(1 일목 ) 제 3 발표장 47 이은택 1, 안형택 2* SIMULATION ON FLOW PAST A CIRCULAR CYLINDER USING UNSTRUCTURED MESH BASED INCOMPRESSIBLE FLUID SOLVER(ULSAN3D) E. Lee and H.T. Ahn 1. 1.1 Navier-Stokes Navier-Stokes. (1) (2),,. (1)-(2). (3) (4) (4)(Artificail Compressibility term). Corresponding author E-mail: htahn@ulsan.ac.kr (5). ULSAN3D[1,2,3,4] 3. 2. Fig. 1 3. 3.,
48 제 3 발표장 (1 일목 ). meshes, Computers & Fluids, Vol. 170(15), pp.187-196. [5] 2004, Williamson, C. H. K. and Govardhan, R., Vortex-Induced Vibrations, Annual Review of Fluid Mechanics, Vol.36, pp.413-455. Fig. 1 Unstructured mesh for the simulation Fig. 2 Unstructured mesh near circular cylinder [1] 2006, Ahn, H. T., and Kallinderis, Y., Strongly coupled flow/structure interaction with a geometrically conservative ALE scheme on general hybrid meshes, Journal of Computational Physics, Vol.219, No.2, pp.671-696. [2] 2018, Ahn, H. T., Lee, E., Luo, H., Cell-centered High-order Hyperbolic Finite Volume Method for Diffusion Equation on Unstructured Grids, Journal of Computational Physics, Vol.355, pp.464-491. [3] 2005, Kallinderis, Y., and Ahn, H. T., Incompressible Navier-Stokes method with general hybrid meshes, Journal of Computational Physics, Vol.210, No.1, pp.75-108. [4] 2018, Lee, E, and Ahn, H. T., A reconstruction-based cell-centered high-order finite volume method for incompressible viscous flow simulation on unstructured
(1 일목 ) 제 3 발표장 49 김덕훈 1, 안형택 2* AN ANALYSIS OF FLOW AROUND A GOLF BALL USING UNSTRUCTURED GRID BASED INCOMPRESSIBLE FLOW SOLVER (ULSAN3D) D.H. Kim and H.T. Ahn 1. ULSAN3D [1, 2, 3, 4]. 2. 2.1 ULSAN3D Navier-Stokes.,, p. (1) 2.2 4, 2. (2) (artificial compressibility) (3). (3) Corresponding author E-mail: htahn@ulsan.ac.kr Fig. 1 Unstructured Grid of Fluid Field around Golf Ball
50 제 3 발표장 (1 일목 ) Fig. 2 Unstructured Grid of Fluid Field [1] 2006, Ahn, H. T., and Kallinderis, Y., Strongly coupled flow/structure interaction with a geometrically conservation ALE scheme on general hybrid meshes, Journal of Computational Physics, Vol.219, No.2, pp.671-696. [2] 2017, Ahn, H. T., Lee, E., Luo, H., Cell-centered High-order Hyperbolic Finite Volume Method for Diffusion Equation on Unstructured Grids, Journal of Computational Physics. [3] 2005, Kallinderis, Y., and Ahn, H. T., Incompressible Navier-Stokes method with general hybrid meshes, Journal of Computational Physics, Vol.210, No.1, pp.75-108. [4] 2017, Lee, E, and Ahn, H. T., A reconstruction-based cell-centered high-order finite volume method for incompressible viscous flow simulation on unstructured meshes, Computer & Science. Fig. 3 Unstructured Grid of Fluid Field
(1 일목 ) 제 3 발표장 51 고석원 1, 정세민 2* A FUNDAMENTAL STUDY FOR THE GRIDLESS SIMULATION OF TWO-DIMENSIONAL UNSTEADY INCOMPRESSIBLE TURBULENT FLOWS S.W. Ko and S.M. Jeong 1. CFD, (Eulerain frame), (Structured grid) (Unstructured grid), (FVM, Finite Volume Method).,,., (Gridless method), (Lagrangian),. 2,. 2. [1]. Corresponding author E-mail: smjeong@chosun.ac.kr 2.1 2 RANS(Reynolds Averaged Naiver-Stokes). (1) (2),,,,,. 0.09. 2.2 Standard, (Wall function). (3) (4)
