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Showing 1 to 20 of 807 for “"Navier-Stokes"”.
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Analysis of the Navier--Stokes-αβ equations
… we prove various analytic results for the Navier--Stokes-αβ equations. We establish well-posedness and regularity. In addition we determine estimates for the nodal distance and the number of determining modes. A method of averaging is developed and applied to derive a Kaman--Howarth type …
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The Navier-Stokes equations for elliptic quasicomplexes
The classical Navier-Stokes equations of hydrodynamics are usually written in terms of vector analysis. More promising is the formulation of these equations in the language of differential forms of degree one. In this way the study of Navier-Stokes equations includes the analysis of the de Rham …
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Generalized Navier-Stokes equations for active turbulence
… This approach generalizes the incompressible Navier-Stokes equations by accounting for active stresses through a linear instability mechanism, in contrast to externally driven classical turbulence. This minimal model can reproduce experimentally observed velocity statistics and is analytically …
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Stabilized finite elements for compressible turbulent Navier-Stokes
… turbulent flows. The Reynolds averaged Navier-Stokes (RANS) equations and modified Spalart-Almaras (SA) turbulence model are discretized using the streamline/upwind Petrov-Galerkin (SUPG) scheme. A fully implicit methodology is used to obtain steady state solutions or to drive unsteady …
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A Class of Stable, Efficient Navier-Stokes Solvers
We study a class of numerical schemes for Navier-Stokes equations (NSE) or Stokes equations (SE) for incompressible fluids in a bounded domain with given boundary value of velocity. The incompressibility constraint and non-slip boundary condition have made this problem very challenging. Their …
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Backward stochastic Navier-Stokes equations in two dimensions
… is also established. The backward stochastic Navier-Stokes equations (BSNSEs, for short) corresponding to incompressible fluid flow in a bounded domain $G$ are studied in the second part. Suitable a priori estimates for adapted solutions of the BSNSEs are obtained which reveal a surprising …
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Hilbert Space Projections and the Navier-Stokes Equation
Unfortunately, but not surprisingly, there arises a closure difficulty: the reduced set of physically admissible measures is still large. In this thesis a particular subclass of admissible measures is studied using the physically based theory of high field sensitivity. The projection associated …
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Operator splitting methods for the Navier-Stokes equations
… for the solution of the incompressible Navier-Stokes equations are examined. These algorithms are representative of the two prevalent splitting philosophies used to split the Navier-Stokes equations. The properties of the algorithms are determined by Fourier analysis of a model problem. …
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Exponential Integrators for the Incompressible Navier-Stokes Equations
… for time integration of the incompressible Navier-Stokes equations (NSE). The method is based on a projection onto the subspace of divergence-free (incompressible) functions interleaved with a Krylov-based exponential time integration (KBEI). These time integration methods provide a high …
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A parabolized Navier-Stokes method for wind farm applications
… ones for operational purposes. Conventional Navier-Stokes simulations (commonly referred to as CFD simulations) are computationally very expensive since they require a supercomputer with runtimes of several weeks. A Parabolized Navier-Stokes (PNS) method is developed and implemented in this …
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Solution Acceleration and Accuracy Improvements for Navier-Stokes Solvers
There are two competing goals in computational fluid dynamics: high solution accuracy, and low computational cost. In the present research, three major tasks were performed to improve the solution accuracy and increase the convergence of steady-state solutions: (1) investigate the sources of …
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Simulation of time-dependent free surface Navier-Stokes flows
… for simulation of time-dependent free-surface Navier-Stokes flows are developed. Both techniques are based on semi-implicit time advancement of the momentum equations, integral formulation of the spatial problem at each timestep, and spectral-element discretization to solve the resulting …
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Laser engine simulation using pressure based navier-stokes solver
… Based on this procedure, a Pressure Based Navier-Stokes Solver (PBNS) is developed using a generalized curvilinear coordinate system. The solver is first tested in application to a subsonic compressible flow over an insulated flat plate and to a flow in an axisymmetric converging-diverging …
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Numerical Navier-Stokes solutions of supersonic slot injection problems
… relaxation applied to the thin layer Navier-Stokes equations. To test the accuracy of the numerical methods without the complications and uncertainties of turbulence modeling, two sample cases were chosen with laminar flows. The sample problems were the compressible laminar boundary …
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Preconditioned conjugate gradient methods for the Navier-Stokes equations
… of the unsteady, two-dimensional, compressible Navier-Stokes equations of fluid flow. The Navier-Stokes equations are cast in an implicit, upwind finite-volume, flux split formulation. Preconditioning techniques are employed with the Conjugate Gradient like method to enhance the stability and …
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Investigation of finite element schemes for the Navier Stokes equations
… method got the solution of the two-dimensional Navier-Stokes equations. The numerical method to be used was the finite element method. A literature survey revealed that a limitation common to all finite element methods available to date is that they only produce solutions for low Reynold's …
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Boundary integral/spectral element solution of the Navier-Stokes equations
… technique was developed to solve the unsteady Navier-Stokes equations and the steady convective transport equation. A semi-implicit formulation of the temporal integration rendered a linear spatial problem at sequential time increments. For low to moderate Reynolds number flows, time stepping …
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A Perfectly Matched Layer Method for the Navier-Stokes equations
… desirable. Here, the method is extended to the Navier-Stokes equations, and is implemented with a high-order discontinuous Galerkin finite element method (DGFEM). The weaknesses and strengths of the method are investigated, and its performance is assessed when applied to complex flows; in …
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