Search for dissertations about: "Fourier decomposition"

Showing result 21 - 25 of 29 swedish dissertations containing the words Fourier decomposition.

  2. 21. Flow instabilities in centrifugal compressors at low mass flow rate

    Author : Elias Sundström; Mihai Mihaescu; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Centrifugal compressor; flow instabilities; rotational flows; rotating stall; surge; compressible Large Eddy Simulation; Engineering Mechanics; Teknisk mekanik;

    Abstract : A centrifugal compressor is a mechanical machine with purpose to convert kineticenergy from a rotating impeller wheel into the fluid medium by compressingit. One application involves supplying boost air pressure to downsized internalcombustion engines (ICE). READ MORE

  4. 22. Nonlinear rheological characterization of cellulose nanocrystals based systems

    Author : Sylwia Wojno; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; cellulose; rheo-PLI; CNC; FT-rheology; rheology;

    Abstract : In this thesis, cellulose nanocrystals based systems were investigated using advanced rheological characterization techniques, with a particular focus on nonlinear material response functions and Rheo-PLI (Polarized Light Imaging). Cellulose nanocrystals (CNCs) show enormous potential for many applications, either as material on its own or as renewable reinforcement in polymers. READ MORE

  5. 23. Li2O2 quantification in non-aqueous Li-O2 batteries with binder-free cathodes

    Author : Chenjuan Liu; Torbjörn Gustafsson; Martin Sahlberg; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : The non-aqueous Li-air (Li-O2) battery has been emerging as one of the most promising high-energy storage systems to meet the requirements for electric vehicle applications due to its high theoretical energy density. In order to uncover the underlying electrochemistry and enable an informed battery design, it is crucial to gain a detailed understanding of the cell´s chemical components as well as its behavior during cycling. READ MORE

  6. 24. The Axisymmetric Turbulent Jet

    Author : Stephan Gamard; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : This thesis aims at understanding the downstream evolution of the most energetic features of a turbulent axisymmetric jet. The study was conducted from 2 to 69 diameters downstream, using 3 different jet exit diameters with air flowing at a wide range of velocities to ensure a reasonable span of Reynolds numbers, while still keeping it in a high range, from 40,000 to 156,700. READ MORE

  7. 25. Filtering extracting features from infrasound data

    Author : José Chilo; Thomas Lindblad; Christian Bohm; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; infrasound; seismic signals; feature extraction; wavelets; fingerprints; mining; magnetometer; Physics; Fysik; Electronics;

    Abstract : The goal of the research presented in this thesis is to extract features, to filter and get fingerprints from signals detected by infrasound, seismic and magnetic sensors. If this can be achieved in a real time system, then signals from various events can be detected and identified in an otherwise torrent data. READ MORE