• Title/Summary/Keyword: similarity solution

Search Result 292, Processing Time 0.025 seconds

An Experimental Study on the Similarity of Confined Coaxial Jets (동축 이중제한분류의 상사성에 대한 실험적 연구)

  • 사용철;이태환;이준식
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.19 no.5
    • /
    • pp.1291-1299
    • /
    • 1995
  • In confined coaxial jets, the flow-mixing characteristics depend on the initial conditions at the nozzle outlet such as velocity ratio and nozzle radius ratio. In this study, nozzle ratio(inner/outer) was 0.3. Longitudinal axial velocity, turbulent intensity and Reynolds shear stress were measured by CTA. Measurements were made from the duct inlet to the region where similarity solution could exist. This study investigated flow charicteristics according to the variation of similitude parameter which was derived from the theory of Craya-Cutet. The range of similarity region depends on the variation of the similitude patameter. The form factor obtained from the axial velocity profile in the similarity region was constant. The higher the similitude parameter, the wider the spread rate of the jets. Due to this fact, the similarity conditions developed more quickly and the region where the similarity holds became narrow. Present experimental data confirmed the validity of Craya-Curtet theory.

A study on effect of heat transfer of condensation including noncondensable gas over a flat plate (불응축가스가 평판위 응축열전달에 미치는 영향에 관한 연구)

  • 양대일;정형호
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.24 no.1
    • /
    • pp.25-30
    • /
    • 2000
  • In present paper, mass transfer over a flat plate with film condensation including noncondesable gas is analyzed with the help of similarity methods. Couette flow was assumed in liquid film and boundary-layer approximation was used in the ambient flow. Governing equations were transformed into the ordinary differential equtions by the similarity methods. Runge-Kutta and shooting method were used in order to fine the effect of mass transfer on the velocity and concentrations at the liquid-vapor interface.

  • PDF

Developing a Three-dimensional Spectral Model Using Similarity Transform Technique (유사변환기법을 이용한 3차원 모델의 개발)

  • Kang, Kwan-Soo;So, Jae-Kwi;Jung, Kyung-Tae;Sonu, Jung Ho
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.5 no.2
    • /
    • pp.107-120
    • /
    • 1993
  • This paper presents a new modal solution of linear three-dimensional hydrodynamic equations using similarity transform technique. The governing equations are first separated into external and internal mode equations. The solution of the internal mode equation then proceeds as in previous modal models using the Galerkin method but with expansion of arbitrary basis functions. Application of similarity transform to resulting full matrix equations gives rise to a set of uncoupled partial differential equations of which the unknowns are coefficients of mode vector. Using the transform technique a computationally efficient time integration is possible. In present from the model use Chebyshev polynomials for Galerkin solution of internal mode equations. To examine model performance the model is applied to a homogeneous, rectangular basin of constant depth under steady, uniform wind field.

  • PDF

A Case Study on Teaching Solutions Exploration of Wythoff's Game through Using the Analogy for the Elementary Gifted Class (초등학교 영재학급에서 유추를 활용한 위도프 게임의 해법 탐구 지도 방법)

  • Bae, Sin Young;Song, Sang Hun
    • Journal of Educational Research in Mathematics
    • /
    • v.25 no.1
    • /
    • pp.95-111
    • /
    • 2015
  • The purpose of this study is to analyze cases on teaching solutions exploration of Wythoff's game through using the analogy for the gifted elementary students, to suggest useful teaching methods. Students recognized structural similarity among problems on the basis of relevance of conditions of problems. The discovery of structural similarity improves the ability to solve problems. Although 2 groups-NIM game with surface similarity is not helpful in solving Wythoff's game, Queen's move game with structural similarity makes it easier for students to solve Wythoff's game. Useful teaching methods to find solutions of Wythoff's game through using the analogy are as follow. Encoding process helps students make sense of the game. It is significant to help students realize how many stones are remained and how the location of Queen can be expressed by the ordered pair. Inferring process helps students find a solution of 2 groups-NIM game and Queen's move game. It is necessary to find a winning strategy through reversely solving method. Mapping process helps students discover surface similarity and structural similarity through identifying commonalities between the two games. It is crucial to recognize the relationship among the two games based on the teaching in the Encoding process. Application process encourages students to find a solution of Wythoff's game. It is more important to find a solution by using the structural similarity of the Queen's move game rather than reversely solving method.

An Incremental Similarity Computation Method in Agglomerative Hierarchical Clustering

  • Jung, Sung-young;Kim, Taek-soo
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.11 no.7
    • /
    • pp.579-583
    • /
    • 2001
  • In the area of data clustering in high dimensional space, one of the difficulties is the time-consuming process for computing vector similarities. It becomes worse in the case of the agglomerative algorithm with the group-average link and mean centroid method, because the cluster similarity must be recomputed whenever the cluster center moves after the merging step. As a solution of this problem, we present an incremental method of similarity computation, which substitutes the scalar calculation for the time-consuming calculation of vector similarity with several measures such as the squared distance, inner product, cosine, and minimum variance. Experimental results show that it makes clustering speed significantly fast for very high dimensional data.

