• Title/Summary/Keyword: 동력해석

Search Result 946, Processing Time 0.021 seconds

Dynamic Analysis of Marine Drilling Riser (해저자원개발을 위한 Riser의 동력학적 연구)

  • Han, Nam Soo;Yun, Chung Bang
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.4 no.2
    • /
    • pp.65-75
    • /
    • 1984
  • A comparative study between several methods for the marine drilling riser analysis is carried out. One static analysis method and four dynamic methods are studied. The dynamic analysis methods used are two time domain methods using regular and random waves, and two frequency domain methods using the conventional and an improved linearization techniques. Two different sizes of risers are investigated. The analysis model of the structure is based on the beam-column element with lateral wave/current loads in a vertical plane. The forces on the riser are calculated using a modified farm of the Morison's equation. The finite element method is used to solve the equation for several wave/current conditions.

  • PDF

Dust collector strainer and carbon filter pressure permeation analysis (흡연집진기 내 스트레이너 및 카본필터 압력투과 해석)

  • Lee, Chi-Woo
    • Journal of Power System Engineering
    • /
    • v.19 no.4
    • /
    • pp.5-10
    • /
    • 2015
  • Dust collector is one of the most widely used equipment among the method of separating particles, it filters exhaust gas having various kinds of dusts through several filters installed on parallel. This research investigated the moving characteristic of Honeycomb-type carbon filter in pressure drop of smoking collector's ventilation system. It also compared pressure transmission coefficient through pressure drop according to flow velocity change.

The study for roof hood structure of G7 power car engine compartment using air flow analysis. (G7 동력차 동력실 유동해석을 통한 루프후드 구조 연구)

  • 박광복;장규호;이동훈
    • Proceedings of the KSR Conference
    • /
    • 2000.05a
    • /
    • pp.634-644
    • /
    • 2000
  • The study was carried out about the roof hood structure of power car for Korean High Speed Train. The compatibility for applied material and volume of hood duct was studied using analysis about heat and flow distributions. The materials and volume of duct were mainly determined by output air temperature and flow rate of each electric blocks. This report was described, which focuses on pressure distribution and air temperature within engine compartment of power car.

  • PDF

Applied Rock Mechanics - Safety and Control of the Environmental (제 1주제 암반공학, 환경안전과 제어)

  • van der Merwe, J. Nielen
    • Tunnel and Underground Space
    • /
    • v.9 no.4
    • /
    • pp.281-282
    • /
    • 1999
  • 제 1주제에는 총 106편의 논문이 접수되었으며, 이 논문들의 내용, 성격, 해석방법 등을 정리하였다. 일반적으로 논문의 수준은 모두 우수했으며, 구두발표를 위한 논문을 선정하는데 어려움이 있었다. 해석적인 방법에 있어서는 수치해석 방법이, 계측에 있어서는 직접 계측방법이 가장 일반적으로 사용되었다. 논문 면 수에 제한이 있었기 때문에 대부분의 저자들은 자세한 해석내용을 생략하고 있었다. 특이한 점은 암석역학과 유체동력학과의 접합이라 할 수 있으며, 암반 안전성에 미치는 시간의 영향 등에 대한 연구가 계속적으로 이루어져야 한다.

  • PDF

Numerical Investigation of Effects of Tip Clearance Height on Fan Performance and Tip Clearance Flow in an Axial Fan of the Cooling Tower (냉각탑용 축류팬의 팁 간격이 팬 성능 및 틈새 유동에 미치는 영향에 관한 수치해석적 연구)

  • Oh, Keon-Je
    • Journal of Power System Engineering
    • /
    • v.16 no.1
    • /
    • pp.44-50
    • /
    • 2012
  • 팁 간격의 크기가 냉각탑용 축류팬의 성능과 누설 유동에 미치는 영향을 조사하기 위해서 서로 다른 2가지 팁 간격을 가진 경우에 대해서 점성유동을 해석하였다. 케이싱 내에서 작동하는 축류팬 주위의 유동을 연속방정식, Navier-Stokes 방정식 등을 지배방정식으로 사용하여 수치해석 하였다. 난류유동에 나타나는 레이놀즈 응력은 ${\kappa}-{\epsilon}$ 난류모델을 사용하여 계산하였다. 전체적으로 H형 격자계를 사용하였으며, 팁 주위의 유동을 해석하기 위해서 팁 영역 주위에 부분적으로 조밀한 격자를 두었다. 팁 간격이 증가하면 누설 유동의 증가로 인한 유동 손실의 증가로 전압상승과 수력효율이 감소하였다. 팬 직경에 대한 팁 간격이 0.4%에서 1.0%로 증가하면 전압상승 값이 약 10% 정도 감소하였으며, 수력효율은 약 3% 정도 감소하였다. 팁 간격이 팁 근처 날개 주위의 압력에 미치는 영향을 보면, 팁 간격이 증가하여 누설 유동이 증가하면 흡입면과 압력면의 압력차가 전연 부근에서 감소함을 알 수 있었다. 누설 와류의 중심은 코드를 따라서 흡입면으로 부터 떨어져 나가면서 형성됨을 알 수 있었다. 누설 와류의 위치를 보면 팁 간격이 증가하면 와류 중심의 위치가 흡입면 쪽으로 이동하고, 흡입면에서 떨어진 거리도 날개 후반부에서 증가 폭이 커지는 포물선 형태로 증가함을 알 수 있었다.

