Numerical investigation of flow structure and pressure pulsation in the Francis-99 turbine during startup

Francis-99 Workshop 2: transient operation of Francis turbines

Minakov, A.^1,2 ; Sentyabov, A.^1,2 ; Platonov, D.^1,2

Siberian Federal University, Svobodniy 79, Krasnoyarsk

660079, Russia^1

Institute of Thermophysics SB RAS, Lavrentyeva 1, Novosibirsk

630090, Russia^2

关键词: Francis hydro-turbine;    Linear approximations;    Low-frequency pressure pulsations;    Nonstationary process;    Numerical investigations;    Pressure pulsation;    Shear-stress transport;    Vortex rope;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/782/1/012004/pdf
DOI  :  10.1088/1742-6596/782/1/012004

来源: IOP

【 摘 要 】

We performed numerical simulation of flow in a laboratory model of a Francis hydroturbine at startup regimes. Numerical technique for calculating of low frequency pressure pulsations in a water turbine is based on the use of DES (k-ω Shear Stress Transport) turbulence model and the approach of "frozen rotor". The structure of the flow behind the runner of turbine was analysed. Shows the effect of flow structure on the frequency and intensity of non-stationary processes in the flow path. Two version of the inlet boundary conditions were considered. The first one corresponded measured time dependence of the discharge. Comparison of the calculation results with the experimental data shows the considerable delay of the discharge in this calculation. Second version corresponded linear approximation of time dependence of the discharge. This calculation shows good agreement with experimental results.