• 제목/요약/키워드: Boundary effect

검색결과 2,972건 처리시간 0.036초

Investigation of anti-wear additives for synthetic esters; Amine salts of phosphonic acid

  • Hasegawa, T.;Minami, I.;Kidera, Y.;Hirao, K.;Memita, M.
    • 한국윤활학회:학술대회논문집
    • /
    • 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
    • /
    • pp.269-270
    • /
    • 2002
  • Antiwear(AW) properties of phoshphonic acid derivatives for trimethylolpropane (TMP) esters were investigated under boundary conditions. AW effect of dialkyl phosphonates depends on polarity of base fluid. They provide good AW performance in less polar TMP esters, whereas their AW effect is not sufficient in polar TMP esters. Amine salts of phosphonic acid were developed as new AW additiνe system for TMP esters. They provide excellent AW performance even in polar TMP esters.

  • PDF

경계 조건이 가스터빈 블레이드 냉각공기 유량에 미치는 영향 (Effect of Boundary Conditions on Internal Coolant Flow in Gas Turbine Blades)

  • 신지영;박병규
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2001년도 춘계학술대회논문집D
    • /
    • pp.559-564
    • /
    • 2001
  • Advanced gas turbine engines employ turbine entry temperatures so high that cooling of the turbine blades is essential. The coolant flow introduces losses which need to be minimized, and therefore it is important that the minimum amount of coolant is used. This work presents the result of the one-dimensional analysis and the effect of the boundary conditions on coolant flow rate in gas turbine blades.

  • PDF

PZT계의 정방정상과 능면체정상의 경계조성에 대한 기계적 응력과 전기장의 영향 : 열역학적 고찰 (The Effect of Mechanical Stress and Electric Field on the Morphotropic Tetragonal and Rhombohedr Phase Boundary in PZT System : Thermodynamic Consideration)

  • 천채일;김호기
    • 한국세라믹학회지
    • /
    • 제30권10호
    • /
    • pp.859-865
    • /
    • 1993
  • Morphotropic tetragonal and rhombohederal phase boundary(MPB) in PZT system was calculated and the effect of mechanical stress and electric field on the MPB was examined using phenomenological thermodynamic theory proposed by Devonshire. Mechanical stress and electric field was calculated to change free energies of phases and shift MPB. The stable composition range of the phase, of which spontaneous strain and spontaneous polarization aligned to the direction of tensile stress or electirc field, was expanded.

  • PDF

부식 배관의 경계조건이 파손확률에 미치는 영향 (Effect of Boundary Conditions on Failure Probability of Corrosion Pipeline)

  • 이억섭;편장식
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2002년도 춘계학술대회 논문집
    • /
    • pp.873-876
    • /
    • 2002
  • This paper presents the effect of internal corrosion, external corrosion, material properties, operation condition, earthquake, traffic load and design thickness in pipeline on the failure prediction using a failure probability model. A nonlinear corrosion is used to represent the loss of pipe wall thickness with time. The effects of environmental, operational, and design random variables such as a pipe diameter, earthquake, fluid pressure, a corrosion rate, a material yield stress and a pipe thickness on the failure probability are systematically investigated using a failure probability model for the corrosion pipeline.

  • PDF

이상 스테인레스강의 변형거동에 미치는 질소의 영향 (Effects of Nitrogen on Deformation Behavior of Duplex Stainless Steel)

  • 이형직;장영원
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 2003년도 춘계학술대회논문집
    • /
    • pp.49-52
    • /
    • 2003
  • The effects of nitrogen on the deformation behavior of duplex stainless steel have been studied The variation of strength was correlated with the characteristic microstructures. Analysis based on Hall-Petch relation confirmed that nitrogen enhances phase-boundary strengthening effect. The evolution of dislocation structure, slip traces, and misorientation distribution during deformation were also characterized to elucidate the effect of nitrogen on inelastic deformation mechanism.

  • PDF

부식 배관의 경계조건이 파손확률에 미치는 영향 (Effect of Boundary Conditions on failure Probability of Corrosion Pipeline)

  • 이억섭;편장식
    • 한국신뢰성학회:학술대회논문집
    • /
    • 한국신뢰성학회 2002년도 정기학술대회
    • /
    • pp.403-410
    • /
    • 2002
  • This paper presents the effect of internal corrosion, external corrosion, material properties, operation condition, earthquake, traffic load and design thickness in pipeline on the failure prediction using a failure probability model. A nonlinear corrosion is used to represent the loss of pipe wall thickness with time. The effects of environmental, operational, and design random variables such as a pipe diameter, earthquake, fluid pressure, a corrosion rate, a material yield stress and a pipe thickness on the failure probability are systematically investigated using a failure probability model for the corrosion pipeline.

  • PDF

초소성변형특성에 미치는 소성변형랴의 영향 (The Effect of Plastic Strain on the Superplastic Deformation Behavior)

  • 권용남;장영원
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 1997년도 춘계학술대회논문집
    • /
    • pp.291-293
    • /
    • 1997
  • The effect of strain accumulation on the superplastic deformation behavior has been investigated through a series of load relaxation tests. The experimental results were analyzed using the recently proposed inelastic constitutive theory. The superplastic deformation of fine grained materials is confirmed to consist of grain boundary sliding and accommodating grain matrix deformation. However the flow behavior is changed with the plastic strain. It is believed that the microstructural changes such as grain growth and cavitation affect the superplastic deformation behaviors.

  • PDF

경계조건에 따른 가스터빈 블레이드 냉각공기 유량변화 (Effect of Boundary Condition on the Flow Rate of the Internal Coolant in Gas Turbine Blades)

  • 신지영;박병규
    • 설비공학논문집
    • /
    • 제13권9호
    • /
    • pp.888-894
    • /
    • 2001
  • Advanced gas turbine engines employ turbine entry temperatures so high that cooling of the turbine blades is essential. The coolant flow introduces losses which need to be minimized, and therefore it is important that the minimum amount of coolant should be used. This work presents the result of the one-dimensional analysis and the effect of the boundary conditions on coolant flow rate in gas turbine blades.

  • PDF

Slit-Coater 노즐에서 Photo Resist의 유동 특성 (Flow Characteristics of Photo Resist in a Slit-Coater Nozzle)

  • 김장우
    • 반도체디스플레이기술학회지
    • /
    • 제3권3호
    • /
    • pp.37-40
    • /
    • 2004
  • This study presents numerical solutions of three-dimensional laminar flow-field formed by photo resist flow in a slit-coater model. We discuss on the governing equations, laminar viscosities and the computational model applied in our numerical calculation and some results. We prove that the structure of tapered-cavity aid to make uniform pressure-field and boundary effect is an important problem to improve coating uniformity. In view of uniformity improvement, it is necessary to study for the structure of cavity and flow path.

  • PDF

Laplace변환을 이용한 판 진동문제의 경계적분방정식 정식화 (A Boundary Integral Formulation for Vibration Problems of Plate using Laplace Transform)

  • 이성민;서일교;권택진
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 1994년도 봄 학술발표회 논문집
    • /
    • pp.9-16
    • /
    • 1994
  • In this paper, a boundary integral equation for transient plate bending problem is proposed. Approach, using laplace transform is considered. The boundary integral equations with respect to deflection, normal slope, bending moment effective shear are presented and the effect of corner point is considered.

  • PDF