Search for dissertations about: "Acoustic horn"

Showing result 1 - 5 of 7 swedish dissertations containing the words Acoustic horn.

  2. 1. Numerical Techniques for Acoustic Modelling and Design of Brass Wind Instruments

    Author : Daniel Noreland; Bertil Gustafsson; Leif Abrahamsson; Björn Sjögreen; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Acoustic horn; brass wind instrument; loudspeaker; optimization; hybrid method; Numerical Analysis; Numerisk analys;

    Abstract : Acoustic horns are used in musical instruments and loudspeakers in order to provide an impedance match between an acoustic source and the surrounding air. The aim of this study is to develop numerical tools for the analysis and optimisation of such horns, with respect to their input impedance spectra. READ MORE

  4. 2. Shape Optimization for Acoustic Wave Propagation Problems

    Author : Rajitha Udawalpola; Martin Berggren; Pekka Neittaanmäki; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; shape optimization; design optimization; acoustic wave propagation; Helmholtz equation; Boundary Element Method; Finite Element Method; inverse problems; adjoint method; gradient-based optimization; Scientific Computing; Beräkningsvetenskap;

    Abstract : Boundary shape optimization is a technique to search for an optimal shape by modifying the boundary of a device with a pre-specified topology. We consider boundary shape optimization of acoustic horns in loudspeakers and brass wind instruments. READ MORE

  5. 3. Topology optimization for acoustic wave propagation problems

    Author : Eddie Wadbro; Martin Berggren; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Scientific Computing; Beräkningsvetenskap;

    Abstract : The aim of this study is to develop numerical techniques for the analysis and optimization of acoustic horns for time harmonic wave propagation. An acoustic horn may be viewed as an impedance transformer, designed to give an impedance matching between the feeding waveguide and the surrounding air. READ MORE

  6. 4. Analysis, Control, and Design Optimization of Engineering Mechanics Systems

    Author : Esubalewe Lakie Yedeg; Martin Berggren; Eddie Wadbro; Anton Evgrafov; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Topology optimization; Helmholtz equation; acoustic impedance; anisotropic filter; thin structures; finite element method; Nitsche-type method; interface problem; Optimal control; adjoint method; business data processing; administrativ databehandling;

    Abstract : This thesis considers applications of gradient-based optimization algorithms to the design and control of some mechanics systems. The material distribution approach to topology optimization is applied to design two different acoustic devices, a reactive muffler and an acoustic horn, and optimization is used to control a ball pitching robot. READ MORE

  7. 5. Application of the Boundary Element Method to combustion noise and half-space problems

    Author : Haike Brick; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; impedance plane; Green s function; horn effect; Kirchhoff s surface; Hybrid approach; tyre-road interface;

    Abstract : The Boundary-Element-Method (BEM) is a powerful and established tool in computational acoustics. This thesis aims at an enhancement of the method towards combustion noise and half-space problems.First, it is directly coupled to an incompressible Large Eddy Simulation (LES) to calculate the sound radiation of open flames. READ MORE