Sökning: "Eigenfrequency"

Visar resultat 1 - 5 av 17 avhandlingar innehållade ordet Eigenfrequency.

1. 1. Vertical Axis Wind Turbines : Tower Dynamics and Noise

   Författare :Erik Möllerström; Jonny Hylander; Fredric Ottermo; Göran Sidén; Hans Bernhoff; Mats Åbom; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VAWT; H-rotor; eigenfrequency; semi-guy-wired tower; noise emission; sound power level;

   Sammanfattning : Vertical axis wind turbines (VAWTs) have with time been outrivaled by the today common and economically feasible horizontal axis wind turbines (HAWTs). However, VAWTs have several advantages such as the possibility to put the drive train at ground level, lower noise emissions and better scaling behavior which still make them interesting for research. LÄS MER

3. 2. Noise, eigenfrequencies and turbulence behavior of a 200 kW H-rotor vertical axis wind turbine

   Författare :Erik Möllerström; Jonny Hylander; Fredric Ottermo; Hans Bernhoff; Göran Sidén; Mats Åbom; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VAWT; H-rotor; eigenfrequency; semi-guy-wired tower; noise emission; sound power level; microphone array; turbulence intensity; power curve; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

   Sammanfattning : Vertical-axis wind turbines (VAWTs) have with time been outrivaled by the today more common and economically feasible horizontal-axis wind turbines (HAWTs). However, VAWTs have several advantages which still make them interesting, for example, the VAWTs can have the drive train at ground level and it has been argued that they have lower noise emission. LÄS MER

4. 3. Dynamic higher order equations for structural elements

   Författare :Hossein Abadikhah; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Eigenfrequency; Micropolar; Series expansion; Beam; Plate equations; Torsion;

   Sammanfattning : The subject of this thesis is to derive and evaluate governing equations and corresponding boundary conditions for solid isotropic cylinders and isotropic micropolar rectangular plates. This is achieved by a systematic power series expansion approach, by either adopting a generalized Hamilton's principle or a direct approach. LÄS MER

5. 4. Dynamic Equations foe Spherical and Cylindrical Shells Using Power Series Method

   Författare :Reza Okhovat; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; power series.; surface differential operators; shell equations; eigenfrequency; anisotropy; Spherical shell; cylindrical shell; dynamics;

   Sammanfattning : Shells are commonly used in many branches of engineeringand have therefore beeninvestigated for a number of different types of shells.A shell can be considered as a curved plate having small thickness compared to the other geometrical dimensions as well as to the wavelengths of importance. LÄS MER

7. 5. Dynamic Equations for Spherical, Orthotropic and Piezoelectric Cylindrical Shells Using the Power Series Method

   Författare :Reza Okhovat; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; shell equations; cylindrical shell; eigenfrequency.; piezoelectricity; Shells; Hamilton’s principle; surface differential operators; recursion relations; spherical shell; orthotropic; dynamics;

   Sammanfattning : Shells are commonly used in many branches of engineering, and have therefore beeninvestigated for a number of different types of shells. A shell is considered to be curved aplate with small thickness compared both to the other geometrical dimensions as well asto the wavelengths of importance. LÄS MER