• Title/Summary/Keyword: Pressure Interaction

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The Effects of Children's Shame and Communication with Their Parents on Peer Pressure (아동과 청소년의 수치심과 부모와의 의사소통이 또래압력에 미치는 영향)

  • Han, Sae-Young
    • Journal of the Korean Home Economics Association
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    • v.47 no.8
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    • pp.119-130
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    • 2009
  • The purpose of this study was to investigate the interaction and effects of shame and parent-child communication on children and early adolescents' peer pressure. The subjects of this study were 359 children and early adolescents from 5th grade in elementary school to 2nd grade in middle school (187 boys, and 172 girls) in Daejeon city. The results of this research indicated that gender and age played a significant role on the effects of shame and parent-child communication on peer pressure. Open communication with mothers showed a positive relationship with boys' peer pressure, whereas open communication with father showed a negative relationship with boys' peer pressure. The interaction effects of shame and open-communication with fathers and mothers worked differently on peer pressure across gender and age. Interaction effects of shame and open communication with fathers and mothers were significant for boys, but not for girls. Interaction effect of shame and open communication with mothers was significant for children and adolescents.

Weak Normal Shock Wave/Turbulent Boundary Layer Interaction in a Supersonic Nozzle(1st Report, Time-Mean Flow Characteristics) (초음속 노즐에서의 약한 수직충격파와 난류경계층의 간섭(제1편, 시간적평균 흐름의 특성))

  • Hong, Jong-Woo
    • Journal of the Korean Society of Industry Convergence
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    • v.2 no.2
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    • pp.115-124
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    • 1999
  • The interaction of weak normal shock wave with turbulent boundary layer in a supersonic nozzle was investigated experimentally by wall static pressure measurements and by schlieren optical observations. The lime-mean flow in the interaction region was classified into four patterns according to the ratio of the pressure $p_k$ at the first kink point in the pressure distribution of the interaction region to the pressure $p_1$ just upstream of the shock. It is shown for any flow pattern that the wall static pressure rise near the shock foot can be described by the "free interaction" which is defined by Chapman et al. The ratio of the triple point height $h_t$ of the bifurcated shock to the undisturbed boundary layer thickness ${\delta}_1$ upstream of the interaction increases with the upstream Mach number $M_1$, and for a fixed $M_1$, the normalized triple point height $h_t/{\delta}_1$ decreases with increasing ${\delta}_1/h$, where h is the duct half-height.

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Interaction of External Family Support and Economic Pressure on Marital Satisfaction Under the Economic Crisis (경제적 위기 상황에서 결혼 만족도에 대한 가족 외부 지원과 경제적 압박의 상호작용 효과)

  • Kwon, Hee-Kyung
    • Journal of Families and Better Life
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    • v.27 no.5
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    • pp.59-68
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    • 2009
  • External social support for family can be an important resource for families to overcome economic pressure, and can be a way to understand the concept and process of family resilience in the context of Korean economic crisis. To explore the role of external social support that alleviates the negative effects of economic pressure on marital satisfaction, the buffering effects were tested in two ways. First, the interaction effect between external social support and economic pressure on marital satisfaction was tested using hierarchical linear regression model. Second, the scores of marital satisfaction were plotted by the median scores of economic pressure and external social support. Results from the analyses of 191 couples (382 husbands and wives) indicated that external social support help families by buffering the negative effects of economic pressure on marital satisfaction by interacting with economic pressure.

Fluid-Structure Interaction Analysis of Pressure Pulsation in a Suction Pipe of Compressor (압축기 흡입배관 압력 맥동의 유체-구조 연성 해석)

  • Oh, Han-eum;Jeong, Weui-Bong;Ahn, Se-Jin;Kim, Min-sung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.779-780
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    • 2014
  • This paper dealt with numerical estimation of pressure pulsation of the refrigerant in a suction pipe of the compressor. To evaluate the effect of reduction of pressure pulsation, a pipe system with tube was simulated using F.S.I.(Fluid-structure interaction) analysis. A commercial program was used for calculating behavior of pressure. The numerical simulation for pressure ratio of before and after going though internal structure were carried out. As a result, it was verified that the pressure after passing structure is less than the pressure before passing internal structure depending on the longitudinal frequency of structure.

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Two-Dimensional Analysis of Unsteady Flow Through One Stage of Axial Turbine (II) (1단 축류 터빈의 비정상 내부유동특성에 관한 2차원 해석 (II))

  • Park, Jun-Young;Um, In-Sik;Baek, Je-Hyun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.25 no.11
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    • pp.1518-1526
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    • 2001
  • In this paper, the mechanism of unsteady potential interaction and wake interaction in one stage axial turbine is numerically investigated at design point in two-dimensional viewpoint. The numerical technique used is the upwind scheme of Van-Leer's Flux Vector Splitting (FVS) and Cubic spline interpolation is applied on zonal interface between stator and rotor. The inviscid analysis is used to embody the influence of potential interaction only and viscous analysis is used to embody the influences of both potential interaction and wake interaction at the same time. The potential-flow disturbance from the stator into a rotor passage and the periodic blockage effect of rotor produce the unsteady pressure on the blade surface in inviscid analysis. After the wake is cut by rotor, two counterrotating votical patterns flanking the wake centerline in the passage are generated. So, these phenomena magnify the unsteady pressure in viscous analysis than that in inviscid analysis. The resulting unsteady forces on the rotor, generated by the combined interaction of the two effects by potential and wake interaction, are discussed.

