Water and Energy Abstracts
Year : 2004, Volume : 14, Issue : 1
First page : ( 43) Last page : ( 44)
Print ISSN : 0021-1672.

119. Stability of the Flow Through Pelton Turbine Nozzles

Dr. Vesely Jindoich, Prof. Pochyly Frantisek

(Proceedings, Hydro 2003, Vol. I, Croatia, pp. 147–156).

Abstract

The paper presents a study of flow stability in Pelton turbine nozzles. Theoretical background of stability flow analyses and numerical flow simulations describing this phenomenon are presented. A new practically applied solution of the flow stability increase is described and results of the model tests are presented in paper as well. Navier-Stokes equations are basic equations applied for describing flow through any geometrical area. These equations were used for describing the flow stability in common axisymmetric area. The flow through the Pelton turbine nozzle was numerically modelled as an axisymmeric flow to apply to below mentioned equations for flow stability description in axisymmetric area. By means of theoretical analysis the intensification of velocity perturbations in axisymmetric areas were studied. Some common criteria describing perturbation behaviour were evaluated and these criteria are discussed in context with flow through Pelton turbine nozzle. These criteria were modified to the form of easy equations. In case that the velocity distribution in studied area is known these equations could be evaluated and flow stability in Pelton turbine nozzle could be described by characteristic numbers only. Values of these numbers are some criteria of analysed Pelton turbine nozzle geometry from the view of absorbing of perturbation in the turbine nozzle. Theoretical investigation of the flow stability applied to flow in Pelton turbine nozzles appears as the realistic way for whole Pelton turbine efficiency increase. The stability of the flow at the nozzle outlet was improved after new theoretical result applications. A lot of new ideas directed to the flow stability in Pelton nozzles are open in the paper and some of them are answered.

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Keywords

Flow stability, Pelton, Simulations, Navier-stokes, Perturbation.

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