Sökning: "elastic medium"

Visar resultat 6 - 10 av 38 avhandlingar innehållade orden elastic medium.

1. 6. Elastic and acoustic characterisation of anisotropic porous materials

   Författare :Rémi Guastavino; Peter Göransson; Viggo Tarnow; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustics; Akustik;

   Sammanfattning : For an accurate prediction of the low and medium frequency surface vibration and sound radiation behaviour of porous materials, there is a need to improve the means of estimating their elastic and acoustic properties. The underlying reasons for this are many and of varying origin, one prominent being a poor knowledge of the geometric anisotropy of the cell microstructure in the manufactured porous materials. LÄS MER

3. 7. Scattering of elastic waves by an anisotropic sphere

   Författare :Ata Jafarzadeh; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Sphere; T matrix; Effective wave number; Distribution of inclusions; Phase velocity.; Anisotropy; Attenuation; Scattering;

   Sammanfattning : Scattering of a plane wave by a single spherical obstacle is the archetype of many scattering problems in physics and geophysics. Spherical objects can provide a good approximation for many real objects, and the analytic formulation for a single sphere can be used to investigate wave propagation in more complicated structures like particle composites or grainy materials, which may have application in non-destructive testing, material characterization, medical ultrasound, etc. LÄS MER

4. 8. Models of porous, elastic and rigid materials in moving fluids

   Författare :Ugis Lacis; Shervin Bagheri; Fredrik Lundell; Lakshminarayanan Mahadevan; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluid-structure-interaction; flow control; passive appendages; homogenization; poroelastic coatings; separated flows; surface-fluid interface; fluid-struktur-interaktion; flödeskontroll; passiva utväxter; homogenisering; ytbeläggning; separerade strömning; ytbeläggning-strömning gränssnitt; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : Tails, fins, scales, and surface coatings are used by organisms for various tasks, including locomotion. Since millions of years of evolution have passed, we expect that the design of surface structures is optimal for the tasks of the organism. These structures serve as an inspiration in this thesis to identify new mechanisms for flow control. LÄS MER

5. 9. Scattering of elastic waves by an anisotropic sphere with application to polycrystalline materials

   Författare :Ata Jafarzadeh; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Spherical obstacle; Anisotropy; Attenuation; Polycrystalline materials; Effective wave number; T matrix; Phase velocity; Scattering;

   Sammanfattning : Scattering of a plane wave by a single spherical obstacle is the archetype of many scattering problems in various branches of physics. Spherical objects can provide a good approximation for many real objects, and the analytic formulation for a single sphere can be used to investigate wave propagation in more complex structures like particulate composites or grainy materials, which may have applications in non-destructive testing, material characterization, medical ultrasound, etc. LÄS MER

7. 10. Laser Diagnostics and Chemical Modeling of Combustion and Catalytic Processes

   Författare :Michael Försth; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; catalysis; platinum; OH; elastic light scattering; planar LIF; fuel spray; surface reactions; imaging; Chemkin; hydroxyl; stagnation flow; gas-phase chemistry;

   Sammanfattning : The H2+1/2O2 H2O reaction on hot platinum surfaces has been studied. A stagnation flow geometry was used with a gas mixture of H2 and O2 at subatmospheric pressures. LÄS MER