Sökning: "aircraft noise"

Visar resultat 1 - 5 av 51 avhandlingar innehållade orden aircraft noise.

  1. 1. Active Noise Control in Aircraft : Algorithms and Applications

    Författare :Sven Johansson; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; active noise control; feedforward control; filtere-x lms algorithm; complex lms; multichannel system; multiple reference; aircraft; headset;

    Sammanfattning : The thesis consists of five papers which are divided into three main parts. Parts A and B deal with active noise control in a propeller aircraft application, whereas Part C deals with active noise control in a helicopter application. LÄS MER

  2. 2. A few aspects of aircraft noise

    Författare :Crispin Dickson; Shafiquzzaman Khan; Mendel Kleiner; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; 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;

    Sammanfattning : 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. LÄS MER

  3. 3. Acoustical Characteristics of Aircraft Panels

    Författare :Bilong Liu; Leping Feng; Jie Pan; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustics; sound transmission loss; stiffener; stiffening; aircraft panel; cylindrical shell; turbulent boundary layer; TBL; noise; sound radiation; Acoustics; Akustik;

    Sammanfattning : A deterministic approach based on a modal expansion and modal receptance method has been developed to evaluate the airborne sound insulation of aircraft panels with stringer and ring frame attachments. Furthermore, this method was extended to predict the noise radiation of stiffening panel subjected to TBL excitation. LÄS MER

  4. 4. Individual Preferences, Choices, and Risk Perceptions - survey based evidence

    Författare :Elina Lampi; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; administrators; aircraft; airports; birth order; choice experiment; citizens; environmental policy; female infertility; free entrance; general risk; health care; information; media; museum; natural experiment; noise; only-child; optimistic bias; personal risk; positional concern; relative income; siblings; stated preferences; visitor composition.;

    Sammanfattning : Paper 1 investigates how birth order and having siblings affect positional concerns in terms of success at work and of income. We find that only-children are the most positional, but that number of siblings increases the concern for their position among those who grew up together with siblings. LÄS MER

  5. 5. Active Control of Propeller-Induced Noise in Aircraft : Algorithms & Methods

    Författare :Sven Johansson; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; active control of sound; active noise control; anc; actuator individual normalized filtered-x lms; filtered-x lms algorithm; newton algorithm; complex lms; multireference algorithm; leaky lms; control effort weighting; feedforward control; feedback contro;

    Sammanfattning : In the last decade acoustic noise has become more and more regarded as a problem. In cars, boats, trains and aircraft, low-frequency noise reduces comfort. Lightweight materials and more powerful engines are used in high-speed vehicles, resulting in a general increase in interior noise levels. LÄS MER