• Title, Summary, Keyword: Axial Shape

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Effects of Cutting Speed and Feed Rate on Axial Shape in Side Walls Generated by Flat End-milling Process (평엔드밀링 공정에서 절삭속도 및 이송속도가 측벽의 축방향 형상에 미치는 영향)

  • Kim, Kang
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.5
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    • pp.391-399
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    • 2017
  • This paper presents the effects of the cutting speed and feed rate on the axial shape of flat end-milled down cut side walls. Experiments were performed using the cutting speed, tool diameter, and feed per tooth as variables, and the thrust force and axial shape were measured as the experimental results. The results of this study confirmed that a smaller feed per tooth, which is proportional to the value obtained by dividing the feed rate by the cutting speed, results in a higher axial shape accuracy. In addition, the axial shape can be simplified to a form in which two straight lines having different slopes meet at a singular point. Therefore, it was concluded that the shape accuracy could easily be estimated during the operation and improved by adjusting the feed per tooth.

Bearing Capacity Estimation of Tapered Pile Using Step-wise shape (등가변형을 이용한 테이퍼 말뚝의 지지력 산정)

  • Jun, Sung-Nam;Seo, Kyoung-Bum;Lee, Jun-Hwan
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.490-495
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    • 2009
  • In this study, estimate solution of ultimate axial capacity for axial loaded pile is proposed using step-wised shape. This is verified for effective appling on realistic factor by calibration chamber tests. Estimation method of ultimate axial capacity in this study is verified by calibration chamber test. The results of ultimate axial capacity through this proposed method have sufficiently low standard derivations and COVs. Also, this is verified through test that method is similarly resulted with measured values.

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Study on the Minimization of Shape Parameters by Reverse Design of an Axial Turbine Blade (축류형 터빈 익형의 역설계에 의한 최소 형상변수에 관한 연구)

  • Cho, Soo-Yong;Oh, Koon-Sup;Yoon, Eui-Soo;Choi, Bum-Seog
    • The KSFM Journal of Fluid Machinery
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    • v.3 no.4
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    • pp.30-37
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    • 2000
  • Several reverse design methods are developed and applied to the suction or pressure surface for finding design values of blade geometry for a given axial turbine blade. Re-designed blade profiles using shape parameters are compared with measured blade data. Essential shape parameters for blade design are induced by the procedure of reverse design for best fitting. Characteristics of shape parameters are evaluated through the system design method and restriction conditions of structural stability or aerodynamic flow loss. Some of shape parameters i.e blade radius or exit blade angle etc., are classified to weakly adjustable shape parameters, otherwise strongly adjustable shape parameters which would be applied for controlling blade shape. Average deviation values between the measured data and re-designed blade using shape parameters are calculated for each design method. Comparing with the average deviation for a given blade geometry, minimum shape parameters required to design a blade geometry are obtained.

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Optimal Design for Stacking Line of Rotor Blade in a Single-Stage Transonic Axial Compressor (단단 천음속 축류압축기 동익의 Stacking Line 설계 최적화)

  • Jang Choon-Man;Abdus Samad;Kim Kwang-Yong
    • The KSFM Journal of Fluid Machinery
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    • v.9 no.3
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    • pp.7-13
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    • 2006
  • Shape optimization of a rotor blade in a single-stage transonic axial compressor has been performed using a response surface method and three-dimensional Navier-Stokes analysis. Two shape variables of the rotor blade, which are used to define a blade skew, are introduced to increase an adiabatic efficiency. Throughout the shape optimization of a rotor blade, the adiabatic efficiency is increased to about 2.2 percent compared to that of the reference shape of the stator. The increase in efficiency for the optimal shape of the rotor is due to the pressure enhancement, which is mainly caused by moving the separation position on the suction surface of rotor blade to the downstream direction.

Shape Optimization of a Stator Blade in a Single-Stage Transonic Axial Compressor (단단 천음속 축류압축기의 정익형상 최적설계)

  • Kim Kwang Yong;Jang Choon Man
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.29 no.5
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    • pp.625-632
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    • 2005
  • This paper describes the shape optimization of a stator blade in a single-stage transonic axial compressor. The blade optimization has been performed using response surface method and three-dimensional Navier-Stokes analysis. Two shape variables of the stator blade, which are used to define a stacking line, are introduced to increase an adiabatic efficiency. Data points for response evaluations have been selected by D-optimal design, and linear programming method has been used for an optimization on a response surface. Throughout the shape optimization of a stator blade, the adiabatic efficiency is increased to 5.8 percent compared to that of the reference shape of the stator. The increase of the efficiency is mainly caused by the pressure enhancement in the stator blade. Flow separation on the blade suction surface of the stator is also improved by optimizing the stator blade. It is noted that the optimization of the stator blade is also useful method to increase the adiabatic efficiency in the axial compressor as well as the optimization of a rotor blade, which is widely used now.

