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.
Results
Showing 1 to 20 of 26 for “"Fluid Equations"”.
-
Entropy Stable Approximations of Nonlinear Conservation Laws and Related Fluid Equations
… Navier-Stokes and two dimensional shallow water equations. To this end, we construct a new family of second-order entropy stable difference schemes which retain the precise entropy decay of the original partial differential equations. Here we employ the entropy conservative differences of …
-
Electrohydrodynamic Simulations of Capsule Deformation Using a Dual Time-Stepping Lattice Boltzmann Scheme
<p>Capsules are fluid-filled, elastic membranes that serve as a useful model for synthetic and biological membranes. One prominent application of capsules is their use in modeling the response of red blood cells to external forces. These models can be used to study the cell’s material properties …
-
Analysis and development of a monolithic computational approach for fluid–structure interaction by means of the finite element method
The phenomenon of fluid–structure interaction (FSI) appears in many engineering applications. Its computation allows to quantify the mechanical behaviour of both fluid and structure interacting with each other. For that purpose, appropriate field equations are specified for an incompressible, …
-
L² decay for weak solutions of the micropolar equations on R³
… decay estimates for solutions of the micropolar fluid equations . Such equations, proposed by A. C. Eringen, generalize the classic model of Navier-Stokes and describe the behavior of fluids with microstructure such as animal blood, liquid crystals, suspensions, among others. For this, we use a …
-
Comparisons of computational methods to represent electron transport in nonequilibrium plasma devices
… In the two-dimensional, time dependent model, fluid equations are solved to obtain the electron and ion densities, and Poisson's equation is solved for the electric potential. These equations can be solved using the local field approximation (LFA), employing conservation equations for the bulk …
-
Nonlinear acoustic pulse propagation in range-dependent underwater environments
… (NPE) is a time-domain formulation of Euler's fluid equations designed to model low angle wave propagation using a wave-following computational domain. The standard formulation consists of four separate mathematical quantities that physically represent refraction, nonlinear steepening, radial …
-
Development of a model for the near-exit plume of a Hall thruster
This thesis presents a fluid model for electron behavior in the near-exit plume of a Hall thruster. The model provides 3D results and allows to study the azimuthal asymmetry induced by the hollow cathode. The model is composed by the charge and energy conservation equations and is intended to solve …
-
Self-similar singularity formation and wellposedness theory for compressible fluids and dispersive PDE
… singularity formation and local wellposedness of fluid equations and dispersive PDE. Regarding singularity formation, we construct radially symmetric smooth selfsimilar profiles for the compressible Euler equations which exhibit an implosion type singularity in finite time. This will be the first …
-
Numerical analysis and visualization of the ionospheric Kelvin-Helmholtz instability
… electrostatic, nonlinear, and time dependent fluid equations that describe the KHI evolution. Spectral and pseudospectral methods are used to solve the spatial dependence of these self-consistent equations. They are chosen over the widely used finite difference technique since spectral methods …
-
Computation of moving interface flows in biophysical applications
… of moving interface problems involving viscous fluids and solid structures. The main computational technique employed in this work is the immersed boundary method, a widely known numerical method for fluid-structure interaction (FSI). In this technique, the fluid equations are solved in an …
-
Fully-kinetic PIC simulations for Hall-effect thrusters
… for electrons and used magnetohydrodynamic fluid equations to model the significant processes. While these codes were computationally efficient, their applicability to non-equilibrated regions of the thruster, such as wall sheaths, was limited, and their accuracy was predicated upon the …
-
Advances in fully-kinetic PIC simulations of near-vacuum Hall thruster and other plasma systems
… for electrons and used magnetohydrodynamic fluid equations to model the significant processes. While these codes were computationally efficient, their applicability to non-equilibrated regions of the thruster, such as wall sheaths, was limited, and their accuracy was predicated upon the …
-
A groupoid approach to geometric mechanics
… variations of a rigid body in an inviscid fluid. The different cases are specified by the properties of the fluid; the fluid may be compressible or incompressible, irrotational or not. By using groupoids we generalize Arnold’s diffeomorphism group framework for fluid flows to show that the …
-
Hybrid-PIC modeling and electrostatic probe survey of Hall thrusters
… was developed. A set of quasi-one-dimensional fluid equations are used for electrons, and a particle-tracking Boltzmann solver is used for the heavy species. The two solutions are linked by charge neutrality. A novel statistical approach to particle creation and tracking is employed which …
-
Development and Application of Hybrid Wray-Agarwal Turbulence Model and Large-Eddy Simulation
… and progress in building blocks of Computational Fluid Dynamics (CFD) technology has made CFD an indispensable tool for modern engineering analysis and design of fluid-based products and systems. For CFD analysis, Reynolds-Averaged Navier-Stokes (RANS) equations are currently the most widely used …
-
Discontinuous Galerkin Studies of Collisional Dynamics in Continuum-Kinetic Plasma
… has been used as the basis for many approximate fluid equations, simulations utilizing the distribution function are relatively uncommon, due primarily to the high dimensionality of the problem. However, advances in numerical methods are steadily making these models more accessible. In this work, …
-
Diagnostics and modelling of an inductively coupled RF low-pressure low-temperature plasma
… the measured plasma density profile, Maxwell's equations and magnetohydrodynamical (MHD) fluid equations are used to calculate the self-consistent electromagnetic field. A number of predictions are presented and compared with experiments. A symmetric, cylindrical inductively coupled discharge …
-
A Runge Kutta Discontinuous Galerkin-Direct Ghost Fluid (RKDG-DGF) Method to Near-field Early-time Underwater Explosion (UNDEX) Simulations
… compressible, inviscid and adiabatic flow, the fluid flow is governed by a set of Euler fluid equations. In practical simulations, we often encounter computational difficulties that include large displacements, shocks, multi-fluid flows with cavitation, spurious waves reflecting from boundaries …
-
Flashing flow of refrigerant HFC-134a through a diabatic capillary tube
… was described by four governing differential equations and boundary conditions. The numerical model for the two-phase flow region used one-dimensional nonequilibrium two-fluid equations which accounted for the relative velocity and the temperature difference between the vapor and liquid …
-
Temperature Effects on the Behavior of Liquid Hydrogen Isotopes Inside a Spherical-Shell Inertial Confinement Fusion Target
… kept uniform dynamically: there are continuous fluid flows in the regions of the vapor and liquid. The characteristics of the fluid flows are obtained by solving the fluid equations under the low-Reynolds-number approximations. The effect of the component separation both in the liquid layer and …
Page 1 of 2