Sökning: "acoustic source"
Visar resultat 1 - 5 av 133 avhandlingar innehållade orden acoustic source.
1. Acoustic source characterisation for non-linear in-duct sources
Sammanfattning : Different ways to model acoustic in-duct sources have beenanalysed. Measurements were conducted on two diesel truckengines. It was found that for steady state oscillations, onecould linearise in the neighbourhood of a given linearisationpoint, i.e. LÄS MER
2. Studies of flow duct acoustics with applications to turbocharged engines
Sammanfattning : A number of experimental and theoretical studies, performed in the field of technical flow duct acoustics are presented in this thesis. The acoustical methods treated are implemented on turbocharged IC-engines and engine gas exchange system components. A new method based on the well-known two-load technique has been developed. LÄS MER
3. Acoustic In-duct Characterization of Fluid Machines with Applications to Medium Speed IC-engines
Sammanfattning : The unwanted sound, noise, can lead to health problems, e.g. hearing loss and stress-related problems. A pre-knowledge of noise generation by machines is of great importance due to the ever-shorter product development cycles and stricter noise legislation. LÄS MER
4. Computational Aeroacoustics Based on Large Eddy Simulation and Acoustic Analogies
Sammanfattning : The thesis presents a numerical method developed by the author and its applications for computing the generated sound by an unsteady flow field and its propagation. The full equations of motion for compressible and unsteady flows describe both flow field and sound generation and propagation. LÄS MER
5. Acoustic Sound Source Localisation and Tracking : in Indoor Environments
Sammanfattning : With advances in micro-electronic complexity and fabrication, sophisticated algorithms for source localisation and tracking can now be deployed in cost sensitive appliances for both consumer and commercial markets. As a result, such algorithms are becoming ubiquitous elements of contemporary communication, robotics and surveillance systems. LÄS MER