Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 19 of 19 for “"time-stepping scheme"”.
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Parallel algorithms for direct blood flow simulations
… formulation of Stokes flow. We present new schemes for simulating the three-dimensional hydrodynamic interactions of large number of vesicles with viscosity contrast. The algorithms incorporate a stable time-stepping scheme, high-order spatiotemporal discretizations, spectral …
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Multiphysics modeling and simulation for large-scale integrated circuits
… highly efficient manner, a domain decomposition scheme, parallel computing, and an adaptive time-stepping scheme are incorporated into the proposed multiphysics simulation. Significant reduction in computation time is achieved through the two numerical schemes and the parallel computing with …
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Highly scalable solution of incompressible Navier-Stokes equations using the spectral element method with overlapping grids
… subdomains. The data are either lagged in time or extrapolated to higher-order temporal accuracy using a novel stabilized predictor-corrector algorithm. Matrix stability analysis is used to determine the optimal number of corrector iterations. Stability and accuracy are further improved …
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Efficient tools for the design and simulation of microelectromechanical and microfluidic systems
… of the substrate reduces computation time and memory while increasing the solution accuracy. The results also demonstrate that surprisingly, and unfortunately, even though representing the substrate implicitly has many benefits it does not completely decouple discretization fineness …
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Adaptive stable finite-element methods for the compressible Navier-Stokes equations
… to steady state is reached via a backward Euler time-stepping scheme, and the use of local time-steps allows convergence to be accelerated. The choice of both the nonlinear solver, which is employed to solve the algebraic system arising at each time-step, and the iterative method used within this …
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Sounding Rocket Redesign And Optimization For Payload Expansion And In Flight Telemetry Transmittal
… of the rocket were found via a simple Eulerian time stepping scheme resulting in an estimate of approximately 148,000ft for the four-inch dart. The mechanical loading analysis allowed for the material selection for the rocket components. Reinforced steel fins and carbon fiber tubing, for the …
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Integrated implementation system for pseudodynamic testing
… range options with respect to both control and time integration. The execution routine incorporates both the time integration and control algorithms, and combines these such that they effectively execute as an integrated system. This enables semi-continuous implementation of the pseudodynamic …
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Study of Vortex Ring Dynamics in the Nonlinear Schrödinger Equation Utilizing GPU-Accelerated High-Order Compact Numerical Integrators
… To facilitate this, compact high-order numerical schemes for the spatial derivatives are developed which include a new semi-compact modulus-squared Dirichlet boundary condition. The schemes are combined with a fourth-order Runge-Kutta time-stepping scheme in order to keep the overall method fully …
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Floquet-Wave-Based Analysis of Transient Scattering From Doubly Periodic Structures
… analyzed predominantly using finite difference time domain methods. Unfortunately, for obliquely excited periodic structures, these solvers call for future field values to update current ones, and therefore cannot be applied directly. Several avenues for tackling this problem have been …
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Incorporation of feed-network and circuit modeling into the time-domain finite element analysis of antenna arrays and microwave circuits
… the feed-network and circuit modeling into the time-domain finite element analysis of antenna arrays and microwave circuits. First, simulation of an antenna system requires accurate modeling of interactions between the radiating elements and the associated feeding network. In this work, a feed …
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Modelling and simulation of drying process for ceramic membrane fabrication
… discretization and a backward finite difference time-stepping scheme is employed for time integration. The ability of this improved model is not restricted to a single homogenous layer of hygroscopic and nonhygroscopic material, but on the novelty to incorporate multilayer heterogeneous material …
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Three-dimensional upward scheme for solving the Euler equations on unstructured tetrahedral grids
A new upwind scheme is developed for solving the three-dimensional Euler equations on unstructured tetrahedral meshes. The method yields solution accuracy and efficiency comparable to that currently available from similar structured-grid codes. The key to achieving this result is a novel cell …
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The mathematical modelling and numerical solution of options pricing problems
… second order accurate finite difference scheme is presented, which uses adaptive upwind differences when the mesh Peclet conditions are violated. The resulting tridiagonal system of equations is solved using a direct solver. A careful study of grid refinement displays convergence towards …
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The numerical simulation of thin film flow over heterogeneous substrates
… implicit and has embedded within it an adaptive time-stepping scheme that enables the same to be optimised in a controlled manner subject to a specific error tolerance. Contact lines are ubiquitous in the context of droplet spreading and the wellknown singularity which occurs there is alleviated …
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Numerical Solution of Multiscale Electromagnetic Systems
<p>The Discontinuous Galerkin time domain (DGTD) method is promising in modeling of realistic multiscale electromagnetic systems. This method defines the basic concept for implementing the communication between multiple domains with different scales.</p><p>Constructing a DGTD system consists of …
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Probabilistic finite-difference time-domain simulations using stochastic electromagnetic macro-models
… macro-model in the finite-difference time-domain (FDTD) method. We provide a methodology for the efficient generation and utilization of the stochastic macro-model for the purpose of time-domain analysis in FDTD. The methodology quantifies the impact of uncertainty, manifested as …
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Time-domain second-order wave interactions with floating offshore structures
… on the basis of potential flow theory. A recent time-domain approach is extended to simulate second-order hydrodynamic effects involving large floating structures which cannot be obtained by the conventional linear hydrodynamic theory. The method involves the application of Taylor series …
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Computational modeling and simulation of nonlinear electromagnetic and multiphysics problems
… three-dimensional full-wave methods in the time domain. The problems under consideration fall into two categories. One is nonlinear electromagnetic problems with the nonlinearity embedded in either the permeability or the conductivity of the material's constitutive properties. The other is …
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Particles and Bubbles Collisions Frequency in Homogeneous Turbulence and Applications to Minerals Flotation Machines
… equations of the carrier phase using the same time stepping scheme. In addition to Stokes drag, the pressure gradient in the carrier phase and added-mass forces are also included. The collision model used here allows overlap of particles and bubbles. Collisions kernel, radial relative velocity, …