Search for dissertations about: "vibration reduction"

Showing result 36 - 40 of 80 swedish dissertations containing the words vibration reduction.

  2. 36. Estimation and Control of Resonant Systems with Stochastic Disturbances

    Author : Peter Nauclér; Torsten Söderström; Anders Robertsson; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vibration control; stochastic control; stochastic systems; feedforward control; Wiener filtering; Kalman filtering; wave separation; unbalance estimation; nonlinear regression; Automatic control; Reglerteknik;

    Abstract : The presence of vibration is an important problem in many engineering applications. Various passive techniques have traditionally been used in order to reduce waves and vibrations, and their harmful effects. Passive techniques are, however, difficult to apply in the low frequency region. READ MORE

  4. 37. Foam, Fire and Free Volume - Chemical and Physical Aspects of Porous Polymers

    Author : Anna Andersson; Centrum för analys och syntes; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Poisson ratio; vibration damping; acoustic impedance; cell morphology; hyperbranched polymer; Polymer foams; free volume; positron annihilation; supercritical fluid.;

    Abstract : Automotive seating has been under continous development since it was described for the first time in 1885. At that time one could read about a “padded leather bench seat sitting on springs mounted directly to the frame of a horse-less carriage”. READ MORE

  5. 38. Procedure for the reduction of the effect of transient whole body vibrations

    Author : Peter Jönsson; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Teknisk akustik; Engineering Acoustics;

    Abstract : There is a growing interest in the topic areas of increased vibration comfort and reduced vibration levels in work vehicles. Legislation, health costs and demands for increased competitiveness are all important motivating factors in this growing interest. READ MORE

  6. 39. Reduction of Audible Noise of a Traction Motor at PWM Operation

    Author : Hanna Amlinger; Ines Lopez Arteaga; Siv Leth; Wolfgang Kropp; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electromagnetic noise; pulse width modulation PWM ; switching frequency; traction motor; Vehicle and Maritime Engineering; Farkostteknik;

    Abstract : A dominating source for the radiated acoustic noise from a train at low speeds is the traction motor. This noise originates from electromagnetic forces acting on the structure resulting in vibrations on the surface and thus radiated noise. It is often perceived as annoying due to its tonal nature. READ MORE

  7. 40. Numerical Investigation of the Aerodynamic Vibration Excitation of High-Pressure Turbine Rotors

    Author : Markus Jöcker; KTH; []
    Keywords : Aeroelasticity; Aerodynamics; Stator-Rotor Interaction; Excitation Mechanism; Unsteady Flow Computation; Forced Response; High Cycle Fatigue; Turbomachinery; Gas-Turbine; High-Pressure Turbine; Turbopump; CFD; Design;

    Abstract : The design parameters axial gap and stator count of highpressure turbine stages are evaluated numerically towards theirinfluence on the unsteady aerodynamic excitation of rotorblades. Of particular interest is if and how unsteadyaerodynamic considerations in the design could reduce the riskofhigh cycle fatigue (HCF) failures of the turbine rotor. READ MORE