• Title/Summary/Keyword: diameter profile

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Numerical Study of the Supersonic Turbine Performance Variation with respect to the Rotor Profile Diameter (터빈 동익의 프로파일 정의 위치에 따른 초음속 터빈 성능변화에 대한 전산해석 연구)

  • Park, Pyun-Goo;Jeong, Eun-Hwan;Kim, Jin-Han
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2007.11a
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    • pp.297-301
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    • 2007
  • The blades of supersonic turbines with low aspect ratio are usually designed to have the same cross sectional shape in radial direction. The profile diameter definition of turbines may lead to produce unintended flow passage area variations resulting performance degradation. In this paper, the effects of profile diameter definition on the supersonic impulse turbine performance have been investigated. Computational results of three different profile diameters are compared. It has been found that flow passage area variation can be achieved according to designer's intention when blade profile is defined at rotor tip diameter. Furthermore, the turbine blade profile defined at rotor tip showed better performance than the others.

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Effect of constitutive equations on theoretical analysis in melt spinning process

  • Kim, Seong-Cheol;Oh, Tae-Hwan;Han, Sung-Soo;Lyoo, Won-Seok
    • Korea-Australia Rheology Journal
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    • v.21 no.3
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    • pp.149-153
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    • 2009
  • Profile development of the melt spinning process of poly(ethylene terephthalate) (PET) was simulated by a numerical method under the consideration of two constitutive equations of Newtonian and upper convected Maxwell (UCM) models. The viscoelastic characteristics of the polymer were considered via UCM constitutive equation that considered relaxation time as a function of temperature and molecular weight. The UCM model predicted the diameter profile better than the Newtonian, while velocity development was slower than the Newtonian model. Viscoelasticity played an important role in accurately predicting diameter profile. However, even though neck-like deformation was observed in the UCM model, the exact position of the deformation under high speed spinning was not obtained.

Issues on the Machining of 3D-Profile for Automotive Press Dies (자동차 프레스 금형을 위한 3차원 윤곽가공의 문제점)

  • Lee S. H.;Chung Y. C.;Ju S. Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2002.02a
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    • pp.19-25
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    • 2002
  • Profile machining using cutter diameter compensation is widely used in die and mould manufacturing. Especially automotive die makers try to use 3D-profile machining for trimming or flange dies. But the technological requirements and implementation issues haven't been defined. In this paper we summarized the requirements and issues of 3D-profile machining. Approximation of input profiles into sequences of line and helical arc is the first major issue. The second major issue is removing cutter interference from the approximated curves holding z-values when the maximum cutter diameter is given. Keeping constant machining width, local machining, path linking problems and several detail technological requirements are also discussed.

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Issues on the Machining of 3D-Profile for Automotive Press Dies (자동차 프레스 금형을 위한 3차원 윤곽가공의 문제점)

  • 이상헌;정연찬;주상윤
    • Korean Journal of Computational Design and Engineering
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    • v.7 no.3
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    • pp.141-147
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    • 2002
  • Profile machining using cutter diameter compensation is widely used in die and mould manufacturing. Especially automotive die makers try to use 3D-profile machining for trimming or flange dies. But the technological requirements and implementation issues haven't been defined. In this paper we summarized the requirements and issues of 3D-profile machining. Approximation of input profiles into sequences of line and helical arc is the first major issue. The second major issue is removing cutter inter- ference from the approximated curves holding z-values when the maximum cutter diameter is given. Keeping constant machining width, local machining, path linking problems and several detail technological requirements are also discussed.

Determination of Optimal Blank Diameter for the High Precision of Spindle Screw (고정도 Spindle Screw 전조공정에서의 최적 소재경 선정)

  • 김광호;김동환;김병민
    • Transactions of Materials Processing
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    • v.11 no.8
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    • pp.710-715
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    • 2002
  • This paper describes the numerical determination of optimum blank diameter for sound material flow and high precise thread profile of a spindle screw through external thread rolling using two-three roll dies. Initial blank diameter affects the dimensional accuracy and surface finish qualities of a spindle screw in thread rolling process, therefore it is very important to determine the optimum blank diameter in thread rolling process. In order to determine the optimum blank diameter, this paper suggests the calculation method of initial bland diameter considering the real shape of tooth. The finite element code DEFORM is applied to analyze the metal flow of tooth, and these analytical results are verified by thread rolling experiment for spindle screw.