A Numerical Analysis of the Partial Admission Supersonic Turbine Losses for Geometic Conditions (형상 변수에 따른 부분 흡입형 초음속 터빈 손실에 관한 수치적 연구)

  • Shin Bong-Gun;Im Kang-Soo;Kim Kui-Soon;Jeong Eun-Hwan;Park Pyun-Goo
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.297-305
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    • 2006
  • In this paper, numerical analyses of the flow within turbine for geometric conditions such as nozzle shape, length of axial clearance, and chamfer angle of leading edge of blade have been performed to investigate the partial admission supersonic turbine losses. Firstly, flow's bending occurred at axial clearance is depended on nozzle shape. Next, the chamfer angle of leading edge affects the strength of shock generated at the leading edge. Finally the expansion and mixsing of the flow within axial clearance are largely depended upon the length of axial clearance. Therefore it is found that aerodynamic losses of turbine is affected by nozzle shape and chamfer angel and that partial admission losses is depended on nozzle shape and the length of axial clearance.

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Theoretical Analysis of the Slipper Hydrostatic Bearing Shape in the Swash Plate Type Axial Piston Pump (사판식 유압 피스톤 펌프의 슬리퍼 정압베어링면 형상에 관한 이론해석)

  • Cho, I.S.
    • Journal of Drive and Control
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    • v.10 no.1
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    • pp.14-20
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    • 2013
  • In the high rotational speed and pressure state, the leakage flow rate of the axial piston pump is one of the serious problems and make great reasons to decrease the volume efficiency. In this study, tribology characteristics is clarified for the hydrostatic slipper bearing in the swash plate type axial piston pump, by means of theoretical analysis for the different shape of the hydrostatic slipper bearing. It was analyzed by Mathcad software and used equal conditions at $0^{\circ}$ swash plate angle in each model. The results show that performance characteristics of the swash plate type axial piston pump are significantly influenced by the shape of the hydrostatic slipper bearing.

A Study on the Production Mechanisms of Residual Stress in Welded T-joint of Steel Pipe Member (T형 강관 용접 이음부의 잔류응력 생성기구에 관한 연구)

  • 장경호;장갑철;경장현;이은택
    • Journal of Welding and Joining
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    • v.21 no.6
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    • pp.40-45
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    • 2003
  • Steel members have advantages of resisting torsion and axial compression. In design, residual stresses at the welded joint of T-shape steel pipes are one of the most important points to be considered. In this paper, characteristics of residual stresses of welded joints are clarified by carrying out 3D non-steady heat conduction analysis and 3D thermal elastic-plastic FE-analysis. According to the results, the production mechanism of residual stresses at the welded joint of T-shape steel pipe is clarified. In this paper, circumferential stresses depended on thermal histories but axial and radial stresses were more dependent on geometrical shape than thermal histories. Residual stresses in the axial direction on the lower part of pipe member were tensile, controlled by geometrical shape. However, in case of middle part, residual stresses in all the directions were controlled by thermal histories.

An Experimental Study in Rectangular High Strength Concrete Columns under Both Axial Load and Biaxial Bending (2축 편심 축하중을 받는 직사각형 고강도 RC기둥의 거동에 대한 실험적연구)

  • 이종원;조문희;한경돈;유석형;반병열;신성우
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.209-214
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    • 2001
  • Most reinforce concrete Columns of Building structure are subjected to both axial load and biaxial bending. However, It is hard to estimate the moment capacity of biaxial bending by exact solution. Thus, columns under biaxial bending are designed by approximate methods in practice. The purpose of this study is to compare experimental result with approximate methods and exact solution by computer. Parameters of the present test are compressive strength of concrete (350, 585, 650kgf/$\textrm{cm}^2$) and shape ratio of rectangular section. Ultimately, an experimental shape factor for rectangular RC column section is obtained through the test program. The shape of load contour is dominated by this shape factor obtained experimentally. So, reasonable design of RC columns subjected to both axial compression and biaxial bending depends on load contour.

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Evaluation of Efficiency by Applying Different Optimization Method for Axial Compressor (최적화 방법에 따른 축류압축기의 효율평가)

  • Jang, Choon-Man;Abdus, Samad;Kim, Kwang-Yong
    • 유체기계공업학회:학술대회논문집
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    • pp.543-544
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    • 2006
  • Shape optimization of a transonic axial compressor rotor operating at the design flow condition has been performed using three-dimensional Navier-Stokes analysis and three different surrogate models: i.e.., Response Surface Method(RSM), Kriging Method, and Radial Basis Function(RBF). Three design variables of blade sweep, lean and skew are introduced to optimize the three-dimensional stacking line of the rotor blade. The object function of the shape optimization is selected as an adiabatic efficiency. Throughout the shape optimization of the rotor blade, the adiabatic efficiency is increased for the three different surrogate models. Detailed flow characteristics at the optimal blade shape obtained by different optimization method are drawn and discussed.

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