technology small production can not open the ball children's science experiment kindergarten elementary school educational toys handmade diy

                                             course courseware

   vortex is a kind of airflow vortex with alternating rotation direction. this airflow vortex has a certain correlation with the vortex structure formed inside the superfluid. the former only requires ordinary temperature environment, while the latter requires extremely low temperature. the laboratory uses liquid mercury to create extremely low temperatures and form superconducting states. in this extreme case, the flow of electrons suddenly becomes unimpeded, which is called superfluid. carmen vortex isfluid mechanicsimportant phenomena can often be encountered in nature. when constant flow bypasses some objects under certain conditions, both sides of the objects will periodically fall off and rotate in opposite directions, the regular double-column linear vortex forms carmen vortex after nonlinear action. such as water flowing through the pier, wind blowing through the tower,chimney, wires, etc. will form carmen vortex street. carmen vortex street has some important applications, so it is necessary to understand its research history and related application.

vortex destruction: if the alternating shedding frequency of vortex street coincides with the acoustic standing wave frequency of the object, resonance will also occur. industrial forewarmer,boileretc. are mostly composed of circular tubes. when the fluid flows around the circular tube, the alternating shedding of karman vortex street will cause forewarmer vibration in the box gas column. if the alternating shedding frequency of vortex street coincides with the acoustic standing wave frequency of the object, acoustic resonance will be triggered, causing intense vibration of the tube box. in severe cases, the vibration drum of the forewarmer tube box will be staggered or even broken. if the natural frequency of tube box and gas is changed to be staggered with the shedding frequency of karman vortex street to avoid resonance, the damage of equipment can be prevented.