Search for dissertations about: "Nonlinear Acoustics"

Showing result 1 - 5 of 47 swedish dissertations containing the words Nonlinear Acoustics.

  2. 1. Nonlinear Acoustics Applied to NonDestructive Testing

    Author : Kristian Haller; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear acoustics; nondestructive testing; activation density; slow dynamics; resonance frequency; nonlinear wave modulation spectroscopy; harmonic generation; trapped modes; open resonator; sweep rate;

    Abstract : Sensitive nonlinear acoustic methods are suitable for material characterization. This thesis describes three nonlinear acoustic methods that are proven useful for detection of defects like cracks and delaminations in solids. READ MORE

  4. 2. Turbomachinery Aeroacoustic Calculations using Nonlinear Methods

    Author : Martin Olausson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nonlinear; CFD; Time Spectral; CAA; Ffowcs-Williams Hawkings; Broadband; Time lag; Computational Aeroacoustics; Fan-Noise; Rotor-Stator interaction; Buffer layer; Oscillating sphere; Newton-GMRES; Computational Fluid Dynamics; Acoustic analogies; Sponge; Counter-Rotating Propfan; Harmonic Balance Technique; Tone; FWH; Chorochronic periodicity; Hybrid RANS LES;

    Abstract : Noise regulations for aircraft that fly over populated areas are becoming continuously stricter. This in combination with increasing computational capabilities has boosted interest in aeroacoustic computations in the aerospace industry. READ MORE

  5. 3. Transient Electromagnetic Waves in Nonlinear Media

    Author : Daniel Sjöberg; Institutionen för elektro- och informationsteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signal processing; nonlinear materials; Electromagnetic waves; instantaneous response; waveguides; shock waves; entropy condition; Elektronik och elektroteknik; Electronics and Electrical technology; Signalbehandling; Electromagnetism; optics; acoustics; Elektromagnetism; optik; akustik;

    Abstract : This thesis is concerned with the propagation of transient electromagnetic waves in nonlinear media. It consists of a General Introduction and five scientific papers. The General Introduction gives a broad overview of nonlinear electromagnetic phenomena. READ MORE

  6. 4. Nonlinear Interaction Between Ultrasonic Waves and Cracks and Interfaces

    Author : Milan Poznic; Leif Kari; Bruce Drinkwater; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ultrasonic waves; crack; modulation; rough interface; partially closed; surface-breaking; fluid-filled; Acoustics; Akustik;

    Abstract : The subject of this thesis is the development of new ultrasound inspection techniques for detection of cracks that are smaller than the wavelength of the inspecting wave and the characterization of cracks in fluid-filled pipes as either surface-breaking or subsurface. The spectrum of the scattered field of a partially closed crack comprises harmonic components not expected to be found in the case of linear scatterers such as pores or inclusions. READ MORE

  7. 5. Interaction between ultrasonic waves and nonlinear cracks and interfaces

    Author : Milan Poznic; Claudio Pecorari; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustics; Akustik;

    Abstract : .... READ MORE