Experimental study of pressure fluctuation in stilling basins

Stilling basins dissipate energy to form hydraulic jumps and rotational flows. hydraulic jump and rotational current phenomenon produce pressure fluctuation at the bottom of stilling basins. in the present study,pressure fluctuations and their locations have been studied in a physical model of namrod dam. results showed that fluctuations in presence of jump in the basin are high and,therefore,the fluctuation factors are,respectively,high. in positive pressure coefficient (c+ p),it is evident that when a jump is present,the turbulence and disturbance factors increase and,therefore,the pressure fluctuations go up,respectively. in negative pressure coefficients (c− p),as is expected from positive pressure coefficients,the maximum pressure fluctuations occurred at q/qmax = 0.47 with regard to forming a complete hydraulic jump at this discharge. regarding available empirical equations,the thickness of slab for different hydraulic conditions was calculated and compared in one-dimensional (1d) and two-dimensional (2d) conditions. by analyzing collected data,it was observed that,results of 1d were underestimated in comparison to 2d calculations. concrete slab thickness could be observed that fluctuations have significant effect on thicknesses. however,such calculations can provide designers with general ideas on how to better understand the conditions. © iran university of science and technology 2016.