Velocity and pressure distributions in discharge tunnel of rotary-obstruction composite inner energy dissipation

On the basis of model test and theoretical analysis of velocity and pressure distributions, an hypothesis is presented that the distribution of tangential velocity in radial direction seems to be a combinational distribution of a quasi-free vortex and a quasiforced vortex for the discharge tunnel of rotary-obstruction composite inner energy dissipation. The variations of corresponding parameters about the hypothesis are obtained under test conditions in this paper. The formula of pressure distribution in radial direction is deduced theoretically, and the theoretical values of pressure distribution computed by the formula are well consistent with the measured ones, showing that the formula is correct and can be applied to the computation and analysis of pressure distribution of this discharge tunnel.