Sökning: "Cylindrical holes"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden Cylindrical holes.

1. 1. On Film Cooling of Turbine Guide Vanes : From Experiments and CFD-Simulations to Correlation Development

   Författare :Hossein Nadali Najafabadi; Matts Karlsson; Esa Utriainen; Mats Kinell; Valery Chernoray; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Film Cooling; Gas Turbine; Correlation; CFD; Cylindrical holes; Fan-shaped Holes;

   Sammanfattning : To achieve high thermal efficiency in modern gas turbines, the turbine-inlet temperature has to be increased. In response to such requisites and to prevent thermal failure of the components exposed to hot gas streams, the use of different cooling techniques, including film cooling, is essential. LÄS MER

3. 2. Optical properties of nanometer disks, holes and rings prepared by colloidal lithography

   Författare :Per Hanarp; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; colloidal lithography; nanoparticles; nanorings; localized surface plasmon resonance; electrostatic self-assembly; nanofabrication; sub-wavelength holes;

   Sammanfattning : The optical properties of nanostructures prepared by colloidal lithography are studied. Colloidal lithography is a fabrication approach based on a self-assembling pattern definition. An electrostatically self-assembled array of nanoparticles is used as a mask and combined with etching or deposition processes. LÄS MER

4. 3. Computational analysis and design optimization for acoustic devices

   Författare :Abbas Mousavi; Eddie Wadbro; Martin Berggren; Niels Aage; Umeå universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Design optimization; computational analysis; viscothermal acoustics; material distribution topology optimization; acoustic black holes; finite element method;

   Sammanfattning : This thesis focuses on material distribution topology optimization for acoustic waveguides. The limitations of the material distribution approach are discussed in the context of acoustic waveguides with extensive viscous and thermal boundary losses. LÄS MER

5. 4. Manipulation of Light with Transformation Optics

   Författare :Wei Yan; Min Qiu; Niels Asger Mortensen; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; transformation optics; Maxwell’s equations; invisibility cloaks; compensated bilayer; perfect imaging; optical illusion; nihility media; α media; Optics; Optik;

   Sammanfattning : Transformation optics, a recently booming area, provides people a new approach to design optical devices for manipulating light. With transformation optics, a lot of novel optical devices are proposed, such as invisibility cloaks, optical wormholes, optical black holes, illusion devices. LÄS MER

7. 5. Periodic Structures with Higher Symmetries: Analysis and Applications

   Författare :Fatemeh Ghasemifard; Martin Norgren; Oscar Quevedo-Teruel; Guido Valerio; Stefano Maci; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; periodic structures; higher symmetries; dispersion analysis; mode matching; generalized Floquet theorem; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : In this thesis, periodic structures with higher symmetries are studied. Their wave propagation characteristics are investigated and their potential applications are discussed. Higher-symmetric periodic structures are described with an additional geometrical operation beyond a translation operator. LÄS MER