Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of computational fluids engineering
Journal Basic Information
Journal DOI :
Korea Society of Computational Fluids Engineering
Editor in Chief :
Volume & Issues
Volume 12, Issue 4 - Dec 2007
Volume 12, Issue 3 - Sep 2007
Volume 12, Issue 2 - Jun 2007
Volume 12, Issue 1 - Mar 2007
Selecting the target year
WIND PRESSURE TRANSIENTS ON PLATFORM SCREEN DOOR OF ISLAND PLATFORMS IN A SUBWAY STATION CAUSED BY A PASSING TRAIN
Lee, Myung-Sung ; Won, Chan-Shik ; Hur, Nahm-Keon ;
Journal of computational fluids engineering, volume 12, issue 3, 2007, Pages 1~7
In the present study, the wind pressure transients on platform screen door in island platform caused by a passing train are investigated numerically. The transient compressible 3-D full Navier-Stokes solution is obtained with actual operational condition of subway train and the moving mesh technique adopted for the train movement. To achieve more accurate results, detailed shape of train is included in a computational domain and the entrance and exit tunnel of platform are also modeled. Numerical analyses are conducted on three operational conditions of different velocity variation.
DESIGN OF WATER INJECTION NOZZLE OF BIDET WITH COMPUTATIONAL FLUID DYNAMICS
Choi, Y.S. ; Yang, S.S. ; Jin, S.W. ;
Journal of computational fluids engineering, volume 12, issue 3, 2007, Pages 8~12
An optimized bidet nozzle design to form the required swirl water jet is proposed with the help of numerical analysis. The bidet can do the cleaning process of human body by water injection and the speed/pressure/injection angle/magnitude of swirl intensity of water jet determine the cleaning capability and personal subjective feeling. The objective of this research is to design optimal water injection nozzle to make stable swirl intensity. The effect of individual design variables are analyzed from the basic design and the final design is deduced to make high performance water jet within the pre-determined operation conditions.
NUMERICAL ANALYSIS ON THE HEAT TRANSFER AND FLOW IN THE SHELL AND TUBE HEAT EXCHANGER
Lee, Sang-Hyuk ; Lee, Myung-Sung ; Hur, Nahm-Keon ;
Journal of computational fluids engineering, volume 12, issue 3, 2007, Pages 13~19
A numerical simulation on the heat transfer and flow field was carried out to improve the performance of the shell and tube heat exchanger. The steady incompressible 3-D Navier-Stokes solution is obtained with the actual operational condition and geometry of the heat exchanger. Based on this study, it is noted that the present geometry of the heat exchanger causes poor heat transfer since the air inside shell does not flow through the tube bundle, but around it. The enhancement of the heat transfer can be achieved by the variation of the design factor like the sealing strip located on the top/bottom and middle of the baffle, but it causes the increasement of the pressure drop. In this paper, the effects of the location and size of the sealing strips and flow rate through the heat exchanger on the heat transfer and pressure drop are studied.
A STUDY ON THE NURBS GRID GENERATION AND GRID CONTROL
Yoon, Yong-Hyun ;
Journal of computational fluids engineering, volume 12, issue 3, 2007, Pages 20~28
A fast and robust method of grid generation to multiple functions has been developed for flow analysis in three dimensional space. It is based on the Non-Uniform Rational B-Spline(NURBS) of an approximation method. Many of NURBS intrinsic properties are introduced and much more easily understood. The grid generation method, details of numerical implementation. examples of application, and potential extensions of the current method are illustrated in this paper. The object of this study is to develop the surface grid generation and the grid cluster techniques capable of resolving complex flows with shock waves, expansion waves, shear layers. The knot insert method of Non-Uniform Rational B-Spline seems well worked. In addition, NURBS has been widely utilized to generate grids in the computational fluid dynamics community. Computational examples associated with practical configurations have shown the utilization of the algorithm.
DEVELOPMENT OF AN HIGH-ORDER IMPLICIT DISCONTINUOUS GALERKIN METHOD ON UNSTRUCTURED MESHES
Lee, H.D. ; Kwon, O.J. ;
Journal of computational fluids engineering, volume 12, issue 3, 2007, Pages 29~40
An implicit discontinuous Galerkin method for the two-dimensional Euler equations was developed on unstructured triangular meshes. The method can achieve high-order spatial accuracy by using hierachical basis functions based on Legendre polynomials. Numerical tests were conducted to estimate the convergence order of numerical solutions to the Ringleb flow and the supersonic vortex flow for which analytic solutions are available. Also, the flows around a 2-D circular cylinder and an NACA0012 airfoil were numerically simulated. The numerical results showed that the implicit discontinuous Galerkin methods couples with a high-order representation of curved solid boundaries can be an efficient method to obtain very accurate numerical solutions on unstructured meshes.
