Search for dissertations about: "tonal noise."

Showing result 1 - 5 of 23 swedish dissertations containing the words tonal noise..

2. 1. Numerical investigation of tonal noise sources from centrifugal fan

   Author : Martin Ottersten; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Computational Aeroacoustics; Tonal Noise; Centrifugal Fan; Blade Passing Frequency;

   Abstract : Heating, ventilating, and air conditioning systems (HVAC) are today an important part of many people's life. They provide a sufficient amount of airflow with the correct temperature, quality, and humidity. The negative side is the noise it produces. Many improvements have been made in building development to reduce noise from the environment. READ MORE

4. 2. Investigation of Tonal Noise Sources from Centrifugal Fan using Detached Eddy Simulation

   Author : Martin Ottersten; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Computational aeroacoustics; Blade passing frequency; Centrifugal fan; Low-frequency rotation; Tonal noise.;

   Abstract : Since we spend the majority of our time indoors, heating, ventilation, and air conditioning (HVAC) systems have become a more and more important part of many people´s life. They provide a sufficient amount of airflow with the correct temperature, quality, and humidity. READ MORE

5. 3. A few aspects of aircraft noise

   Author : Crispin Dickson; Shafiquzzaman Khan; Mendel Kleiner; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; paired comparison; sorting based paired comparison; sorting algorithms; mergesort; quicksort; aircraft sound synthesis; aircraft noise; sound quality; tonal effects; angle positions; flight conditions; methods of equalization; cognition; Acoustics; Akustik;

   Abstract : A few aspects of aircraft noise were evaluated. These were (i) methods of subjective evaluations, (ii) effects of equalization and (iii) the effects of cognitive aspects.In the first paper, sorting algorithms were used instead of conventional paired comparison method in order to reduce the number of pairs in the evaluation of subjective judgments. READ MORE

6. 4. Numerical Methods for Aeroacoustic Analysis of Turbomachinery

   Author : Daniel Lindblad; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Convective Ffowcs Williams - Hawkings Equation; Computational Aeroacoustics; Acoustic Analogy; Von Neumann Stability Analysis; Tonal Noise; CAA; Harmonic Balance Method; Counter Rotating Open Rotor;

   Abstract : Air transportation is today an integral part of many peoples life and it continuously grow to serve more of us in new and ingenious ways. There are however negative sides to this growth as well, such as increased noise around airports and more CO2 emissions, which must be addressed if aviation is to be part of a sustainable future. READ MORE

7. 5. Numerical Methods for Aeroacoustic Analysis of Turbomachines

   Author : Daniel Lindblad; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Stability Analysis; Acoustic Analogy; Tonal Noise; Nonreflecting Boundary Conditions; Duct Modes; Turbomachinery; Harmonic Balance; Ffowcs Williams - Hawkings; Time Sampling; Aliasing;

   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