Nestabilita vírového proudění s/bez kavitace

Instability of the swirling flows with/without cavitation

abstract

en

Swirling flows are very susceptible to instabilities. Very often they are present in draft tubes of hydraulic turbines as so called vortex ropes resulting from spiral vortex breakdown. Moreover the situation can be complicated by cavitation within the core of the vortex. Paper presents various approaches, which were applied to enhance understanding of this problem. Numerical approach to study the linear stability including influence of cavitation is proposed and extensive nonlinear CFD simulations are described.

Vírová proudění jsou velmi náchylná k nestabilitám. Nestability se v sacích troubách vodních turbín velmi často prezentují jako vírový cop. Jádro vírového copu je často vyplněno sytou párou (kavitací). Článek ukazuje různé přístupy ke studiu tohoto problému, především postupy založené na sledování stability linearizovaného systému i plně nelineární simulace založené na CFD.

Swirling flows are very susceptible to instabilities. Very often they are present in draft tubes of hydraulic turbines as so called vortex ropes resulting from spiral vortex breakdown. Moreover the situation can be complicated by cavitation within the core of the vortex. Paper presents various approaches, which were applied to enhance understanding of this problem. Numerical approach to study the linear stability including influence of cavitation is proposed and extensive nonlinear CFD simulations are described.

vírové proudění, kavitace, stabilita, rozpad víru

swirling flow, cavitation, stability, vortex breakdown

14.05.2012

Czech Society for Mechanics

Praha

978-80-86246-39-0

Book of Extended Abstracts

1

1123–1124

2