Search for dissertations about: "Fluid domain"

Showing result 1 - 5 of 226 swedish dissertations containing the words Fluid domain.

2. 1. Time Domain Boundary Element Methods for Acoustic Scattering

   Author : Georgios Natsiopoulos; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; time domain; curved surface; room acoustics; boss model; boundary element method; regularization; transient; Hermite interpolation; hypersingular; acoustic scattering; vector potential;

   Abstract : In room acoustics, numerical computation of scattering phenomena is an important subject, since it is needed to accurately predict the influence of reflectors, the audience, balconies, etc, on the perceived acoustic quality of auditoria. The large physical volumes of auditoria and the wide frequency content of music and speech, together with the complicated geometries involved however, makes predictions in room acoustics a challenging task from a computational point of view. READ MORE

4. 2. Efficient time-domain modelling suitable for optimising thermoacoustic devices

   Author : Stig Kleiven; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; finite-difference; thermoacoustics; time domain; optimisation; equivalent source method; active control;

   Abstract : Thermoacoustic heat pumps use acoustic work to transfer heat from cold to hot temperatures. Such devices benefit from being environmentally friendly, robust and simple. However, in practice these devices have too low efficiency and power compared to their conventional counterparts. READ MORE

5. 3. Time-domain modelling of high-frequency wheel/rail interaction

   Author : Astrid Pieringer; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wheel rail interaction; railway noise; roughness; time domain; frictional instability; discrete irregularities; transient contact; non-Hertzian contact;

   Abstract : The interaction between wheel and rail is the predominant source of noise emission from railway operations in a wide range of conventional speeds. On the one hand, this wheel/rail noise concerns rolling noise and impact noise caused by the vertical interaction excited by roughness and discrete irregularities of the wheel/rail running surfaces, respectively. READ MORE

6. 4. Engineering model for curve squeal formulated in the time domain

   Author : Ivan Zenzerovic; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; tangential point-contact model; time domain; frictional instability; Curve squeal; rolling contact; non- Hertzian contact;

   Abstract : Curve squeal is a type of railway noise that may arise when a railway vehicle negotiates a relatively tight curve. Squeal is common in curves of a radius lower than 200 meters. A single frequency dominates the radiated sound, which makes squeal a very tonal noise. READ MORE

7. 5. Thermoacoustic refrigerators: Time-domain modelling and experimental setup

   Author : Stig Kleiven; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; finite-difference time-domain; refrigerator; thermoacoustics; equivalent source method;

   Abstract : Thermoacoustic refrigerators use acoustic waves to transfer heat. Although their benefits compared with their vapour-compression counterparts are environmental friendliness, robustness and simplicity, they are currently still less efficient than traditional vapour-compression refrigerators. READ MORE