52 제 3 발표장 (1 일목 ) (a) (b) Fig. 1 Schematic view of cloud composition,,,, 1.00, 1.30, 1.44, 1.92. 2.3 Cloud, 45, 2, 8 Cloud, (5) (Weighing function). (5) 2.4 Fractional step. 2.1 2.2 Cloud 2, (Residual) 2 (WMLS; Weighted Moving Least-Squares). 2 Adams-Bashforth. (Poisson) 2, SOR(Successive Over-Relaxation). (8),, (9)., (10). Fig. 2 Comparison of -velocity profiles (7) (8) 3.. x Fig. 2. Blasius,. 4. WMLS standard,. [1] 2009, Jeong, S.M., Park, J.C. and Heo, J.K., Numerical study on two-dimensional incompressible viscous flow based on gridless method, Journal of Computational Fluid Engineering Vol.14, No.4, pp.93-100 (6)
(1 일목 ) 제 3 발표장 53 권현진 1, 장세명 2* ANALYSES THE ONE DIMENSIONAL LINEAR EQUATION USING WENO SCHEME AND DISCONTINUOUS GALERKIN METHOD H.J. Kwon and S.M. Chang 1... WENO [1], [2]. WENO Stencil (interpolation),. (numerical oscillation). WENO 1. 2. 2.1 1. Corresponding author E-mail: smchang@kunsan.ac.kr (1). 2.2 WENO WENO (semi-discretization). 2.3 (1)(shape function) Green (weak form). (numerical approximate solution). Lagrange polynomial, Lax-Friedrich. Minmod (slope limiter). Minmod.
54 제 3 발표장 (1 일목 ) 3. 3.1 (1) ((4))( (5)). sin (periodic condition), 3 TVD Runge-Kutta. 3.2 Table. 1 Convergence test at N error order error order 20 5.22E-03-1.80E-02 - DG 40 1.31E-03 2.00 2.39E-03 2.17 80 3.27E-04 2.00 5.56E-04 2.10 160 8.18E-05 2.00 1.34E-04 2.05 20 7.68E-04-1.49E-03 - WENO5 40 2.34E-05 5.04 4.66E-05 4.94 80 7.24E-07 5.00 1.15E-06 5.08 160 2.26E-08 5.00 4.47E-08 5.09 2 WENO 5. Fig.1 (5) 10 100. Fig.1 WENO. Fig.1 WENO. 3. 2 WENO. WENO. WENO. WENO Minmod [3,4].. (NRF) (2016R1D1A3B01015543). 1.1 1 0.9 0.8 DG P 1 WENO5 Exact 1.1 1 0.9 0.8 DG P 1 WENO5 Exact u 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0-0.1 0 0.25 0.5 0.75 1 x Fig.1 Comparison of the exact and numerical solutions for the linear case: 10 periodic(left) and 100 periodic(right) u -0.1 0 0.25 0.5 0.75 1 x Table. 1 (4)., [3]. 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 [1] 1996, Jiang, G.S., and Shu, C.W, Efficient Implementation of Weighted ENO Schemes, Journal of Computational Physics, Vol.126, pp.202-208. [2] 2007, Hesthaven, J.S., and Warburton, T., Nodal Discontinuous Galerkin Methods: Algorithm, Analysis, and Application, Springer Science & Business Media, pp.51-63. [3] 2005,,,,,, pp.82-85. [4] 2014,.,. 1,, Vol.34(5), pp.1383-1393.
(1 일목 ) 제 3 발표장 55 송승호 1, 최정일 2* BLAST WAVE PROPAGATION AFTER HIGH ENERGY EXPLOSION OF REAL GAS S.H. Song and J.-I. Choi 1.. [1] Riemann., MUSCL(Monotonic upwind scheme for conservation laws)[2]. 2..,, Breakaway., 20KTon. Riemann flux difference splitting Roe s method[3].,. Srinivasan et al.[4] curve fit Riemann. / (convex).. [1] 2014, Song, S., Lee, C. and Choi, J-I., Numerical Simulation of Initial Fireball after Nuclear Explosion, Journal of Computational Fluids Enegineering, Vol. 19, pp. 45-51. [2] 1979, B.V. Leer, Towards the ultimate conservative difference scheme V. A second order sequel to Gudunov s method, Journal of Computational Physics, Vol 32, 101-136 [3] 1999, E.F. Toro, Riemann Solvers and Numerical Methods for Fluid Dynamics, Springer-Verlag, Berlin [4] 1987, Srinivasan, S. et al., Simplified Curve Fits for the Thermodynamic Properties of Equilibrium Air., NASA Reference Publication 1181. Corresponding author E-mail: jic@yonsei.ac.kr