Search for dissertations about: "Harmonic Balance"

Showing result 1 - 5 of 25 swedish dissertations containing the words Harmonic Balance.

2. 1. 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

4. 2. Nonlinear transistor models for microwave and millimeterwave circuits

   Author : Lars Bengtsson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; non-linear model; MESFET; volterra series; HBT; nonlinear simulation; HEMT; BJT; HFET; physical model; power spectrum measurement; harmonic balance;

   Abstract : .... READ MORE

5. 3. Methods for Simulation and Characterization of Nonlinear Mechanical Structures

   Author : Martin Magnevall; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear dynamics; nonlinear parameter estimation; harmonic balance; reverse-path; zero-memory nonlinear systems; hysteretic nonlinearities; dry-friction; geometric nonlinearities;

   Abstract : Trial and error and the use of highly time-consuming methods are often necessary for modeling, simulating and characterizing nonlinear dynamical systems. However, for the rather common special case when a nonlinear system has linear relations between many of its degrees of freedom there are particularly interesting opportunities for more efficient approaches. READ MORE

6. 4. 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

7. 5. 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