Search for dissertations about: "Fourier decomposition"

Showing result 11 - 15 of 29 swedish dissertations containing the words Fourier decomposition.

  2. 11. Martingale Hardy spaces and summability of the one dimensional Vilenkin-Fourier series

    Author : George Tephnadze; Giorgi Oniani; Luleå tekniska universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

    Abstract : The classical theory of Fourier series deals with decomposition of afunction into sinusoidal waves. Unlike these continuous waves the Vilenkin(Walsh) functions are rectangular waves. READ MORE

  4. 12. Large Eddy Simulations of Complex Flows in IC-Engine's Exhaust Manifold and Turbine

    Author : Johan Fjällman; Laszlo Fuchs; Mihai Mihaescu; Ricardo Martinez-Botas; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Large Eddy Simulations; Reynolds Averaged Navier-Stokes; Turbocharger; Turbine; Curved Pipes; Pulsatile Flow; Proper Orthogonal Decomposition; Large Eddy Simulations; Reynolds Averaged Navier-Stokes; Turboladdare; Turbin; Rörkrök; Pulserande Flöde; Proper Orthogonal Decomposition; Engineering Mechanics; Teknisk mekanik;

    Abstract : The thesis deals with the flow in pipe bends and radial turbines geometries that are commonly found in an Internal Combustion Engine (ICE). The development phase of internal combustion engines relies more and more on simulations as an important complement to experiments. READ MORE

  5. 13. Fast Radon Transforms and Reconstruction Techniques in Seismology

    Author : Viktor Nikitin; Matematik LTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Fourier transform FFT ; Radon transforms; GPU;

    Abstract : The measurements conducted in tomography and seismology typically yield large multidimensional data sets. This in combination with the fact that the data may have an irregular structure makes it computationally prohibitive to use simple reconstruction methods directly. READ MORE

  6. 14. Spatial Decompositions of a Fully-developed Turbulent Round Jet Sampled with Particle Image Velocimetry

    Author : Maja Wänström; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; proper orthogonal decomposition; axisymmetric turbulent jet; PIV; spatial spectral analysis; equilibrium similarity;

    Abstract : Spatial decompositions of the turbulence in a far, axisymmetric jet at exit Reynolds number of 20, 000 have been performed. Equilibrium similaritytheory applied to the two-point Reynolds stresses has shown that the turbulence statistics in the far, fully developed region of an axisymmetric jet should be independent of origin in the streamwise direction when evaluated on the similarity coordinates system. READ MORE

  7. 15. Centrifugal compressor flow instabilities at low mass flow rate

    Author : Elias Sundström; Mihai Mihaescu; Håkan Nilsson; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Centrifugal Compressor; Large Eddy Simulation; Internal Com- bustion Engine; Aeroacoustics; Modal Flow Decomposition;

    Abstract : Turbochargers play an important role in increasing the energetic efficiency andreducing emissions of modern power-train systems based on downsized recipro-cating internal combustion engines (ICE). The centrifugal compressor in tur-bochargers is limited at off-design operating conditions by the inception of flowinstabilities causing rotating stall and surge. READ MORE