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Showing 1 to 20 of 31 for “"Operator splitting"”.
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Operator splitting methods for the Navier-Stokes equations
… 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. It is shown that splittings resulting in Stokes subproblems have desirable dissipative …
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Finite Horizon Optimality and Operator Splitting in Model Reduction of Large-Scale Dynamical System
… optimal with respect to the output. Thus, we use operator splitting to integrate the best features of system theoretic approaches with trajectory based methods such as POD in order to mitigate the effect of the control inputs for the approximation of nonlinear dynamical systems. We reduce the …
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Development of stable operator splitting numerical algorithms for phase-field modeling and surface diffusion applications
… were approached by different methods using operator splitting techniques found in previous literature. In addition, dewetting of gold films due to surface diffusion was modeled to present the extendability and efficiency of the spectral methods derived. The simulations developed are relevant …
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Stable algorithms for generalized thermoelasticity based on operator-splitting and time-discontinuous Galerkin finite element methods
… time-stepping algorithm is proposed based on operator-splitting and the time-discontinuous Galerkin finite element method for the non-classical, linear thermoelastic model. The coupled problem is split into two contractive sub-problems, namely, the mechanical phase and thermal phase, on the …
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Existence and Uniqueness of the Solution of a Traffic Flow Partial Differential Equation on Multi-Lane Freeways
… of cars on a multi-lane freeway using the operator splitting method. Furthermore, we shall prove the uniqueness of the solution of the stochastic differential equation which forms when we apply the operator splitting method to the traffic flow stochastic partial differential equation.</p>
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Stochastic Volatility with Levy Processes: Calibration and Pricing
… technique to different parts of the system. An operator splitting method is proposed to break down the complicated problem into a diffusion part and a jump part. The two parts are treated with a finite difference and a finite element method, respectively. For the PIDEs in 1-D, 2-D and 3-D cases, …
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Numerical Solution Techniques for Reaction Parameter Sensitivity Coefficients in Multicomponent Subsurface Transport Models
… system of sensitivity equations to applying the operator splitting approach to solve the sensitivity equations. Codes are also developed to compare the direct and adjoint methods of calculating reaction parameter sensitivity coefficients in batch and transport problems. CPU time comparisons for …
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Modeling the biodegradation kinetics of dissolved organic contaminants in a heterogeneous two-dimensional aquifer
… in a two-dimensional heterogeneous aquifer. Operator splitting, which involves splitting the transport and kinetic equations and solving each with an appropriate method, was the numerical technique chosen because of the ease at which different biodegradation kinetic models can be changed. The …
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Explicit, Multi-Map Symplectic Integrator for Three -Body Classical Trajectory Studies in Hyperspherical Coordinates
… long integration times. There is a general operator splitting method for developing explicit symplectic integration algorithms to any arbitrary even order for separable Hamiltonians where the position and momentum coordinates are uncoupled. Explicit symplectic integrators for general …
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Explicit, multi-map symplectic integrator for three-body classical trajectory studies in hyperspherical coordinates
… long integration times. There is a general operator splitting method for developing explicit symplectic integration algorithms to any arbitrary even order for separable Hamiltonians where the position and momentum coordinates are uncoupled. Explicit symplectic integrators for general …
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Investigation of bond graphs for nuclear reactor simulations
… multiphysics transients in nuclear reactors is operator splitting, which treats the single physics individually and exchanges the information at every time step. This approach has limited accuracy, and so there is interest in the development of methods for fully coupled physics simulation. The …
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Diskretisierungsverfahren für Systeme von Konvektions-Diffusions-Dispersions-Reaktions-Gleichungen und Anwendungen
… zweiter Ordnung. Die Gleichungen werden über das Operator-Splitting-Verfahren miteinander gekoppelt. Die numerischen Methoden wurden in ein umfangreiches Programmpaket R3T (radionuclude-reaction-retardation and transport) programmiert, das für ein Projekt zur Simulation von Transport-Prozessen …
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Modeling coupled physics and biology in ocean straits
… model is created on a structured grid using operator splitting and masking. This model is able to accurately represent biology for various physical flows, including advection-dominated flows over discontinuities, by using the Weighted Essentially Non-Oscillatory (WENO) scheme. The numerical …
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Numerical methods for weather derivatives pricing
… nonstandard finite difference combined with the operator splitting approaches, are proposed. The methods are effective on handling with convection dominant condition and preserve the positivity. The positivity and stability conditions are established and the numerical solutions are simulated. …
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Anisotropic variational models and PDEs for inverse imaging problems
… equation, based on alternate directions and operator splitting techniques. We study their scale-space properties and show their efficiency in processing large images. Moreover, we generalise the osmosis equation to accommodate suitable directional information: this modification turns out to …
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Multiscale simulation of viscoelastic flows : applications to kinetic theory models of polymer melts and liquid crystalline polymers
… theory. The numerical approach is based on an operator splitting time integration method that decouples the calculation of microstructure by solution of a hyperbolic diffusion equation from the velocity and pressure field evolution, which is obtained by solution of a generalized Stokes problem. …
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Discontinuous Galerkin solutions of the Boltzmann equation: spectral collocation and moment methods
… form. The equations are typically solved with operator splitting and low-order methods. We examine the promise and challenges of applying a high-order DG method with explicit Runge-Kutta time-stepping to these equations on common 1D test cases. The thesis ends with a discussion on the prospects …
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The development of a predictive procedure for localised three dimensional river flows
… facing step. The equations are solved by an operator splitting method which, it is argued, allows for an accurate and realistic treatment of the troublesome advection terms at low spatial resolutions. This is thought to be essential since for three dimensional problems owing to computer time …
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A Unified Framework for Simulating Impact-Induced Detonation of a Combustible Material in an Elasto-Plastic Confiner
… of continuum mechanics, along with a new set of operator-splitting-based numerical solvers to allow for the efficient solution of the problems that it is put to, and a new Riemann ghost fluid method for accurate simulation of material interfaces. In addition to this work, novel mathematical …
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Micro-physical modeling of aircraft exhaust plumes and condensation Trails
… of the plume are solved simultaneously using an operator splitting method. The plume model is used to quantify how the in-plume chemical composition is affected in response to various environmental conditions and different engine and/or fuel characteristics. Results demonstrate that an instant …
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