• Title/Summary/Keyword: Two-dimensional order

Search Result 1,947, Processing Time 0.035 seconds

Numerical Investigation of Bubble Characteristics in a Two-Dimensional Fluidized Bed

  • Kang, Kyung-Tae;Kook, Jeong-Jin;Park, Seung-Ho
    • Journal of the Korean Society of Combustion
    • /
    • v.7 no.1
    • /
    • pp.52-57
    • /
    • 2002
  • A numerical investigation using a commercial CFD program of the Inter-Phase Slip Algorithm has been carried out for detail characteristics of particle motions and bubble behaviors in a two dimensional fluidized bed. The bed simulated has been operated with three different distributor geometries, such as bubble cap, nozzle, and perforated plate types. Experiments using a slit-type two-dimensional fluidized bed and a cylinder-type fluidized bed have been performed in order to confirm the simulation model. In addition, the numerical results are compared with the wellknown correlation of bubble sizes and bubble rising velocities by Mori and Wen [1]. The simulation model that we applied is shown to be useful to understand the relation between bubble behaviors and distributor geometries.

  • PDF

Finite Element Analysis of Beam-and Arch-Like Structures using Higher-Order Theory (고차이론을 이용한 보 및 아치형 구조물의 유한요소 해석)

  • 조진래
    • Computational Structural Engineering
    • /
    • v.10 no.1
    • /
    • pp.185-191
    • /
    • 1997
  • Beam - and arch-like structures are two-dimensional bodies characterized by the fact of small thickness compared to the length of structures. Owing to this geometric feature, linear displacement approximations through the thickness such as Kirchhoff and Reissner-Mindlin theories which are more accessible one dimensional problems have been used. However, for accurate analysis of the behavior in the regions where the state of stresses is complex, two-dimensional linear elasicity or relatively high order of thickness polynomials is required. This paper analyses accuracy according to the order of thickness polynomials and introduces a technique for model combination for which several different polynomial orders are mixed in a single structure.

  • PDF

Tow-dimensional Strain Analysis by Fourier Transform Moire Interferometry (Fourier 변환 모아레 간섭에 의한 이차원적 변형률 해석)

  • Park, T.W.;Shimada, T.;Morimoto, Y.;Han, E.K.
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.12 no.1
    • /
    • pp.16-24
    • /
    • 1992
  • Moire interferometry using a diffraction grating and a laser is a powerful technique for analizing small deformation of a specimen. In the method, the x and y-directional fringe patterns are obtained by using the x and y-directional sets of two beams. If the both sets of two beams are simultaneously incident to the specimen, the x and y-directional fringe patterns are super imposed. In this case, it is difficult to separate each directional fringe pattern. Therefore each fringe pattern has been separately recorded by selecting each set of two beams. In order to analyze a two-dimensional strain changing with time, Moire interferometry using the two-dimensional fourier transform method is proposed and the x and y-directional fringes are separated. By this method, the thermal deformation of a glass plate is analyzed.

  • PDF

Tracking Control of a Electro-hydraulic Servo System Using 2-Dimensional Real-Time Iterative Learning Algorithm (실시간 2차원 학습 신경망을 이용한 전기.유압 서보시스템의 추적제어)

  • 곽동훈;조규승;정봉호;이진걸
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.9 no.6
    • /
    • pp.435-441
    • /
    • 2003
  • This paper addresses that an approximation and tracking control of realtime recurrent neural networks(RTRN) using two-dimensional iterative teaming algorithm for an electro-hydraulic servo system. Two dimensional learning rule is driven in the discrete system which consists of nonlinear output fuction and linear input. In order to control the trajectory of position, two RTRN with the same network architecture were used. Simulation results show that two RTRN using 2-D learning algorithm are able to approximate the plant output and desired trajectory to a very high degree of a accuracy respectively and the control algorithm using two identical RTRN was very effective to trajectory tracking of the electro-hydraulic servo system.

Control of an Electro-hydraulic Servosystem Using Neural Network with 2-Dimensional Iterative Learning Rule (2차원 반복 학습 신경망을 이용한 전기.유압 서보시스템의 제어)

  • Kwak D.H.;Lee J.K.
    • Transactions of The Korea Fluid Power Systems Society
    • /
    • v.1 no.1
    • /
    • pp.1-9
    • /
    • 2004
  • This paper addresses an approximation and tracking control of recurrent neural networks(RNN) using two-dimensional iterative learning algorithm for an electro-hydraulic servo system. And two dimensional learning rule is driven in the discrete system which consists of nonlinear output function and linear input. In order to control the trajectory of position, two RNN's with the same network architecture were used. Simulation results show that two RNN's using 2-D learning algorithm are able to approximate the plant output and desired trajectory to a very high degree of a accuracy respectively and the control algorithm using two same RNN was very effective to control trajectory tracking of electro-hydraulic servo system.