DIRECT NUMERICAL SIMULATION OF IMMISCIBLE GAS BUBBLE DISPLACEMENT IN 2D CHANNEL
Shin, S. ;
Journal of computational fluids engineering, volume 12, issue 3, 2007, Pages 41~46
Dynamic behavior of immiscible gas bubble attached to the wall in channel flow plays very important role in many engineering applications. Special attention has been paid to micro direct methanol fuel cell(
DMFC) where surface tension becomes dominant factor with minor gravitational effect due to its reduced size. Therefore, displacement of
bubble generating on a cathode side in
DMFC can be very difficult and efficient removal of
bubbles will affect the overall machine performance considerably. We have focused our efforts on studying the dynamic behavior of immiscible bubble attached to the one side of the wall on 2D rectangular channel subject to external shear flow. We used Level Contour Reconstruction Method(LCRM) which is the simplified version of front tracking method to track the bubble interface motion. Effects of Reynolds number, Weber number, advancing/receding contact angle and property ratio on bubble detachment characteristic has been numerically identified.
THERMAL-FLUID PERFORMANCE ANALYSIS OF COMPACT HEAT EXCHANGERS HAVING A PERIODIC CHANNEL CONFIGURATION
Kim, M.H. ; Lee, W.J. ;
Journal of computational fluids engineering, volume 12, issue 3, 2007, Pages 47~54
A periodic CFD approach for the performance analysis of compact high temperature heat exchangers is introduced and applied to selected benchmark problems, which are a fully developed 2D laminar heat transfer, a conjugate heat transfer between parallel plates which have exact solutions, and a heat transfer in a real high temperature heat exchanger module. The results for the 2D laminar heat transfer and the 2D conjugate heat transfer showed a very good agreement with the exact solutions. For the high temperature heat exchanger module, the pressure drops were predicted well but some difference was observed in the temperature parameters when compared to the full channel CFD analysis due to assumptions introduced into the periodic approach. Considering its assumptions and simplicities, however, the results showed that the periodic approach provides physically reasonable results and it is sufficient to predict the performance of a heat exchanger within an engineering margin and with much less CPU time than the case of a full channel analysis.
ANALYSIS OF A STRATIFIED NATURAL CONVECTION FLOW WITH THE SECOND-MOMENT CLOSURE
Choi, Seok-Ki ; Kim, Seong-O ;
Journal of computational fluids engineering, volume 12, issue 3, 2007, Pages 55~61
A computational study on a strongly stratified natural convection is performed with the elliptic blending second-moment closure. The turbulent heat flux is treated by both the algebraic flux model (AFM) and the differential flux model (DFM). Calculations are performed for a turbulent natural convection in a square cavity with conducting top and bottom walls and the calculated results are compared with the available experimental data. The results show that both the AFM and DFM models produce very accurate solutions with the elliptic-blending second-moment closure without invoking any numerical stability problems. These results show that the AFM and DFM models for treating the turbulent heat flux are sufficient for this strongly stratified flow. However, a slight difference between two models is observed for some variables.
A CONCEPTUAL DESIGN OF RADIATIVE THERMAL CONTROL SYSTEM IN A GEOSTATIONARY SATELLITE OPTICAL PAYLOAD
Kim, Jung-Hoon ; Jun, Hyoung-Yoll ;
Journal of computational fluids engineering, volume 12, issue 3, 2007, Pages 62~68
A conceptual thermal design is performed for the optical payload system of a geostationary satellite. The optical payload considered in this paper is GOCI(Geostationary Ocean Color Imager) of COMS of Korea. The radiative thermal control system is employed in order to expect a small thermal gradient in the telescope structure of GOCl. Two design margins are applied to the dedicated radiator dimensioning, and three kinds of configuration to the heater power sizing. A Monte-Carlo ray tracing method and a network analysis method are utilized to calculate radiative couplings and thermal responses respectively. At the level of conceptual design, sizing thresholds are presented for the radiator and heater on the purpose of determining the mass and power budget of the spacecraft.