Abstract: Pumped storage power station is an important regulating facility of the clean energy system; the hydraulic characteristics of its inlet and outlet directly affect its operation, maintenance and benefits. For the vertical inlet and outlet, most of its previous models used the grid-based Euler method, but their modelling accuracy of the flows around its orifice was low due to the bend turning. To overcome this issue, our study applies a meshless method of Lagrangian Smooth Particle Hydrodynamics (SPH) to simulate the flows in a vertical inlet and outlet connecting to a bend, by using tens of millions of particles for a real-scale simulation that is realized via GPU hardware acceleration. For the two conditions of power generation and pumping, the relative errors of the SPH method are 15.8% and 19.5% respectively in the head loss coefficient of the section from the head reservoir to the straight pipe, and 6.3% and 3.2% in the flow velocity nonuniformity coefficient of the orifice section, in comparison with the physical model measurements. The simulated flows show a good agreement of the bend section with the PIV measurements, and reveal that flow separation occurs in the diffusion section more remarkably; they reveal that no vortex is observed near the diversion cone and the orifice recirculation zone is smaller in area than that of the FLUENT case of no bend section. We find that the SPH method is more effective in simulating complex turbulent structures such as flow separation and secondary flows than the Euler method, and that our real-scale 3D SPH method is superior in producing flows around an abrupt wall shape change closer to the real cases, manifesting a great potential of further application.

Key words: hydraulics, SPH, real-scale, vertical inlet and outlet, 3D numerical simulation