Abstract:An energy dissipation model of “X shaped flaring gate piers + bottom flow dissipation” was put forward to the problem of low energy dissipation rate for small Fr value in stilling basin. X shaped flaring gate piers were placed at the water inlet of the stilling basin to disperse water flow and increase energy dissipation rate.Through the experiment

some hydraulic parameters were observed

including the water flow patterns

the depths of the water surface line along the stilling basin

the time average pressures

the pulsant pressure characteristics and so on.Experiments showed that the water flow forms a mode of “bottom flow +stretching flow in vertical +flow of jet”

the water flow fall into the stilling basin dispersely

which took full use of the interact water flow of each other.The lengths of hydraulic jump was 6.8 to 13.3 times to the different values of the initial flow depth and conjugate flow depth;the time average pressure on crest was toally change smoothly;the root mean square of the pulsant pressure was 0.03 to 0.18 times to the inlet water.Compared with the traditional stilling basin

energy dissipation rate improved 2 to 3 times.For small Fr value in stilling basin

“X shaped flaring gate piers +bottom flow dissipation” is a worth recommending method.