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Vortex Evolution and Energy Production in the Blade Channel of a Francis Turbine Operating at Deep Part Load Conditions
Author(s): An YU, Yongshuai Wang, Daqing Zhou
Keywords: Francis turbine; Vortex evolution; Energy Production; Vorticity transport equation; Entropy production theory
The blade vortex evaluation in Francis Turbine under deep part load conditions generate severe pressure fluctuations in the runner. The complex flow in a model turbine is numerically investigated based on a modified Partially Averaged Navier-Stokes method. Main emphasis is focus on revealing the correlation mechanism of blade vortex evolution and energy production. The results indicate that The MPANS method shows significant advantages in hydro turbine’s simulation than traditional RANS method. At deep part load condition, the vorticity formed at the leading edge of the suction surface and the trailing edge of the pressure surface in the blade channels. The stretching term provides the most vorticity increments while the dilation term inhibiting part which only provide decrement of the vorticity evolution. Based on the entropy production theory, the total entropy production distribution is consisting with the distribution of vorticity. At deep part load condition, direct dissipation and turbulent dissipation provides the most entropy, while at part load condition the proportion of these two-part decreased.

Journal of Applied Fluid Mechanics

The Journal of Applied Fluid Mechanics (JAFM) is an international, peer-reviewed journal which covers a wide range of theoretical, numerical and experimental aspects in fluid mechanics. The emphasis is on the applications in different engineering fields rather than on pure mathematical or physical aspects in fluid mechanics. Although many high quality journals pertaining to different aspects of fluid mechanics presently exist, research in the field is rapidly escalating.