Sökning: "mechanical impedance"

Visar resultat 11 - 15 av 97 avhandlingar innehållade orden mechanical impedance.

1. 11. Studies of sound generation and propagation in flow ducts

   Författare :Fabrice Ducret; Mats Åbom; Andy Moorhouse; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; two-port; plane wave; HVAC system; tailpipe; exhaust system; flexible duct; pipe; reflection coefficient; impedance; flow noise; vorticity; damping; scaling laws; impedance; transmission loss; perforated plate; slit; non linearity; Acoustics; Akustik;

   Sammanfattning : This thesis contains three papers investigating problems of interest for noise control in ducts. The first part of this thesis treats the sound propagation in rectangular ducts with flexible walls. Various experimental techniques are performed to measure the internal sound propagation and radiation to the surrounding. LÄS MER

3. 12. Mechanical impedance gauge based on measurement of strains on a vibrated or impacted rod

   Författare :Lars Lagerkvist; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

   Sammanfattning : A mechanical impedance gauge based on measurement of strains at two cross-sections of a slender rod is studied. The gauge rod is in contact with the object at one end while the other end is excited harmonically with a vibrator or transiently through the impact of a hammer. LÄS MER

4. 13. Microstructure in SOFC: electrochemical simulations and experiments

   Författare :Xiaoqiang Zhang; Värmeöverföring; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Solid oxide fuel cell; Electrochemical impedance spectroscopy; 3D reconstruction; Tortuosity; Electrochemical kinetics; Multiphysics; Thermal stress;

   Sammanfattning : Solid oxide fuel cells (SOFCs) are highly efficient and environmentally friendly power sources that convert chemical energy directly into electricity and heat, without the need for combustion. Despite their many benefits, the performance and durability of SOFCs heavily depend on the quality of their porous anode and cathode components. LÄS MER

5. 14. Electrical Characterisations of Bearings

   Författare :Abhishek Joshi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ball bearing; Equivalent circuit model; Lubricants; Bearing Capacitance; Spherical bearing; Mechanical bearing; Bearing currents; Electrical conduction; Electrical characterisation;

   Sammanfattning : Mechanical bearings are an integral part of industry, and are used in various places in order to reduce friction between two interacting surfaces and are used to transmit power and loads. Mechanical bearings are one of the most extensively used components within the wind industry, but on the other hand they are also one of the most dominantly failing failed components. LÄS MER

7. 15. Experimental Characterization of Electrodes and Multi-Scale Modeling of Swelling Induced Stresses in Lithium-ion Batteries

   Författare :Priyank Gupta; Peter Gudmundson; Göran Lindbergh; Erik Olsson; Elham Sahraei; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; lithium-ion batteries; mechanical characterization; multiscale modeling; homogenization; Solid Mechanics; Hållfasthetslära;

   Sammanfattning : Over the last few decades, rechargeable lithium-ion batteries have been extensively used in portable instruments due to their high energy density and low self-discharge rate. Recently, lithium-ion batteries have emerged as the most promising candidate for electric vehicles and stationary energy storage. LÄS MER