Analysis of roll deformation for sendzimir rolling mill (젠지미어 압연기 롤 변형해석)

  • 이영호;김종택;한석영;이준정;김종근
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.6
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    • pp.1689-1699
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    • 1990
  • Sendzimir rolling mill is widely used for rolling hard materials such as stainless steel due to its small work roll diameter and shape controllability using two effective actuators, AS-U-Roll crown adjustment and lst. intermediate roll shifting. However, in comparison with 4-high or 6-high mills, it is noteasy to get good strip or excellent flatness because Z-mill has small diameter of work rolls which are easily deformed by load. A new mathematical model based on the method of dividing roll and strip into multo-portions was used to develop strip profile prediction software. Using the developed software, several influencing factors related to rolled strip profile for Z-Mill were tested analytically and characterized for the effective shape control. The effects of adjusting shape control actuators of Z-Mill on strip profile were also examined and discussed in detail.

Characteristics Evaluation of Process Parameters for Improvement the Precision of Thread ]tolling in Lead Screw (Lead Screw 전조 정밀도 향상을 위한 성형인자의 특성평가)

  • 김광호;김동환;고대철;김병민
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.312-315
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    • 2002
  • This paper summarizes the results of a numerical study conducted to analyze the effect of selected process parameters on material flow and thread profile in thread rolling of large diameter blanks. Based on the previous work where a plane strain mode was found to provide a reasonable approximation of the thread rolling process, the effect of varying thread form, friction factor, flow stress, and blank diameter on effective strain and thread height was analyzed using the finite element code DEFORM. This study show that effective strain for flank angle, that blank diameter had important effect on the as-rolled thread while flow stress, friction factor, and crest round of dies had significant impact on effective strain at the thread root and crest and load of thread rolling. While the rate of strain harding was found to have an effect on the crest profile, the results indicate that it is the primary factor responsible for seam formation in rolled threads.

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Determination of optimum blank diameter for the high precision of Spindle Screw (전조시 Spindle Screw의 정밀도 향상을 위한 최적 소재경 선정)

  • 김광호;김동환;김병민
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2002.05a
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    • pp.133-137
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    • 2002
  • This paper summarizes the results of a numerical study conducted to analyze the determination of optimum blank diameter on material flow and thread profile for Spindle Screw in external thread rolling. Initial blank diameter affect a quality of Spindle Screw in thread rolling process. Therefore, it is very important to determine the optimum blank diameter in thread rolling process. In order to determine the optimum blank diameter, this paper suggest the calculating method of initial blank diameter considering real shape of tooth. The finite element code DEFORM is applied to analyze the metal flow of tooth. then the analytical results are verified by experiment of thread rolling for Spindle Screw.

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A Study on Automated Outer Diameter Measurement System for Axisymmetric Automotive Part (자동차용 축대칭 형상 부품 외경 자동측정시스템에 관한 연구)

  • Ban, Kap-Soo;Bae, Jun-Young
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.3
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    • pp.61-68
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    • 2013
  • Automatic measurement system is required since cycle time and cost of production are increased by various factors in manual systems. This paper presents a machine vision based prototype measurement system for the automotive axisymmetric shape parts which are generally measured by a manual system that is required the tolerance of the part is very small on each machined surface. This measurement system adopts a method in which optical lens is transferred along the profile of the part to minimize measurement cycle time. The main interest of this paper is a development of an optimum measurement algorithm to the outside diameter of the parts that can be applied to various combinations of hardware. The operating system used to implement the whole system is Window XP and corresponding environment.

Analysis of stability on steel D&I can (Steel D&I Can의 안정성 해석)

  • Cho, S.J.;You, C.S.;Jung, S.W.;Park, H.C.;Hwang, W.;Han, K.S.
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.471-476
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    • 2001
  • The main object of this study is to develop a reliable FEM simulation technique for stability test using ABAQUS software and to clarify the effect of base profile of a steel D&I(drawn and ironed) can on the dome reversal pressure. For the can after body making simulation, two kind of stability test, dome buckle test and axial crush test are performed. The factors studied in the base profile on the dome reversal pressure are the base diameter, the rim radius, the dome shoulder radius, the dome radius and the dome depth. Within the limits before the occurrence of normal snap-through buckling of dome, the dome reversal pressure is improved by decreasing the base diameter, increasing the dome depth or increasing the dome shoulder depth.

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