• Title/Summary/Keyword: G-Navier-stokes equations

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DERIVATION OF THE g-NAVIER-STOKES EQUATIONS

  • Roh, Jaiok
    • Journal of the Chungcheong Mathematical Society
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    • v.19 no.3
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    • pp.213-218
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    • 2006
  • The 2D g-Navier-Stokes equations are a certain modified Navier-Stokes equations and have the following form, $$\frac{{\partial}u}{{\partial}t}-{\nu}{\Delta}u+(u{\cdot}{\nabla})u+{\nabla}p=f$$, in ${\Omega}$ with the continuity equation ${\nabla}{\cdot}(gu)=0$, in ${\Omega}$, where g is a suitable smooth real valued function. In this paper, we will derive 2D g-Navier-Stokes equations from 3D Navier-Stokes equations. In addition, we will see the relationship between two equations.

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THE GLOBAL ATTRACTOR OF THE 2D G-NAVIER-STOKES EQUATIONS ON SOME UNBOUNDED DOMAINS

  • Kwean, Hyuk-Jin;Roh, Jai-Ok
    • Communications of the Korean Mathematical Society
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    • v.20 no.4
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    • pp.731-749
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    • 2005
  • In this paper, we study the two dimensional g-Navier­Stokes equations on some unbounded domain ${\Omega}\;{\subset}\;R^2$. We prove the existence of the global attractor for the two dimensional g-Navier­Stokes equations under suitable conditions. Also, we estimate the dimension of the global attractor. For this purpose, we exploit the concept of asymptotic compactness used by Rosa for the usual Navier-Stokes equations.

GEOMETRY OF L2(Ω, g)

  • Roh, Jaiok
    • Journal of the Chungcheong Mathematical Society
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    • v.19 no.3
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    • pp.283-289
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    • 2006
  • Roh[1] derived 2D g-Navier-Stokes equations from 3D Navier-Stokes equations. In this paper, we will see the space $L^2({\Omega},\;g)$, which is the weighted space of $L^2({\Omega})$, as natural generalized space of $L^2({\Omega})$ which is mathematical setting for Navier-Stokes equations. Our future purpose is to use the space $L^2({\Omega},\;g)$ as mathematical setting for the g-Navier-Stokes equations. In addition, we will see Helmoltz-Leray projection on $L^2_{per}({\Omega},\;g)$) and compare with the one on $L^2_{per}({\Omega})$.

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ASYMPTOTIC BEHAVIOR OF STRONG SOLUTIONS TO 2D g-NAVIER-STOKES EQUATIONS

  • Quyet, Dao Trong
    • Communications of the Korean Mathematical Society
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    • v.29 no.4
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    • pp.505-518
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    • 2014
  • Considered here is the first initial boundary value problem for the two-dimensional g-Navier-Stokes equations in bounded domains. We first study the long-time behavior of strong solutions to the problem in term of the existence of a global attractor and global stability of a unique stationary solution. Then we study the long-time finite dimensional approximation of the strong solutions.

FINITE ELEMENT ANALYSIS FOR A MIXED LAGRANGIAN FORMULATION OF INCOMPRESSIBLE NAVIER-STOKES EQUATIONS

  • Kim, Hong-Chul
    • Journal of the Korean Mathematical Society
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    • v.34 no.1
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    • pp.87-118
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    • 1997
  • This paper is concerned with a mixed Lagrangian formulation of the wiscous, stationary, incompressible Navier-Stokes equations $$ (1.1) -\nu\Delta u + (u \cdot \nabla)u + \nabla_p = f in \Omega $$ and $$ (1.2) \nubla \cdot u = 0 in \Omega $$ along with inhomogeneous Dirichlet boundary conditions on a portion of the boundary $$ (1.3) u = ^{0 on \Gamma_0 _{g on \Gamma_g, $$ where $\Omega$ is a bounded open domain in $R^d, d = 2 or 3$, or with a boundary $\Gamma = \partial\Omega$, which is composed of two disjoint parts $\Gamma_0$ and $\Gamma_g$.

