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Force calculations in permanent magnetic bearing
Bachorec, T. ; Šafr, M. ; Kozánek, Jan
Calculation of forces in permanent magnetic radial bearing by means of finite element method is presented and its results are compared with analytical estimates. From these results, the (slightly non-linear) relationship force versus radial displaceme is derived and the working position of rotor in the stator and predicted bearing stiffness are determined.
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Measurement of acoustic pressure in supraglottal spaces
Vokřál, J. ; Vohradník, M. ; Horáček, Jaromír
The aim is the measurement of acoustic pressure in supraglottal acoustic spaces by miniature microphones. The microphone was placed at the end of laryngeal wire applicator and its position was changed continually from the mouth to the vocal folds. This sources of acoustic signal were used: the own voice - vowels ´A´ and ´E´, and the electronic laryns. Natural frequencies nad acoustic mode shapes of the air vibration were investigated.
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Vibration cylindrical shells containing flowing fluid
Zolotarev, Igor
The natural frequencies of free vibration of a circular cylindrical shell containing flowing inviscid fluid are studied. The numerical results obtained by use simple 1-D shell theory are compared with results obtained by use 3-D shell theory and by us NSYS numerical package. Critical flow velocity is analyzed for several shape mode of studied cylindrical shell.
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