The numerical simulation of low frequency pressure pulsations in the high-head Francis turbine


Тип публикации: статья из журнала

Год издания: 2015

Идентификатор DOI: 10.1016/j.compfluid.2015.01.007

Ключевые слова: Francis turbine, Pressure pulsation, Precessing vortex rope, Turbulence, Mathematical model, Computational fluid dynamics, Francis turbines, Hydraulic turbines, Mathematical models, Numerical methods, Turbulence models, Vortex flow, Vorticity, Integral characteristics, Low-frequency pressure pulsations, Nonstationary process, Numerical techniques, Transient phenomenon, Unsteady turbulent flows, Vortex rope

Аннотация: Numerical technique for calculating pressure pulsations in the high-head hydro turbines is presented in the paper. The numerical technique is based on the use of DES turbulence model and the approach of "frozen rotor". This technique is applied for simulating unsteady turbulent flow in a flow path of a high head hydropower plant. TПоказать полностьюhe flow structure downstream the runner and its influence on the intensity of non-stationary processes is analyzed. It is shown that the low-frequency pressure pulsations in water turbines are mainly caused by the precessing vortex rope downstream the runner. The vortex dynamics basically determines the pulsational characteristics of turbine operation. It is found that the averaged velocity components of flow downstream the runner can serve as indicators, which characterize the intensity of transient phenomena in the draft tube of water turbine. The comparison of simulation results with the experimental data shows reasonable agreement in the integral characteristics (efficiency, flow rate, power) as well as pulsational characteristics (intensity and frequency) of the flow and turbine operation. (C) 2015 Elsevier Ltd. All rights reserved.

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Выпуск журнала: Vol. 111

Номера страниц: 197-205

ISSN журнала: 00457930

Место издания: OXFORD