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PULLBACK ATTRACTORS FOR 2D g-NAVIER-STOKES EQUATIONS WITH INFINITE DELAYS

  • Quyet, Dao Trong
    • Communications of the Korean Mathematical Society
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    • v.31 no.3
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    • pp.519-532
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    • 2016
  • We consider the first initial boundary value problem for the 2D non-autonomous g-Navier-Stokes equations with infinite delays. We prove the existence of a pullback $\mathcal{D}$-attractor for the continuous process associated to the problem with respect to a large class of non-autonomous forcing terms.

STABILIZATION OF 2D g-NAVIER-STOKES EQUATIONS

  • Nguyen, Viet Tuan
    • Communications of the Korean Mathematical Society
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    • v.34 no.3
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    • pp.819-839
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    • 2019
  • We study the stabilization of 2D g-Navier-Stokes equations in bounded domains with no-slip boundary conditions. First, we stabilize an unstable stationary solution by using finite-dimensional feedback controls, where the designed feedback control scheme is based on the finite number of determining parameters such as determining Fourier modes or volume elements. Second, we stabilize the long-time behavior of solutions to 2D g-Navier-Stokes equations under action of fast oscillating-in-time external forces by showing that in this case there exists a unique time-periodic solution and every solution tends to this periodic solution as time goes to infinity.

Discretization of Pressure-Poisson Equation for Solving Incompressible Navier-Stokes Equations Using Non-Staggered Grid (정규격자를 사용한 비압축성 Navier-Stokes 방정식의 수치해석을 위한 압력 Poisson 방정식의 이산화)

  • Kim Y. G.;Kim H. T.;Kim J. J.
    • 한국전산유체공학회:학술대회논문집
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    • 1998.11a
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    • pp.96-101
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    • 1998
  • Various discretiation methods of Laplacian operator in the Pressure-Poisson equation are investigated for the solution of incompressible Navier-Stokes equations using the non-staggered grid. Laplacian operators previously proposed by other researchers are applied to a Driven-Cavity problem. The computational results are compared with those of Ghia. The results show the characteristics of the discrete Laplacian operators.

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Optimization Design of Cascade with Rotor-Stator Interaction Effects (정익과 동익의 상호작용을 고려한 익렬의 공력 최적 설계)

  • Cho, J, K.;Jung, Y. R.;Park, W. G.
    • 유체기계공업학회:학술대회논문집
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    • 2001.11a
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    • pp.293-299
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    • 2001
  • Since the previous cut-and-try design algorithm require much cost and time, it has recently been concerned the automatic design technique using the CFD and optimum design algorithm. In this study, the Navier-Stokes equations is solved to consider the more detail viscous flow informations of cascade interaction and O-H multiblock grid system is generated to impose an accurate boundary condition. The cubic-spline interpolation is applied to handle a relative motion of a rotor to the stator. To validate present procedure, the time averaged aerodynamic loads are compared with experiment and good agreement obtained. Once the N-S equations have been solved, the computed aerodynamic loads may be used to computed the sensitivities of the aerodynamic objective function. The Modified Method of feasible Direction(MMFD) is usef to compute the

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IMPLEMENTATION OF IMMERSED BOUNDARY METHOD TO INCOMPRESSIBLE NAVIER-STOKES SOLVER USING SIMPLE ALGORITHM (SIMPLE Algorithm기반의 비압축성 Navier-Stokes Solver와 Immersed Boundary Method)

  • Kim, G.H.;Park, S.O.
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.397-403
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    • 2010
  • The Immersed boundary method(IBM) is one of CFD techniques which can simulate flow field around complex objectives using simple Cartesian grid system. In the previous studies the IBM has mostly been implemented to fractional step method based Navier-Stokes solvers. In these cases, pressure buildup near IB was found to occur when linear interpolation and stadard mass conservation is used and the interpolation scheme became complicated when higher order of interpolation is adopted. In this study, we implement the IBM to an incompressible Navier-Stokes solver which uses SIMPLE algorithm. Bi-linear and quadratic interpolation equations were formulated by using only geometric information of boundary to reconstruct velocities near IB. Flow around 2D circular cylinder at Re=40 and 100 was solved by using these formulations. It was found that the pressure buildup was not observed even when the bi-linear interpolation was adopted. The use of quadratic interpolation made the predicted aerodynamic forces in good agreement with those of previous studies.

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