Page 273 - Fluid-Structure Interactions Slender Structure and Axial Flow (Volume 1)
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254               SLENDER STRUCTURES AND AXIAL FLOW



                                                           water flow
                                                                   1






                           -.
                        To reciprocating
                        mechanism




                                              Wall-mounted



                                              Hot-film anemometer
















                                                  Cantilevered  test pipe






                                                       To collecting tank  I
                                                       on weighing scale   (io (1 + pcos Or)
                    Figure 4.30  Schematic  diagram  of  the  apparatus  used  for  parametric  oscillations  of  pipes
                                         conveying fluid (Paldoussis & Issid 1976).

                    agreement between theory and experiment is particularly poor in the case of the secondary
                    resonance. This is probably due to interference by forced vibration, transmitted through
                    the apparatus, which resulted in effectively widening the region of resonance.
                      The dynamical behaviour in the  case of  cantilevered pipes  is described next. It was
                    found that unless the flow velocity was fairly close to the critical value,  U,f, at which
                    the system loses stability by  flutter in  steady flow, the system remained stable, at least
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