influencing white artifacts and the angle and number of streak artifacts in axial images (p<0.001), whereas clip blade length was a major factor in 3-D images (p=0.034). Conclusion : Use of a clip orientation perpendicular to the scan gantry angle decreased the amount of white artifacts and allowed better visualization of the clip site.

Investigation of Local Flow Parameters Caused by Flow Acceleration Corrosion Downstream of an Orifice in a Piping System (배관계 오리피스 하류에서 유동가속부식으로 인한 국소 유동 파라미터에 대한 조사)

  • Kim, Kyung-Hoon;Cho, Yun-Su;Kim, Hyung-Joon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.7
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    • pp.377-385
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    • 2013
  • In this study, the performance of an impeller according to blade length and pitch angle was studied experimentally by building a variable pitch impeller while changing blade length to review the effect of blade length and pitch angle on a fan's performance. The pitch angle was changed in six steps from $20^{\circ}{\sim}45^{\circ}$ at intervals of $5^{\circ}$ while the blade lengths were changed to 90 mm, 100 mm, 110 mm and 120 mm with an identical airfoil shape while carrying out the experiment. The results are summarized as follows : The air flow per static pressure of axial fans increased linearly with increase of pitch angle, but the high static pressure showed a decrease at a pitch angle of $35^{\circ}$. The shaft power increased proportionally to the pitch angle at all blade lengths; the larger the pitch angle, the larger the measured increase of shaft power. This is because the drag at the fan's front increases with the pitch angle. In the axial fans considered in this research, the flow and incre.

Stability Analysis of a Wind Turbine Blade Considering Wind Force and Variation of Pitch Angle (풍 하중과 Pitch각 변화에 따른 풍력 터빈 블레이드의 안정성 해석)

  • Kwon, Seung Min;Kang, Moon Jeong;Yoo, Hong Hee
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.12
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    • pp.1164-1171
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    • 2012
  • Recently, researches related to the green energy generation systems have increased significantly. Among them wind turbines are the most spread practical green energy generation systems. In order to enhance the power generation capacity of the wind turbine blade, the length of wind turbine blade has increased. It might cause undesirable excessive dynamic loads. Therefore dynamic characteristics of a wind turbine blade system should be identified for a safe design of the system. In this study, the equations of motion of a wind turbine blade system undergoing gravitational force are derived considering wind force and pitch angle. Effects of wind speed, variation of pitch angle of the wind turbine blade, rotating speed, and the blade length on its stability characteristics are investigated.

Development of Submersible Axial Pump for Wastewater (폐수 처리용 수중 축류 펌프 개발)

  • Yun, Jeong-Eui
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.2
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    • pp.149-154
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    • 2013
  • This study was performed to develop a high efficiency submersible axial pump for concentration wastewater treatment. To do this, we simulated the effect of some parameters such as the axial twist angle of a blade(${\beta}$), the radial twist angle of a blade(${\alpha}$) and the length of a blade (l) on pump efficiency using commercial code, ANSYS CFX and BladeGen. The results showed that the axial twist angle of a blade(${\beta}$) was the most sensible parameter on the pump efficiency. And the pump efficiency had a maximum at ${\beta}=20^{\circ}$, ${\alpha}=110^{\circ}$ and l=240 mm.

A Study on Aerodynamic Analysis and Design of Wind Turbine Blade (풍력터빈용 날개 설계 및 공력해석에 관한 연구)

  • 김정환;이영호;최민선
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.5
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    • pp.847-852
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    • 2004
  • The wind turbine blade is the equipment converted wind into electric energy. The effect of the blade has influence of the output power and efficiency of wind turbine. The design of blade is considered of lift-to-drag ratio. structure. a condition of process of manufacture and stable maximum lift coefficient, etc. This study is used the simplified method for design of the aerodynamic blade and aerodynamic analysis used blade element method This Process is programed by delphi-language. The Program has any input values such as tip speed ratio blade length. hub length. a section of shape and max lift-to-drag ratio. The Program displays chord length and twist angle by input value and analyzes performance of the blade.

Performance Characteristics according to the Outlet Impeller Blade Shape of a Centrifugal Blower (원심블로어 임펠러 토출 날개 형상에 따른 성능특성)

  • Lee, Jong-Sung;Jeon, Hyun-Jun;Jang, Choon-Man
    • The KSFM Journal of Fluid Machinery
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    • v.16 no.6
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    • pp.12-18
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    • 2013
  • This paper presents the performance characteristics of a centrifugal blower using the design parameters of an impeller blade. Two design variables, the bending length from the blade trailing edge and bending angles of an impeller blade, are introduced to analyze the effects on the blower performance. Three-dimensional Navier-Stokes equations with shear stress transport turbulence model are introduced to analyze the performance and internal flow of the blower. Relatively good agreement between experimental measurements and numerical simulation at the design flow condition is obtained. Throughout present study, it is known that pressure increases as the bending length from the trailing edge and bending angle increase while efficiency decreases. But efficiency is decreased. Detailed flow field inside the centrifugal blower is also analyzed and compared.