Study on Dynamic Characteristics of Flap valve and Hydraulic Buffer;

The spherical floating flap valve develops from the ball-shell-type flap valve.

Combined with the flap valve model test of Fankou pumping station, the simulant method of flap valve and hydraulic hoist model is introduced and dynamic characteristics of two different schemes with variant pumping head is tested and studied.

Reduction of water column separation accompanying transient flow at two points by intercepted one-way water&board;

The experiments indicate that the waterhammer due to separated cavities collapsing at two points can be reduced by intercepting air,or installing elevated-dropped board or,adopting them simultaneously,but the range of pressure reduction and eparation length is distinct.

On the basis of experiment on control of water column separation accompanying transiet flow at two points by board, the paper studied and analysed the mechanism and effectiveness on reducing the water hammer accompanying transiet flow at two points.

The phenomenon of beats can be observed directly on the double-channel oscillograph and the frequency of alternating current can be measured by the vibration curve of the beats.

In this papaer,using double channel scope,the phenomenon of Lisaru figure and beats can be observed directly,the compose of simple harmonic motion on scope is deeply understood by the students.

Nonlinear vortex-induced force identification on beat state of 1-D bluff body vertical vortex-induced vibration

The relation between the symmetry of the beat figures and the frequency ratio n 1/n 2,the initial phases Ψ 1?Ψ 2 of the component of vibrations is analyzed.