Sökning: "Modal Flow Decomposition"

Visar resultat 1 - 5 av 22 avhandlingar innehållade orden Modal Flow Decomposition.

  1. 1. Modal Decomposition of Separated Nozzle Flow

    Författare :Ragnar Larusson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Arnoldi; axisymmetric convergent-divergent nozzle; Mode Decomposision; Flow Separation; Resonance.; Dynamic Mode Decomposision; Computational Fluid Dynamics;

    Sammanfattning : The applicability of two different eigenvalue algorithms coupled with an axisymmetric RANS solver to predict the eigenmodes of separated supersonic flow inside an axisymmetric convergent-divergent nozzle was investigated. These are the Arnoldi and the Dynamic Mode Decomposition (DMD) algorithms, respectively. LÄS MER

  3. 2. Modal Analysis of Supersonic Flow Separation in Nozzles

    Författare :Ragnar Larusson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Separated Nozzle Flow; Dynamic Mode Decomposition; Hybrid RANSLES; CFD; Modal Analysis; Arnoldi;

    Sammanfattning : Operating a convergent-divergent nozzle under overexpanded conditions can lead to supersonic flow separation in the divergent section of the nozzle. In this case, an attached oblique shock wave forms at the separation base. LÄS MER

  4. 3. Centrifugal compressor flow instabilities at low mass flow rate

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

    Sammanfattning : 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. LÄS MER

  5. 4. Large Eddy Simulation of Turbulent Compressible Jets

    Författare :Bernhard Semlitsch; Mihai Mihaescu; Laszlo Fuchs; Paul G. Tucker; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Compressible Flow; Large Eddy Simulation; Acoustic Noise Generation; Near-field Acoustics; Flow Control; Optimization; Modal Flow Decomposition; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning : Acoustic noise pollution is an environmental aggressor in everyday life. Aero- dynamically generated noise annoys and was linked with health issues. It may be caused by high-speed turbulent free flows (e.g. LÄS MER

  7. 5. Drag Reduction by means of Active Flow Control Applied on a Generic Truck A-pillar: a Numerical and Experimental Study

    Författare :Guglielmo Minelli; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; PANS; Large Eddy Simulation; Wind Tunnel.; Bluff Body Flow; Modal Decomposition; Experiments; Vehicle Aerodynamic; POD; Active Flow Control; LES; Partially Averaged Navier Stokes; AFC;

    Sammanfattning : The overall goal of this thesis is to isolate and control the flow mechanism characterizing the flow separation occurring at the A-pillar of a truck. The study aims to gain knowledge of the flow physics of the separation mechanism, and to eventually suppress the afore mentioned separation by means of an Active Flow Control. LÄS MER