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Showing 1 to 20 of 23 for “"Grid Refinement"”.
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Application of r-Adaptation Techniques for Discretization Error Improvement in CFD
… error can be reduced through uniform grid refinement but is often impractical for typical engineering problems. Grid adaptation provides an efficient means for improving solution accuracy without the exponential increase in computational time associated with uniform grid refinement. …
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Numerical models of Hall thruster ionization oscillations
… electron injection region, ion time step size, grid refinement, heavy particle mass reduction, and an artificial permittivity factor. These studies help to determine the parameters that will produce accurate simulations in the future, and identify the parts of the model that need improvement. …
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Modeling Mesoscale Eddies: the Effects of Resolution onOcean Turbulence
… Using the ocean model Oceananigans, we perform a grid refinement study to determine the minimal resolution required to represent mesoscale eddies in the primitive equations. Convergence is evaluated through several metrics, including surface and depth-integrated kinetic energy, spectra, and …
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A high-order discontinuous Galerkin multigrid solver for aerodynamic applications
… Galerkin finite element solver using p-multigrid with line Jacobi smoothing. The line smoothing algorithm is presented for unstructured meshes, and p-multigrid is outlined for the nonlinear Euler equations of gas dynamics. Analysis of 2-D advection shows the improved performance of line …
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Effect of surface imperfections on the stability of compressible laminar boundary layers
… presented include the effect of computational grid refinement, geometrical parametres such as heights and slopes of steps, Mach number and Reynolds number on the mean flow as well as the stability characteristics. A proper grid should be chosen to predict accurately the mean flow profiles, …
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Numerical study of linearized unsteady stagnation flow
… stagnation flows. The two methods are tested for grid refinement, and results obtained using the three-dimensional method are compared with those from the two-dimensional method. As expected, it is found that three-dimensional disturbances decay at a faster rate than two-dimensional ones.</p>
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Exploring a Novel Adaptive Mesh Refinement Strategy for High-Speed CFD
<p>Adaptive Mesh Refinement (AMR) techniques to efficiently and robustly achieve grid independent solutions on multi-element unstructured grids is a topic of practical interest within the CFD community.</p> <p>The current effort focuses on the efficiency of a novel Adaptive Mesh Refinement (AMR) …
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Multigrid solution for high-order discontinuous Galerkin discretizations of the compressible Navier-Stokes equations
… finite element discretization and p-multigrid solution procedure for the compressible Navier-Stokes equations are presented. The discretization has an element-compact stencil such that only elements sharing a face are coupled, regardless of the solution space. This limited coupling …
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A numerical method for systems of ordinary differential equations
… modified quasilinearization algorithm, with a grid refinement algorithm introduced into the solution procedure. The ability to find a general solution to systems of ordinary differential equations, also puts in a new light the question of solving partial differential equations via the method of …
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Finite element analysis of flows in secondary settling tanks
… also possible to realise an unstructured grid within the FVM, the power of the finite element method (FEM) lies in its higher flexibility in fitting irregular domains and in providing local grid refinement. Generally, unstructured mesh procedures with the FVM require essential, additional …
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Analysis of Bridge Deck Sections by Pseudo-compressibility method based on FDM and LES: Improving Performance through Implementation of Parallel Computing
… simulations on a single computer. Minimum grid refinement to adequately resolve the boundary layer is identified. A user manual is developed so that the program can be operated by a designer with minimal training. Finally, the model is validated by comparing the force coefficients that it …
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Improving shock-capturing robustness for higher-order finite element solvers
… which can pollute the solution accuracy. Grid adaptation, along with shock-capturing methods such as artificial viscosity, can be used to resolve the shock by targeting the key flow features for grid refinement. This is a powerful tool, but cannot proceed without first converging on an …
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New methods for sensitivity analysis of chaotic dynamical systems
… aerodynamic shape optimization and adaptive grid refinement. However, traditional sensitivity analysis methods break down when applied to long-time averaged quantities in chaotic dynamical systems, such as those obtained from high-fidelity turbulence simulations. Also, a number of dynamical …
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The numerical analysis of turbulent flow around off-shore structures
… The prediction procedure was first tested for grid refinement and optimum solution domain size until profiles at several locations for selected variables showed little change with further increase of domain size and grid points. The effect of different wind directions was investigated for the …
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Anisotropic output-based adaptation with tetrahedral cut cells for compressible flows
… adaptation on complex bodies. Through grid refinement studies on inviscid flows, this cut-cell discretization is shown to produce similar accuracy as boundary-conforming meshes with a small increase in the degrees of freedom. The cut-cell discretization is then combined with …
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Sparsity based methods for target localization in multi-sensor radar
… false alarm and the probability of detection. A grid refinement procedure is also proposed to eliminate the need for a dense grid which would increase the computational complexity significantly. Expressions for the computational complexity of the proposed CFAR detectors are derived. It is shown …
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Numerical Prediction of the Interference Drag of a Streamlined Strut Intersecting a Surface in Transonic Flow
… Accurate drag prediction requires a very fine grid and this leads to problems associated with the grid generator. Several challenges facing the unstructured grid methodology are discussed: slivers, grid refinement near the leading edge and at the trailing edge, grid convergence studies, volume …
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Development of a Multifluid Magnetohydrodynamic Model for Anisotropic, Partially Ionized Plasmas
… solutions in the literature. Results of grid refinement and parametric studies for the GEM case are also described. The proposed multifluid MHD model is shown to recover known published results with relatively small computational effort and the potential of the proposed treatment for …
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Computational modeling of wind turbine wake interactions
… (LES) with a dynamic Smagorinsky-Lilly sub-grid scale (SGS) model. The simulations showed the grid refinement to be inadequate for LES studies. The RANS closure schemes did not indicate a dominant model. However, relevant literature on separating flows has shown the k-ω SST model to be …
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The mathematical modelling and numerical solution of options pricing problems
… of interest where accuracy is most desired, and grid coarsening where there is least interest. These transformations are shown to be effective in producing accurate solutions on modest computational grids. The spatial discretisation strategy is chosen to meet accuracy requirements as sell as to …
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