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 73 for “"quasi-steady state"”.
-
Development of On-The-Fly Quasi-Steady State Approximation for Chemical Kinetics in CFD
… study analyzes the feasibility of On-The-Fly Quasi-Steady-State Approximation (OTF-QSSA) application for solving chemical kinetics within Computational Fluid Dynamics (CFD) simulations, aiming to reduce the computational demand of detailed mechanisms. An algorithm that dynamically identifies …
-
Prediction of departure from nucleate boiling in PWR fast power transients
… differences in predicted results between use of steady state versus transient Departure from Nucleate Boiling (DNB) models, for fast power transients under forced convective heat exchange conditions. Theoretical DNB models based on liquid film thickness variation are adapted and modified from …
-
Welding Simulations of Aluminum Alloy Joints by Finite Element Analysis
… on the thermal history. The residual stress state from a three-dimensional analysis of the butt joint is compared to previously published results. For the quasi-steady state analysis the maximum residual longitudinal normal stress was within 3.6% of published data, and for a fully transient …
-
Improved Underwater Vehicle Control and Maneuvering Analysis with Computational Fluid Dynamics Simulations
The quasi-steady state-space models generally used to simulate the dynamics of underwater vehicles perform well in most steady flow scenarios, and are therefore acceptable for modeling today\'s fleet of endurance-focused autonomous underwater vehicles (AUVs). However, with their usage of numerous …
-
Oscillating Field Current Drive in the Reversed Field Pinch
… originally proposed as a means of maintaining a quasi steady-state plasma current in a RFP without building up the magnetizing flux threading the central hole of the torus. The MHD dynamics of OFCD is analyzed using a combination of a 1-D transport code, a linear resistive MHD stability model, …
-
A study of the effects of linear networks on FM waves
… is investigated by the Fourier method and the Quasi-steady-state method. The major enphasis is placed on the Fourier method, and extensive digital computer programs are developed to allow this method to be implemented on the modern, high-speed digital computer. In the Fourier method, the …
-
A numerical method for electro-kinetic flow with deformable interfaces
… boundary problem. We present solutions for the quasi-steady state problem with [psi] = O(1) and solutions for the time dependent problem with [psi] [netsted less less] 1, where [psi] is the dimensionless surface potential. Leading order problems for both electric fields and fluid fields are …
-
High current pulse characterization of semiconductor devices
… allows for capture of both the transient and quasi-steady-state responses, in the context of a single measurement. EETLP provides unprecedented insight into the turn-off dynamics of snapback-type devices. Device measurement data are presented to demonstrate the capabilities of EETLP.
-
Quasistationarität und fast-invariante Mengen gewöhnlicher Differentialgleichungen
… the present paper is to analyse the concept of quasi-stationarity, which is motivated from bio-chemistry, and to investigate it from a matematical perspective. In Chapter 1 the concept of quasi-stationarity is presented in the context of chemical reactions. Examples, particularly the …
-
Experimental and Modeling Studies of the Stability of Pitting Corrosion on Pure Aluminum in Basic Chloride Solutions
The quasi steady state model was expanded to include homogeneous bulk reactions for hydrolysis and complexation reactions. The model predicted pH values of 2.5 to 3.0, values that agreed well with experimental measurements, only when the first two hydrolysis reactions of aluminum were included in …
-
The response of ocean salinity patterns to climate change : implications for circulation
… the sea surface and the atmosphere. For a quasi-steady state system, these surface fluxes are balanced by compensating transports of salt in the ocean interior. In a warming climate, the atmosphere holds additional water vapor which acts to intensify the global water cycle. Amplified …
-
The plasma focus as a thruster
… take the DPF. The effect of pulsed compared to quasi-steady state operation is computed. There is no known experimental data regarding thrust measurements for any DPF, so the thrust is analytically calculated using experimental data for the TAMU DPF. The calculated thrust is slightly higher than …
-
AeroDima: a cheetah-inspired aerodynamic tail for rapid manoeuvrability
… a cheetah's tail in a wind tunnel to develop a quasi-steady state model. A bio-inspired aerodynamic tail was then designed to maximise drag forces. This bio-inspired tail was also studied in a wind tunnel and compared to the cheetah tail's model. The tail required a platform to operate on, so …
-
Control of servers in a two node queueing network
… been studied; the first problem is to find a quasi-steady-state control policy for a periodic review of server allocation. This policy can be regarded as a feedback control policy to adapt the network parameter changes by changing the number of servers at each node.The second problem (main …
-
Stochastic Simulation Methods for Biochemical Systems with Multi-state and Multi-scale Features
… The thesis is focused on systems with multi-state and multi-scale features and divided into two parts. In the first part, we propose new algorithms that improve existing multi-state simulation methods. We first compare the well known Gillespie\\\'s stochastic simulation algorithm (SSA) with …
-
Virtual Planar Motion Mechanism Testing of 8:1 Spheroids
… and accelerations. This makes it possible to use quasi-steady state models with terms independent of both velocity and acceleration. This paper explores the ability of simple damping models (solely a function of velocity) with added mass terms (solely a function of acceleration) to simulate the …
-
Decadal variability of the subtropical gyre and deep meridional overturning circulation of the Indian Ocean
… (iii) the influence of diapycnal diffusivity on quasi-steady MOC states.<br/>The decadal variability of the subtropical gyre transport over the ocean interior (away from boundary currents) is investigated using hydrographic data from 32°S. Estimates of the relative gyre transports are: 41 ± 5.1 …
-
Sunspaces for passive building heating: calculation models and utilization of empirical data
… Particular attention is given to the quasi-steady-state methods, which are the most used by the designers. The thesis critically analyses calculation methods, identifies their problematic aspects and provides some indications to improve the method of the technical standard EN ISO …
-
Modeling and simulation of coronary stents: Intravascular drug delivery and arterial drug distribution
… spatially-averaged drug levels in the wall at quasi-steady state are discussed. Anisotropic drug diffusivities result in similar average drug levels in the arterial wall but very different spatial distributions. Higher circumferential vascular diffusivity results in more uniform drug loading in …
-
Friction models in the solution of nonstationary contact problems
… element program ABAQUS. The new models are: a quasi-steady-state sliding model proposed by Zhang, Moslehy and Rice; a nonlinear pressure-dependent model proposed by Wriggers, vu Van and Stein; and a model that includes a film of lubricant proposed by Wilson, Hsu and Huang. The friction models …
Page 1 of 4