  • PDF

IMPLEMENTATION OF ADAPTIVE WAVELET METHOD FOR ENHANCEMENT OF COMPUTATIONAL EFFICIENCY FOR THREE DIMENSIONAL EULER EQUATION (3차원 오일러 방정식의 계산 효율성 증대를 위한 Adaptive Wavelet 기법의 적용)

  • Jo, D.U.;Park, K.H.;Kang, H.M.;Lee, D.H.
    • Journal of computational fluids engineering
    • /
    • v.19 no.2
    • /
    • pp.58-65
    • /
    • 2014
  • The adaptive wavelet method is studied for the enhancement of computational efficiency of three-dimensional flows. For implementation of the method for three-dimensional Euler equation, wavelet decomposition process is introduced based on the previous two-dimensional adaptive wavelet method. The order of numerical accuracy of an original solver is preserved by applying modified thresholding value. In order to assess the efficiency of the proposed algorithm, the method is applied to the computation of flow field around ONERA-M6 wing in transonic regime with 4th and 6th order interpolating polynomial respectively. Through the application, it is confirmed that the three-dimensional adaptive wavelet method can reduce the computational time while conserving the numerical accuracy of an original solver.

Three-Dimensional Time Varing Magnetic Field Analysis: Using E-$\Omega$ Method (E-$\Omega$ 법을 이용한 3차익 교류 자장 해석)

  • Kim, Dong-Soo;Han, Song-Yup
    • Proceedings of the KIEE Conference
    • /
    • 1989.11a
    • /
    • pp.49-52
    • /
    • 1989
  • Some limits are in two-dimensional analysis by finite element method to electromagnetic machine having finite dimension. Therefore three-dimensional analysis by finite element method, which are modeling original form of models are needed in order to gain accurate solutions. This paper present three-dimensional time varing magnetic field analysis method using electric field E and magnetic scarlar potential $\Omega$, and examine sample model.

  • PDF

The estimation of 3D image using E.O.G (안전위도(EOG)에 의한 입체영상의 평가)

  • Cho, Am
    • Proceedings of the ESK Conference
    • /
    • 1996.04a
    • /
    • pp.168-185
    • /
    • 1996
  • In this research, an investigation of the eye movement was performed when the objects perceived by the eye are three-dimensional objects, two dimensional images, and three dimensional image. This investigation was done by observing the EOG(Electro-oculogram) waves which were achived from experiments. The observed waves were categorized into several groups. Differences among the waves were analyzed for each object and image perceived by the eye. In order to obtain waves to be analyzed, two kinds of experiments were performed. In each experiments, the saccadic eye movement and the smooth pusuit eye movement was considered as an independent variable individually. Waves obtained from the experiments were categorized into 4 types(Wave1, Wave2, Wave3, Wave4) depending on their characteristics. Unlike from the other images, three dimensional image was revealed as a key factor for the active movement of the eye. Futhermore, a unique eye movement was observed in the case of three dimensional image where the focus of the eye was achived in three steps.

  • PDF

The estimation of 3D image using EOG (안전위도(EOG)에 의한 입체영상의 평가)

  • Cho, Am
    • Journal of the Ergonomics Society of Korea
    • /
    • v.16 no.1
    • /
    • pp.1-13
    • /
    • 1997
  • In this research, and investigation of the eye movement was performend when the objects perceived by the eye are three-dimensional objects, two dimensional images, and trhee dimensional images. This investigation was done by observing the EQG(Electro- oculogram) waves which were obtained from experiments. The observed waves were categorized into several groups. Differences among the waves were analyzed for each object and image perceived by the eye. In order to obtain waves for analysis, two kinds of experiments were performen. In each experiment, the saccadic eye movement and the smooth pursuit eye movement were considered as an independent variables. Waves obtained from the experiments were categorized into 4 types (Wave-1, Wave-2, Wave-3, Wave-4) depending on their characteristics. Unlike the other images, three dimensional image was revealed as a key factor for the active movement of the eye. Futhermore, a unique eye movement was observed in the case of three dimensional images where the focus of the eye was achieved through three steps.

  • PDF

Three-Dimensional Transition in the Wake of a Circular Cylinder By Direct Numerical Simulation (DNS에 의한 원주 후류에서의 3차원 천이)

  • Knag, S.J.;Tanahashi, M.;Miyauchi, T.;Mo, J.O.;Lee, Y.H.
    • Proceedings of the KSME Conference
    • /
    • 2001.11b
    • /
    • pp.570-577
    • /
    • 2001
  • Three-dimensional time-dependent flow past a circular cylinder is numerically investigated using direct numerical simulation for Reynolds number 280 and 300. The higher-order finite difference scheme is employed for the spatial distributions along with the second order Adams-Bashforth and the first order backward-Euler time integration. In x-y plane, the convection term is applied by the 5th order upwind scheme and the pressure and viscosity terms are applied by the 4th order central difference. And in spanwise, Navier-Stokes equation is distributed using of Spectral Method. At Reynolds number 259 the two-dimensional wake becomes linearly unstable to a second branch of modes with wavelength about 1.0 diameters at onset (B-mode). Present results of three-dimensional effects of in wake of a circular cylinder is represented with spanwise and streamwise vorticity contours as Reynolds numbers.

  • PDF