• Title/Summary/Keyword: 환상

Search Result 620, Processing Time 0.028 seconds

The effects of thermal conductivities of component materials on the heat flowerates in composite longitudinal and annular fin assemblies (직선 및 환상의 composite fin assembly에서 구성 재질들의 열전도율들이 열유동량에 미치는 영향)

  • Jo, J. C.
    • Journal of the korean Society of Automotive Engineers
    • /
    • v.8 no.3
    • /
    • pp.37-45
    • /
    • 1986
  • 열교환기의 확장 표면이 2가지 또는 3가지의 서로 다른 재질들로써 구성되는 경우, 직선 및 환상 의 Composit Fin Assembly에서 구성 재질들의 열전도율들이 각 Assembly 에서의 온도 분포와 열유동량에 미치는 영향을 조사하였다. Composite Fin Assembly에서의 온도 분포를 구하기 위 하여 유한 요소법을 사용하여 수치 계산하였다. Composite Fin Assembly를 구성하는 재료들의 열전도율들이 열유동량에 미치는 효과는 상당히 크며, 따라서 확장 표면의 설계 계산에 있어서 이러한 효과들을 필수적으로 고려하여야 함이 밝혀졌다.

  • PDF

Atomization of Annular Liquid Sheet with Core Air Flow - SMD Variation with Gas/Liquid Injection Velocity (중심 공기류를 이용한 환상 액막 미립화에 관한 연구-기/액 분사유속에 따른 입경 변화 고찰)

  • Choi, Chul-Jin;Lee, Sang-Yong
    • Proceedings of the KSME Conference
    • /
    • 2001.06e
    • /
    • pp.131-135
    • /
    • 2001
  • The atomization characteristics of an annular liquid (water) sheet of small radius with a core gas (air) flow were studied. Different sizes of annular gaps (0.2, 0.4 and 0.8 mm) were tested to find the effect of liquid sheet thickness on SMD. The inner diameter of the gas port for the core gas flow was 4 mm. Cross-section averaged SMD was measured for various liquid and gas velocities. Regions of the SMD decrease with the increase of the liquid velocity always existed regardless of the liquid sheet thickness. This attributes to the transition of the flow patterns of spray and also to the aerodynamic interaction between the atomizing gas and the ripples on the liquid sheet surface.

  • PDF

Prediction of Defect Formation in Ring Rolling by the Three-Dimensional Rigid-Plastic Finite Element Method (3차원 강소성 유한요소법을 이용한 환상압연공정중 형상결함의 예측)

  • Moon Ho Keun;Chung Jae Hun;Park Chang Nam;Joun Man Soo
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.28 no.10
    • /
    • pp.1492-1499
    • /
    • 2004
  • In this paper, defect formation in ring rolling is revealed by computer simulation of ring rolling processes. The rigid-plastic finite element method is employed for this study. An analysis model having relatively fine mesh system near the roll gap is used for reducing the computational time and a scheme of minimizing the volume change is applied. The formation of the central cavity formation defect in ring rolling of a taper roller bearing outer race and the polygonal shape defect in ring rolling of a ball bearing outer race has been simulated. It has been seen that the results are qualitatively good with actual phenomena.

A Study of MMOPRG Background Story based on Fantasy Theory (환상의 범주에 따른 MMORPG의 세계관 연구)

  • Ahn, Jin-Kyoung;Lyou, Chul-Gyun
    • Journal of Digital Contents Society
    • /
    • v.9 no.2
    • /
    • pp.349-356
    • /
    • 2008
  • MMORPG which offers a utopian world that includes a different rule from the real to satisfy players' needs for escape from the real world has changed. In these days, MMORPGs which have a unique world than middle-age fantasy have appeared as a new experience field. This paper compares MMORPGs have a middle-aged fantasy background story like J.R.R. Tolkein with another types bases on fantasy theory and presents difference.

  • PDF

Natural convection heat transfer in a horizontal annulus from an inner tube with two vertical fins (2개의 수직휜이 부착된 내관으로부터 환상공간내의 자연대류 열전달)

  • 정태현;정한식;권순석
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.15 no.2
    • /
    • pp.654-660
    • /
    • 1991
  • Natural convection heat transfer in a horizontal annulus from an inner tube with two vertical fins has been studied for the effects of dimensionless fin length and Rayleigh number. The maximum local Nusselt number of inner tube was obtained at .theta. = 145.deg. and that of outer cylinder at .theta. = 0.deg. for the case of $l_{F}$=0.3 Local Nusselt number distributions for the lower fins show higher values than that of the upper fins. The mean Nusselt number of inner tube was increased with the values of dimensionless fin length. The mean Nusselt number can be represented in an exponential function of Grashof number at various fin lengths. As compared with experimental and numerical results, isotherms and local Nusselt number show good agreement.t.

Effects of Bottom Inflow Area on Pool Boiling Heat Transfer in a Vertical Annulus (하부 유로단면적이 수직 환상공간 내부 풀비등열전달에 미치는 영향)

  • Kang, Myeong-Gie;Yoo, Joo-Sik
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.31 no.7 s.262
    • /
    • pp.604-610
    • /
    • 2007
  • To investigate effects of the inflow area on pool boiling heat transfer in a vertical annulus, the inflow area at its bottom has been changed from 0 to $1060.3mm^2$. For the test, a heated tube of 34 mm diameter and water at atmospheric pressure have been used. To elucidate effects of the inflow area on heat transfer results of the annulus are compared to the data of a single unrestricted tube. The change in the inflow area at the bottom of the annulus results in much variation in heat transfer coefficients. When the inflow area is $113.1mm^2$ the deterioration point of heat transfer coefficients gets moved up to the higher heat fluxes because of the convective flow at the bottom regions.