• Journal of the korean Society of Automotive Engineers
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• v.11 no.3
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• pp.29-36
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• 1989

A multidimensional numerical simulation for flows in an engine with axisymmetric geometry was performed. Three kinds of differencing schemes, namely, skew upwind differencing scheme (SUDS), interpolated upwind differencing scheme (IUDS), upwind differencing scheme (UDS), are used in a comparative study. Simultaneously, the effects of the artificial dampings and the grids on numerical results are estimated. Compared with the measurements, the calculations with SUDS and proper artificial damping show very similar qualitative tendency with observed results. But there are some discrepancies due to numerical errors and unclear boundary conditions.

• 한국전산유체공학회:학술대회논문집
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• 1998.11a
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• pp.78-83
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• 1998

A finite-difference method based on conservative supra characteristic method(CSCM) type upwind flux difference splitting has been studied on the bluntness effect on the wall heat transfer rate and wall pressure over blunt-body. The results show that the stagnation heating varies inversely with the square root of the nose radius.

• 한국전산유체공학회:학술대회논문집
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• 2006.10a
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• pp.74-75
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• 2006

Recently much attention has been drawn to meshfree method since conventional methods such as FDM, FVM and FEM have suffered from difficulty with mesh generation for complex geometry and deformable bodies. In this paper, an upwind point collocation meshfree method developed by the authors is applied to two shock wave diffraction problems. One is the shock diffraction over a 90-degree corner and the other is the single Mach reflection on a ramp. The scheme showed stability and the results showed accuracy.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.17 no.1
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• pp.29-45
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• 2013

Central schemes offer a simple and versatile approach for computing approximate solutions of nonlinear systems of hyperbolic conservation laws. However, there are large numerical dissipation in case of contact discontinuity. We study semi-discrete central upwind scheme by changing flux functions to reduce the numerical dissipation and we perform numerical computations for various problems in case of contact discontinuity.

• Kyungpook Mathematical Journal
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• v.61 no.2
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• pp.309-322
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• 2021

A conservative scheme for solving scalar hyperbolic equations is presented using a quadrature rule and an ODE solver. This numerical scheme consists of an upwind part, plus a correction part which is derived by introducing a new variable for the given hyperbolic equation. Furthermore, the stability and accuracy of the derived algorithm is shown with numerous computations.

• Journal of computational fluids engineering
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• v.10 no.1
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• pp.99-106
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• 2005

Performance of first, second and third order accurate methods for calculation of in viscid fluxes in fluid flow governing equations are investigated here. For the purpose, an upwind method based on Roe's scheme is used to solve 2-dimensional Euler equations. To increase the accuracy of the method two different schemes are applied. The first one is a second and third order upwind-based algorithm with the MUSCL extrapolation Van Leer (1979), based on primitive variables. The other one is an upwind-based algorithm with the Chakravarthy extrapolation to the fluxes of mass, momentum and energy. The results show that the thickness of shock layer in the third order accuracy is less than its value in second order. Moreover, applying limiter eliminates the oscillations near the shock while increases the thickness of shock layer especially in MUSCL method using Van Albada limiter.

• Communications of the Korean Mathematical Society
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• v.17 no.1
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• pp.103-120
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• 2002

A second order upwind method for linear hyperbolic systems is studied in this paper. The method approximates solutions as piecewise linear functions, and state variables and slopes of the linear functions for next time step are computed separately. We present a new method for the computation of slopes, derived from an upwinding difference for a derivative. For nonoscillatory solutions, a monotonicity algorithm is also proposed by modifying an existing algorithm. To validate our second order upwind method, numerical results for linear advection equations and linear systems for elastic and acoustic waves are given.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.579-584
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• 2000

Algebraic Reynolds Stress (ARS) model is applied in order to analyze the turbulent flow of wall-attaching offset jet and to evaluate the model's predictability. The applied numerical schemes are upwind scheme and skew-upwind scheme. The numerical results show good prediction in first order calculations (i.e., reattachment length, mean velocity, pressure), while they show slight deviations in second order (i.e., kinetic energy and turbulence intensity). By comparison with the previous results using $k-{\varepsilon}$ model, ARS model predicts better than the standard $k-{\varepsilon}$ model, however, predicts slightly worse than the $k-{\varepsilon}$ model including the streamline curvature modification. Additionally this study can reconfirm that skew-upwind scheme has approximately 25% improved predictability than upwind scheme.

• Journal of the Korean Society for Precision Engineering
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• v.8 no.4
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• pp.23-32
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• 1991

The paper discusses the problem of the flow over the backward facing step and the offset jet, which are calculated numerically. Standard k- .epsilon. model and its LPS modification are used as turbulence models. Hybrid central/upwind scheme and skew- upwind scheme are used as numerical schemes. The numerical scheme has a strong influence on the offset jet rather than the flow over backward facing step. The skew-upwind scheme gives good results in both cases. However, the k- .epsilon. model with LPS modification yields no remarkable improvements in the predictions of both flows. The skew-upwind scheme improves the prediction of reattachment length in the offset jet.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.807-810
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• 2002

The suitability of high-order accurate, central and upwind-biased compact difference schemes is evaluated for the large-eddy simulations of flows in complex geometry. Two flow geometries are considered: channel and circular cylinder. The effects of numerical dissipation and aliasing error on the evaluation of subgrid scale stress are investigated by extending the analysis by Ghosal (1) to centered and upwind compact schemes. It is shown that the failure of upwind schemes mainly comes from the aliasing error.