Performance Analysis of Autorotation(2) : Performance of High Speed Autorotaion (자동회전의 성능해석(2) : 고속 자동회전의 성능)

  • Kim, Hak-Yoon
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.40 no.1
    • /
    • pp.12-22
    • /
    • 2012
  • Performance variation of autorotating rotor was investigated. The shaft angle of the rotor is reduced while the flight velocity is increased. The BO-105 helicopter rotor blade was replaced by untwisted NACA 0012 airfoil and the rotor was simulated by using Transient Simulation Method(TSM) to judge the autorotation region for the variables. To simulate the compressibility effect at high speed flight, two-dimensional aerodynamic data was analyzed by compressible Navier-Stokes solver and Pitt/Peters inflow theory was adopted to simulate the induced velocity field. Thrust and lift coefficients, lift to drag ratio variations were investigated, also the lift and power were compared to those of BO-105 helicopter. Sharing lift and power between the autorotating rotor and wing was considered when the compound aircraft concept is introduced.

Exergy Analysis of Regenerative Wet-Compression Gas-Turbine Cycles (습식 압축을 채용한 재생 가스터빈 사이클의 엑서지 해석)

  • Kim, Kyoung-Hoon;Kim, Se-Woong;Ko, Hyung-Jong
    • Journal of Energy Engineering
    • /
    • v.18 no.2
    • /
    • pp.93-100
    • /
    • 2009
  • An exergy analysis is carried out for the regenerative wet-compression Brayton cycle which has a potential of enhanced thermal efficiency owing to the reduced compression power consumption and the recuperation of exhaust energy. Using the analysis model, the effects of pressure ratio and water injection ratio are investigated on the exergy efficiency of system, exergy destruction ratio for each component of the system, and exergy loss ratio due to exhaust gas. The results of computation for the typical cases show that the regenerative wet-compression gas turbine cycle can make a notable enhancement of exergy efficiency. The injection of water results in a decrease of exergy loss of exhaust gas and an increase of net power output.

A Study on Mass Flow Control and FEA of Plate Spring Attached in Piezoelectric Ceramic (세라믹 압전체에 부착된 판 스프링의 유한요소해석과 질량 흐름 제어에 관한 연구)

  • Lee, S.K.;Kim, Y.S.
    • Journal of Power System Engineering
    • /
    • v.7 no.4
    • /
    • pp.61-66
    • /
    • 2003
  • In this paper, the relation between displacement of piezoelectric material and electric field was proposed. FEA was introduced to predict the displacement and reaction force of plate spring attached in the piezoelectric material. The relation between displacement of piezoelectric material forced by plate spring and applied electric field were further verified by experimental investigation. Also, the flow rate of gas in piezoelectric valve was examined by experiment. Finally, the relation between electric field and gas flow was derived. Based on these results, these relations can be used in the design of mass flow controller.

  • PDF

Performance and Safety Analysis of Marine Solid Oxide Fuel Cell Power System (선박동력용 SOFC시스템의 성능 및 안전성 해석)

  • Kim, Myoung-Hwan
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.33 no.2
    • /
    • pp.233-243
    • /
    • 2009
  • The strengthened regulations for atmospheric emissions from ships like MARPOL Annex VI have caused a necessity of new, alternative power system in ships for the low pollutant emissions and the high energy efficiency. This paper attempts to investigate the configuration of SOFC system for LNG tanker taking into account the safety and to analyze the influence of design parameters on the system performance. The simulation results provide the basic data for the design and efficiency improvement of SOFC system and indicate the guidelines for the safe system operation.

A Study on Screw Expander for Power Generation (동력발생용 스크루우 팽창기에 관한 연구)

  • ;;工藤一彦
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.10 no.4
    • /
    • pp.568-576
    • /
    • 1986
  • 본 연구에서는 포하수 혹은 팽창기를 열매체로한 스크루우팽창기의 회전자회 전각에 의한 회전자간체적변화, 흡입구의 면적변화, 팽창기내에서의 누설통로에서의 임계등의 기하학적 특성과 흡입구와 누설통로에서의 임계유속을 고헌한 해석프로그램 을 개발하여 회전자회전수 흡입열매체의 건도, 흡입.토출압력비 그리고 팽창기내부에 서의 누설등의 효과에 대한 해석을 행하여 스크루우 팽창기의 동력발생기로서의 실용 성을 검토하였다.