Abstract: Hydraulic vibration source influences the normal operation of hydropower unit, and induces the vibration of powerhouse. As the most important source among the three vibration sources, hydraulic source distributes widely and affects large areas. Current research on the characteristics of hydraulic source mainly depends on model test which has scale error and is in lack of monitoring points. Also the stability calculation for hydropower unit and power house is excessively simplified. In view of this, a new approach of researching hydraulic source is put forward according to CFD (computational fluid dynamics) numerical simulation. The hydraulic source is converted into incitation on rotational wheel, spiral case and tail water tube to research the stability of unit and power house.

Key words: hydraulic pulse, CFD numerical simulation, unit, hydropower house, vibration