Search for dissertations about: "Duct Modes"
Showing result 1 - 5 of 11 swedish dissertations containing the words Duct Modes.
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1. Integrated Duct Aerodynamics
Abstract : Air traffic is rapidly increasing, with no sign of slowing down, resulting in increased green-house gases emission. With emission criteria becoming stricter every year, the aircraft design is subjected to continuous improvements. The development of more efficient aircraft engines plays a central role in the strive towards lower emission levels. READ MORE
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2. Numerical Methods for Aeroacoustic Analysis of Turbomachines
Abstract : Numerical simulations are important tools for developing new aircraft that can meet future needs. When numerical simulations are used to compute aircraft noise, a two-step procedure is often employed. In the first step, the noise sources are determined using, e.g. READ MORE
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3. Experimental and Numerical Multi-port Eduction for Duct Acoustics
Abstract : Sound generation and propagation in circular ducts for frequencies beyond the cut-on frequencies of several higher order acoustic modes is investigated. To achieve this, experimental and numerical set-ups are designed and used to research aeroacoustic interactions between in-duct components and to conceive noise mitigation strategies. READ MORE
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4. Spectral-element simulations of turbulent wall-bounded flows including transition and separation
Abstract : The spectral-element method (SEM) is used to study wall-bounded turbulent flowsin moderately complex geometries. The first part of the thesis is devoted to simulations of canonical flow cases, such as temporal K-type transitionand turbulent channel flow, to investigate general resolution requirements and computational efficiency of the numerical code nek5000. READ MORE
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5. Acoustic scattering in ducts and influence of flow coupling
Abstract : The subject of this thesis is the acoustic properties offlow duct area expansions and the influence of flow-acousticcoupling at sharp edges. For low Mach number flow, significantinteraction between the sound field and the flow field canoccur at such points of flow separation. READ MORE