Ioan HOŢA


27-53 CONSIDERAŢII TEORETICE PRIVIND CALCULUL DE REZISTENŢĂ ŞI AL DEFORMAŢIILOR CAMERELOR ROTOARELOR TURBINELOR AXIALE ORIZONTALE (BULB)

THEORETICAL ASPECTS REGARDING THE STRENGTH CALCULATION AND THE DEFORMATIONS OF THE HORIZONTAL TURBINE RUNNER CHAMBERS
This paper presents main theoretical considerations regarding the strength calculation and the deformations of the horizontal axial turbine runner chambers – upstream bulb. The most suitable functional and constructive solutions – for those bulb turbines which designed at Hydro-Engineering, the runner chamber has the lower half embedded in the concrete, and the upper half of this is fixed through a bolted threaded connection and threaded studs. The strength calculation of the deformations is made only for the upper half of the runner chamber.
The establishment of the fundamental equations regarding the strength and deformation calculations have been made taking into account the theory of the plane and curved plates of S. Timoshenko. For solving the equations and avoiding the in determinations it has been used the energetic method (Castigliano’s method). Considering the stressing types that are applied to the upper half of the runner chamber in the paper, it is shown the forces and moments that is stressing the threaded connection of the upper half in relation to the lower half which embedded in the concrete
Keywords: turbine, runner, deformation, bulb
Cuvinte cheie: turbină, rotor, deformaţie, bulb

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27-48 ANALIZA EFECTULUI ROTIRII ÎN JURUL UNEI AXE A PALETELOR ROTORICE ALE TURBINELOR RAPIDE DE TIP FRANCIS ÎN VEDEREA MĂRIRII PERFORMANŢELOR ENERGO-CAVITAŢIONALE ALE ACESTORA

STUDY OF THE EFFECT OF THE FAST FRANCIS TURBINE BLADES’ SPIN AROUND AN AXIS, FOLLOWING CFD ANALYSIS OF FLOW AND RESULTS OF MEASUREMENTS IN THE LAB
The present paper propose an analysis of the rotation around an axis effect of the runner blades that compound the fast Francis turbines in order to increase their energo-cavitational performances. First step was done after the analysis of the runner which resulted from the calculations and hydro-dynamic design. This analysis was performed both theoretically using the finite element software package called CFX Blade Gen, and through experiment within the Test Laboratory for Hydraulic Turbines from Hydro-Engineering. Second step of the research consisted in rotating the blade around the axis with a certain angle in order to increase the absorbed flow, holding the rim and the ring from the initial blade. Rotating was performed in different angles by making the finite element analysis for all the rotating angles. In order to improve the cavitational component it was proposed and realized an extension of the blade with an appropriate covering degree, without any visible effect over the energetic features, these being maintained within the permitted error range that admitted by the IEC 60193 code.
Keywords: blade, runner, Francis
Cuvinte cheie: paleta, rotor, Francis

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