Sökning: "Plane wave expansion method"
Visar resultat 1 - 5 av 10 avhandlingar innehållade orden Plane wave expansion method.
1. Methods and techniques for precise and accurate in-duct aero-acoustic measurements : Application to the area expansion
Sammanfattning : During the design and commissioning of combustion equipment, combustion associated instabilities are commonly encountered. These thermo-acoustic instabilities can cause undesirable noise, vibrations, local thermal and mechanical stresses in the combustor and are prominent in lean combustion. LÄS MER
Sammanfattning : In the present thesis, computational methods for theanalysis and design of photonic bandgap structure areconsidered. Many numerical methods have been used to study suchstructures. Among them, the plane wave expansion method is veryoften used. LÄS MER
Sammanfattning : Photonic crystals are materials with periodically varying refractive indices. In conventional photonic crystal design it is hard to achieve tunable structures in the visible range. That is, structures with changeable optical properties. LÄS MER
4. Acoustic, Thermal and Non-thermal Dynamics in Condensed Matter Studied by Time-Resolved X-ray Diffraction
Sammanfattning : The method of using short laser and X-ray pulses to investigate dynamics in materials (pump-probe) has been used for several decades. This thesis presents work that was carried out using these sources of light to reveal acoustic, thermal and non-thermal dynamics. LÄS MER
5. Wave Modelling Techniques for Medium and High Frequency Vibroacoustic Analysis Including Porous Materials
Sammanfattning : Numerical methods based on wave modelling are explored for the vibroacoustic analysis of wave propagation, sound transmission and interior noise in vehicles and buildings at medium and high frequencies. The presence of sound absorbing porous materials in practical engineering structures is also considered. LÄS MER