Search for dissertations about: "harmonic balance analysis."

Showing result 1 - 5 of 14 swedish dissertations containing the words harmonic balance analysis..

2. 1. Control and Analysis of Pulse-Modulated Systems

   Author : Stefan Almér; Ulf Jönsson; Gilead Tadmor; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Pulse-width modulation; Periodic systems; Stability analysis; Harmonic analysis; Lyapunov methods; Dynamic phasors; Harmonic transfer function; Switched mode power converters; Sampled data modeling; H-infinity synthesis; Optimization; systems theory; Optimeringslära; systemteori;

   Abstract : The thesis consists of an introduction and four appended papers. In the introduction we give an overview of pulse-modulated systems and provide a few examples of such systems. Furthermore, we introduce the so-called dynamic phasor model which is used as a basis for analysis in two of the appended papers. READ MORE

4. 2. Numerical Methods for Aeroacoustic Analysis of Turbomachines

   Author : Daniel Lindblad; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Stability Analysis; Acoustic Analogy; Tonal Noise; Nonreflecting Boundary Conditions; Duct Modes; Turbomachinery; Harmonic Balance; Ffowcs Williams - Hawkings; Time Sampling; Aliasing;

   Abstract : Numerical simulations are important tools for developing new aircraft that can meet future needs. When numerical simulations are used to compute aircraft noise, a two-step procedure is often employed. In the first step, the noise sources are determined using, e.g. READ MORE

5. 3. Numerical Methods for Aeroacoustic Analysis of Turbomachinery

   Author : Daniel Lindblad; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Convective Ffowcs Williams - Hawkings Equation; Computational Aeroacoustics; Acoustic Analogy; Von Neumann Stability Analysis; Tonal Noise; CAA; Harmonic Balance Method; Counter Rotating Open Rotor;

   Abstract : Air transportation is today an integral part of many peoples life and it continuously grow to serve more of us in new and ingenious ways. There are however negative sides to this growth as well, such as increased noise around airports and more CO2 emissions, which must be addressed if aviation is to be part of a sustainable future. READ MORE

6. 4. Hybrid and Dynamic Substructuring Methods for Energy Flow Analysis

   Author : Anders Wilson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fractional derivatives; structural modeling; mid-frequency; finite element method FEM; vibro-acoustics; statistical energy analysis SEA; dynamic substructuring; hybrid analysis; viscoelasticity;

   Abstract : Modeling techniques and solution tools to analyze the dynamic and vibro-acoustic behavior of complex built-up structures are matters of increasing interest, especially for thin walled structures as in transportation vehicles, such as automobiles, trucks, trains and aircraft. In structures like these, the reduction of cost, weight, sound and vibration levels are primary issues for research and development. READ MORE

7. 5. Fabrication, Characterisation and Modelling of Subharmonic Graphene FET Mixers

   Author : Omid Habibpour; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gate dielectric; Graphene; harmonic balance analysis.; subharmonic resistive mixers; microwave FETs; device modelling;

   Abstract : Graphene has exceptional carrier transport properties which makes it a promising material for future nanoelectronics. The high carrier mobility along with the ability to switch between n- and p-channel in a graphene field effect transistor (G-FET) truly distinguishes it from other types of FET technologies and enables completely new high frequency devices. READ MORE