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Showing 1 to 20 of 24 for “"convection dominated"”.
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Reduced order modeling of convection-dominated flows, dimensionality reduction and stabilization
… methodologies for reduced order modeling of convection dominated flows. Accordingly, three main problems are addressed. Firstly, an optimal manifold is realized to enhance reducibility of convection dominated flows. We design a low-rank auto-encoder to specifically reduce the dimensionality …
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A posteriori error estimates and adaptive methods for convection dominated transport processes
… <br>for finite volume approximations of convection dominated nonlinear <br>transport problems. <br>Robustness means that the error estimates are uniform with respect to <br>vanishing diffusion coefficients. <br>The a posteriori error estimates give upper bounds for the error in the …
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Filter Based Stabilization Methods for Reduced Order Models of Convection-Dominated Systems
… simulations of unsteady, nonlinear, convection-dominated systems. The new ROMs proposed are variable delta filtering applied to the evolve-filter-relax ROM (V-EFR ROM), variable delta filtering applied to the Leray ROM, and approximate deconvolution Leray ROM (ADL-ROM). They are …
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Simulation of steady mixed convection in a lid-driven cavity filled with newtonian fluid by finite volume method
The steady mixed convection flow in a lid-driven cavity was simulated. The cavity was filled with a Newtonian fluid, both vertical walls are adiabatic, while the horizontal walls were either fixed cold and uniformly/oscillatory heated. Firstly, the effect of internal heat generation or absorption …
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Parallel Domain Decomposition Preconditioning for the Adaptive Finite Element Solution of Elliptic Problems in Three Dimensions
… symmetric problems but also for nonsymmetric and convection-dominated elliptic problems. This generalization, in the absence of theoretical or mathematical background, is based on empirical observations. Moreover, it turns out to be more effective and robust than the original symmetric …
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Layer-averaged modeling of turbidity currents with a finite element method
… yields spurious oscillations when applied to convection-dominated flows, the dissipative-Galerkin technique which has a selective damping property, is used. In order to track the moving front numerically, a node-adding method is used for the one-dimensional problem of channelized turbidity …
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Stabilization of POD-ROMs
… orthogonal decomposition) for both the CDR (convection-diffusion-reaction) equation and the NSEs (Navier-Stokes equations). Stabilization is necessary because standard POD-ROMs of convection-dominated problems usually display numerical instabilities. The first stabilized ROM investigated is a …
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A-Posteriori bounds on linear functionals of coercive 2nd order PDEs using discontinuous Galerkin methods
… finite element method. For equations such as the convection-diffusion equation, the convection term is handled by the standard DG method for hyperbolic problems while the diffusion operator is discretized by the LDG scheme. This choice allows for the effective bounding of outputs associated with …
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Multigrid solutions of elliptic fluid flow problems
… for the accurate and economic simulation of convection dominated flows. The use of a high-order approximation to the convective transport terms found in the governing equations of motion has been investigated in conjunction with an unsegregated smoothing technique. Results are presented for a …
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Covolume-Upwind Finite Volume Approximations For Linear Elliptic Partial Differential Equations
… To avoid non-physical numerical oscillations for convection-dominated problems, nonstandard control volumes (covolumes) are generated based on local Peclet's numbers and the upwind principle for the finite volume approximations. Two types of discretization schemes with mass lumping are developed, …
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Heat Transfer Characterization in Jet Flames Impinging on Flat Plates
… least squares linear curve fitting through the convection dominated region of net heat flux data and was validated by experimental measurements with an aspirated thermocouple. For low axial distances (H/d =3.3), the gas temperature dropped by only 15 % from r/d = 0 to r/d = 2. Total heat flux …
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Layer-adapted meshes for convection-diffusion problems
… perturbation problems - in particular stationary convection-dominated convection-diffusion problems. More precisely it is devoted to the construction and analysis of layer-adapted meshes underlying these numerical methods. An early important contribution towards the optimization of numerical …
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Numerical Study of Nutrient Mixing in Trabecular Bone in Microgravity, Disuse and Normogravity
… occurs in two stages: an initial diffusion-dominated rapid mixing phase followed by a convection-driven slow decay phase as oscillatory flow structures develop. Increasing frequency enhances convective transport, reduces mixing time, and elevates wall shear stress into the osteogenic range. …
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Finite Element Simulation of Interfacial Flows on Unstructured Meshes using a Second-order Accurate VOF Method
… Petrov-Galerkin (SUPG) stabilization is used for convection-dominated flows. Fluid interfaces are reconstructed and advected using a second-order accurate VOF method. An accurate least-squares circle-fit technique has been developed for curvature calculation on triangular meshes, and then used to …
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Domain decomposition preconditioners for higher-order discontinuous Galerkin discretizations
… preconditioner is extended to the solution of convection-dominated problems using a Robin-Robin interface condition. An inexact BDDC preconditioner is developed based on incomplete factorizations and a p-multigrid type coarse grid correction. It is shown that the incomplete factorization of the …
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Design of Latent Thermal Energy Storage Systems
… melting where the heat transfer is convection dominated, unlike in chapter 3 and 4 where the melting is ruled by pure conduction. In accord with constructal design, the search is for effective heat-flow architectures. The volume-constrained improvement of the designs for heat flow …
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Hydrodynamic and Magnetohydrodynamic Convection in Accretion Disks
The prevalence and consequences of convection perpendicular to the plane of accretion disks have been discussed for several decades. Recent simulations combining convection and the magnetorotational instability have given fresh impetus to the debate, as the interplay of the two processes can …
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Reduced-Order Modeling of Complex Engineering and Geophysical Flows: Analysis and Computations
… reduced-order modeling of structurally dominated turbulent flows: the dynamic subgrid-scale model and the variational multiscale model. These models, which are considered state-of-the-art in large eddy simulation, are carefully derived and numerically investigated. Since modern closure …
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