2-D Inviscid Analysis of Flow in One Stage of Axial Compressor (1단 축류압축기 내부 유동의 2차원 비점성 해석)

  • Kim HyunIl;Park JunYoung;Baek JeHyun;Jung HeeTaek
    • Journal of computational fluids engineering
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    • v.5 no.2
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    • pp.38-46
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    • 2000
  • It has been indicated that the rotor/stator interaction has distinct causes of unsteadiness, such as the viscous vortex shedding, wake/stator interaction and potential rotor/stator interaction. In this paper, the mechanism of unsteady potential interaction in one stage axial compressor is numerically investigated for blade row ratio 1:1 and 2:3 at design point and for blade row ratio 2:3 at off-design point in two-dimensional view point. The numerical technique used is the upwind scheme of Van-Leer's Flux Vector Splitting(FVS) and Cubic spline interpolation is applied on zonal interface. In this study the flow unsteadiness due to potential interaction are found to be larger in blade row ratio 2:3 than in 1:1. The total pressure rise in blade row ratio 2:3 is closer to the real value in design point than that in 1:1. The change of unsteady pressure amplitude according to the variation of stator exit pressure is very small.

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Development of a Computational Method of 3-D Unsteady Incompressible Flow in Turbomachinery (터보기계내의 3차원 비정상 비압축성 유동계산방법의 개발)

  • Kim, Bbong-Kyun;Park, Jae-In;Joo, Won-Gu;Cho, Kang-Rae
    • The KSFM Journal of Fluid Machinery
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    • v.2 no.2 s.3
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    • pp.57-63
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    • 1999
  • The flow through multistage turbomachinery is affected by the interaction between a rotor and a stator. The interaction is due to the inviscid potential effect and viscous effect between closely spaced rotor and stator airfoils. Three-dimensional, unsteady, incompressible Navier-Stokes equations with a standard $k-{\epsilon}$ model are solved using a non-staggered grid system. This method is applied to the flow through a multistage compressor measured by Stauter et al. The results have shown strong interaction between the rotating and stationary flow field. The decay of rotor wake and the pressure profiles agree very well with experimental data. The wake produced by rotor causes unsteady pressure on the surface of a stator. The rotor/stator interaction produces the unsteady pressure force on the rotor and stator blades.

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Experimental Study on the Merged Angle of Mixed-Interaction Regions of Sprays from Two Pressure-Swirl Injectors (스월 분사기 분무 혼합충돌지역에서의 중첩각도에 관한 실험적 연구)

  • Yi, Young-Sun;Hong, Moon-Geun;Lee, Soo-Yong
    • Journal of ILASS-Korea
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    • v.16 no.4
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    • pp.195-200
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    • 2011
  • The pressure-swirl atomizer is widely used for the injectors in liquid rocket engines thanks to its high performance atomization and broad stability margin range. Spray mixed-interaction is an important area of study especially in cases where the propellant is mixed by spray interaction after an oxidant and a fuel are discharged separately. This interaction of sprays results in a significant modification of the spray characteristics such as the spatial evolution of the sprays. Experiments are conducted by a photographic technique to quantify the merged angle of the interaction regions of sprays from two pressure-swirl injectors. The experimental results show that the merged angle is mainly determined by the momentum flux ratios between two swirled sprays.

A Study on the Formulation of the Interaction Problem between Upper Structure and the Ground under Consolidation (上部 構造와 下部 壓密地盤 間 상호작용 문제의 정식화에 대한 연구)

  • Lee, Oe-Duck
    • Journal of Ocean Engineering and Technology
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    • v.13 no.1 s.31
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    • pp.51-61
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    • 1999
  • When a structure is built on the ground under consolidation, the instant corresponding contact pressure which the upper structure exerts on the ground is established. But, as the consolidation of the ground proceeds, the contact pressure is changed because of the flexural rigidity of the upper structure. This varied contact pressure exerts influence on the consolidation behavior of the ground. And, this varied consolidation behavior exerts on the contact pressure in retum. This kind of interaction between the upper struture and the olwer ground under consolidation contimues till all the consolidation process in finished. So this problem cannot be defined as a linear problem. In this paper an approximation method which can analyse this non-linear interaction problem is proposed by the FEM.

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Rationally modeling collapse due to bending and external pressure in pipelines

  • Nogueira, Andre C.
    • Earthquakes and Structures
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    • v.3 no.3_4
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    • pp.473-494
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    • 2012
  • The capacity of pipelines to resist collapse under external pressure and bending moment is a major aspect of deepwater pipeline design. Existing design codes present interaction equations that quantify pipeline capacities under such loadings, although reasonably accurate, are based on empirical data fitting of the bending strain, and assumed simplistic interaction with external pressure collapse. The rational model for collapse of deepwater pipelines, which are relatively thick with a diameter-to-thickness ratio less than 40, provides a unique theoretical basis since it is derived from first principles such as force equilibrium and compatibility equations. This paper presents the rational model methodology and compares predicted results and recently published full scale experimental data on the subject. Predictive capabilities of the rational model are shown to be excellent. The methodology is extended for the problem of pipeline collapse under point load, longitudinal bending and external pressure. Due to its rational derivation and excellent prediction capabilities, it is recommended that design codes adopt the rational model methodology.