In order to study effect of different entrance sections on pressure pulsation within hydraulic turbine

a single stage hydraulic turbine was selected

and the internal flow field of hydraulic turbine was calculated and analyzed by software CFX; by setting the monitoring points in each flow components

the pressure pulsation at each monitoring points under different entrance sections was calculated; finally

the calculation results of pressure pulsation were switched by means of fast Fourier transformation(FFT) algorithm

and the distribution of time domain and frequency domain at each monitoring point was analyzed. Result show that with the increase of entrance diameter of volute

the pressure gradually increased at each monitoring point under the larger entrance of volute in the volute

but the pressure gradually decreased at each monitoring point under the smaller entrance of volute. The pressure pulsation was less under the larger entrance of volute when the monitoring points and the shrinkage tube were a greater distance apart

but the pressure pulsation was less under the smaller entrance of volute when the monitoring points and the shrinkage tube were a smaller distance apart. The difference of pressure pulsation of different entrance sections gradually decreased from entrance to outlet at the same time in the impeller. The pressure pulsation of draft tube entrance was maximum under the smaller entrance of volute in the draft tube.