  • PDF

An Analysis of Similarities that Students Construct in the Process of Problem Solving (중학생들이 수학 문장제 해결 과정에서 구성하는 유사성 분석)

  • Park Hyun-Jeong;Lee Chong-Hee
    • Journal of Educational Research in Mathematics
    • /
    • v.16 no.2
    • /
    • pp.115-138
    • /
    • 2006
  • The purpose of this paper is to investigate students' constructing similarities in the understanding the problem phase and the devising a plan phase of problem solving. the relation between similarities that students construct and how students construct similarities is researched through case study. Based on the results from the research, authors reached a conclusion as following. All of two students constructed surface similarities in the beginning of the problem solving process and responded to the context of the problem information sensitively. Specially student who constructed the similarities and the difference in terms of a specific dimension by using diagram for herself could translate the equation which used to solve the base problem or the experienced problem into the equation of the target problem solution. However student who understood globally the target problem being based on the surface similarity could not translate the equation that she used to solve the base problem into the equation of target problem solution.

  • PDF

The Effect of Heat Conduction resistance on Laminar Film Condensation along a Horizontal Plate (수평평판의 막응축에서 전도 열저항의 영향)

  • Lee, Euk-Soo
    • Proceedings of the Korean Society of Marine Engineers Conference
    • /
    • 2005.06a
    • /
    • pp.183-188
    • /
    • 2005
  • The effect of heat conduction resistance on laminar film condensation of the pure saturated vapor in forced flow over a flat plate has been investigated as boundary layer solutions. A efficient numerical methods for water are proposed for its solution. The momentum and energy balance equations are reduced to a nonlinear system of ordinary differential equations with four parameters: the Prandtl number, Pr, Modified Jacob number, $Ja^{\ast}/Pr$, defined by an overall temperature difference, a property ratio $\sqrt{P_l{\mu}_l/P_v{\mu}_v}$ and the conjugate parameter ${\zeta}$. The similarity and simplified solutions obtained reveal the effects of the conjugate parameter.

  • PDF

An Analytic Analysis for a Two-Dimensional Floating and Fluid-Filled Membrane Structure (부유식 유체저장용 2차원 막구조물의 이론적 해석)

  • Choi, Yoon-Rak
    • Journal of Ocean Engineering and Technology
    • /
    • v.23 no.4
    • /
    • pp.32-37
    • /
    • 2009
  • An analytic similarity shape solution was studied for a two-dimensional floating and fluid-filled membrane structure. The static shape of a membrane structure can be expressed as a set of nonlinear ordinary differential equations. The integration of curvature leads to an analytic solution for the shape, which contains unknown boundary values. Matching the upper and lower shapes at the free surface incorporated with their buoyancy allowed the unknowns to be determined. Some characteristic values of similarity shapes were evaluated and shapes are illustrated for various density ratios and volume efficiency ratios.

Analytical Solution of Multi-species Transport Equations Coupled with a First-order Reaction Network Under Various Boundary Conditions (다양한 경계조건을 가진 일차 반응 네트워크로 결합된 다종 오염물 거동 해석해)

  • Suk, Hee-Jun;Chae, Byung-Gon
    • Journal of Soil and Groundwater Environment
    • /
    • v.16 no.6
    • /
    • pp.46-57
    • /
    • 2011
  • In this study, analytical solution of multip-species transport equations coupled with a first-order reaction network under constant concentration boundary condition or total flux boundary condition is obtained using similarity transformation approach of Clement et al. (2000). The study shows the schematic process about how multi-species transport equations with first-order sequential reaction network is transformed through the similarity transformation approach into independent and uncoupled single species transport equations with first-order reaction. The analytical solution was verified through the comparison with popular commercial programs such as 2DFATMIC and RT3D. The analytical solution can be utilized in nuclear waste sites where radioactive contaminants and their daughter products occur and in industrial complex cities where chlorinated solvent such as PCE, TCE, and its biodegradation products produces. In addition, it can help the verification of the developed numerical code.

Similarity rule of Seepage failure by Centrifuge model test (원심모형시험기를 이용한 사면의 침투 및 파괴에 관한 상사법칙의 검토)

  • Kim, Jae-Young;Jun, Tohda
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2004.03b
    • /
    • pp.313-318
    • /
    • 2004
  • When plan breakdown by permeation of fill dam, bank by original decision scale model test of sound, original decision scale model test of sound that destroy having used water was carried out. And original decision scale model test of sound that use viscous fluid is carried out, but doubt remains in experiment result in state that verification of law of similarity is not achieved. In this study, verified according to Modeling of Models' method effecting law of similarity to use n ship horoscope solution of water.

  • PDF