Sökning: "chevrons"

Hittade 3 avhandlingar innehållade ordet chevrons.

  1. 1. Large Eddy Simulation for the Analysis of Supersonic Jet Noise Suppression Devices

    Författare :Markus Olander Burak; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluidic injection; mixer-ejector; jet noise; Kirchhoff; forward flight effects; LES; acoustic liner; supersonic turbulent jets; broadband time-domain impedance boundary condition; chevrons; shock-associated noise; CAA; aeroacoustics;

    Sammanfattning : Stricter noise regulations for commercial and military aircraft have increased interest in noise reduction techniques within the aerospace industry. To meet the requirements, new noise suppression technologies have to be developed and numerical methods need to be validated and possibly improved for the correct assessment of these technologies. LÄS MER

  3. 2. Friction drag studies on microfabricated surface structures : a new equipment, sample manufacturing and the first results

    Författare :Håkan Rapp; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; riblets; microfabrication; plane channel; Friction drag; chevrons; shark skin; biomimetric; sand grain roughness;

    Sammanfattning : .... LÄS MER

  4. 3. Numerical methods for load and response prediction for use in acoustic fatigue

    Författare :Johan Nilsson; Byggnadsmekanik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustic fatigue; Sonic fatigue; Computational Fluid Dynamics; Large Eddy Simulation; Finite Element Method; Random response analysis; Separated flow; High Re; Backward-facing step; Fence flow; Aircraft; Proper Orthogonal Decomposition; Acoustic fatigue; Sonic fatigue; Computational Fluid Dynamics; Large Eddy Simulation; Finite Element Method; Random response analysis; Separated flow; High Re; Backward-facing step; Fence flow; Aircraft; Proper Orthogonal Decomposition;

    Sammanfattning : Acoustic fatigue can occur in structural elements of an aircraft exposed to very high sound pressures. To deal with acoustic fatigue, mainly empirical methods have been applied and often late in the design phase. Current design guidelines have three main limitations. First, they do not say anything about the load intensities. LÄS MER