Investigating the influence of the jet from three nozzle and spear design configurations on Pelton runner performance by numerical simulation

Petley, Sean; Παναγιωτόπουλος, Αλέξανδρος; Benzon, D.; Židonis, Audrius; Aggidis, George A.; Anagnostopoulos, John S.; Papantonis, Dimitris

doi:10.1088/1755-1315/240/2/022004

Cited by 7 publications

(4 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(2011) compared the results for calculating buckets by experiment and Fluent, and found that the error between maximum efficiency and experimental value was 3.5%. Petley et al . (2019b) compared the numerical simulation and experimental data under different Pelton models by Fluent, and the efficiency error was between 1.4% and 1.6%.…”

Section: Discussionmentioning

confidence: 99%

SPH method used for characteristic predictions at Pelton turbine buckets: comparing with the mesh-based method

Sun

Zheng

2023

View full text Add to dashboard Cite

PurposeThe research in this paper helps to understand the difference between the Eulerian method and the Lagrangian method in describing the performance of Pelton turbine buckets, so as to improve the design level and design efficiency of the runner.Design/methodology/approachThis paper used DualSPHysics to calculate the unsteady flow of the Pelton turbine runner bucket and compared it with the mesh-based method to explore the difference between mesh-based and particle-based methods in torque curves, jet flow patterns and pressure characteristics.FindingsIt is noted that the particle-based method is challenging to compare with the mesh-based method concerning accuracy. In addition to better describing the free water film, the particle method also captures many droplets near the water film, but it cannot well describe the negative pressure region on the bucket back and the resulting jet interference after cutting off the jet. Compared with the mesh-based method, the pressure measurement points obtained by the particle-based method generally have shorter periods and violent fluctuations, and the pressure value of some points is underestimated.Originality/valueThis paper helped to calculate the unsteady characteristics of the Pelton turbine by Fluent, CFX and DualSPHysics; exploration jet flow pattern differences between the mesh and meshfree methods; prediction of the flow interference between the bucket back and the jet and the pressure curve of SPH usually has a shorter period and violent fluctuations.

show abstract

Section: Discussionmentioning

confidence: 99%

SPH method used for characteristic predictions at Pelton turbine buckets: comparing with the mesh-based method

Sun

Zheng

2023

View full text Add to dashboard Cite

show abstract

“…Meanwhile, the eccentric operation leads to an efficiency drop in the injector and the increasing of energy loss. Petley S et al [25] conducted a three-dimensional CFD numerical simulation of the interaction between the jet and the runner of a double-nozzle horizontal Pelton turbine, and they found that there was an optimal combination to maximize the operating efficiency of the turbine by changing the angle of the nozzle and the needle. Hahn et al [26] conducted numerical simulations of flow losses and secondary flows in the turbine flow tube and verified that the K-w shear stress transport model predicts head losses and secondary flows with high accuracy.…”

Section: Introductionmentioning

confidence: 99%

Nozzle Jet Deviation from Bucket Pitch Circle’s Effect on the Stability and Efficiency of Pelton Turbine

et al. 2023

View full text Add to dashboard Cite

During the operation of a Pelton turbine, the centerline of the nozzle jet may deviate from the bucket pitch circle due to the low installation and maintenance accuracy, which will reduce the operating efficiency and the stability of the turbine and even cause severe vibrations and damages. Based on the VOF (Volume of Fluid) two-phase flow model and the SST k-ω turbulence model, the flow characteristics of a Pelton turbine were simulated with the nozzle jet deviating from the bucket pitch circle. The pressure pulsation inside the bucket and the force distribution of the runner were obtained, the turbine oscillation and efficiency were measured before and after the jet deviation, and the effects of the radial and axial deviations on the stability and efficiency of the Pelton turbine were analyzed. The results show that both the radial and axial deviations of the jet cause a significant increase in the axial force and the pressure pulsation amplitude of the turbine; the radial and tangential forces on the runner are slightly reduced; the maximum axial force on the runner is increased by 4 times and 2 times, respectively, after the axial and radial deviations within the maximum value allowed by the industry standard; and the efficiency of the turbine is reduced by 0.4% and 0.3%, respectively. The maximum relative amplitude of pressure pulsation in the radial offset case appears in the center of the bucket blade, while the axial offset case causes uneven pressure distribution on both sides of the diverter blade, uneven force on the bucket blade of the runner, and fatigue damage. By comparing the operation of the runner under the two offset cases, we can find that the axial offset of the jet has a greater impact on the stability of the runner than the radial offset, and the unit is more prone to vibration, increasing the risk of the unit lifting.

show abstract

“…Petley at al. [11] experimented and simulated how the nozzle and spear valve configuration affect the performance of a Pelton turbine. Even though numerical simulations showed higher performance in injector with notably steeper nozzle, experimental data suggested that an upper limit appears beyond which steeper angles designs are no longer optimal.…”

Section: Introductionmentioning

confidence: 99%

Laser Doppler Anemometry technique to study the flow field in the nozzle and in the water jet of a Pelton turbine

Pisaturo,

Nicolosi,

Gusmerotti

et al. 2023

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

The constant availability of water from the mountain basins is crucial to feed the hydropower plants that currently represent the most important renewable energy source in many countries, like Italy. The long dry periods that are nowadays registered during the summer periods have imposed the managers of the hydropower plants to operate the machines at very low flow rates, close to the lowest allowed values. In this work we focus our attention on the fluid-dynamics of the water jet of a Pelton machine and of the corresponding nozzle, with particular attention to the low flow-rate ranges. The nozzle has been manufactured in PMMA to be able to study the internal fluid-dynamics using the Laser Doppler Anemometry (LDA) technique. The shape of the nozzle has been adapted to limit the laser beam distortion and an algorithm has been implemented to correct the position of the measurement volume and the evaluation of the velocity components. Moreover, a specific measurement layout has been proposed and implemented to be able to study the velocity of the water jet downstream the nozzle and to study the homogeneity of the flow velocity in the jet, which is a crucial characteristic to grant a proper operation of the Pelton runner. The specific set-up of the test bench and the LDA parameters are presented; the signal of the LDA receiver proved to be very consistent and reliable. Moreover, the results of the measurements have been used to validate CFD simulations and to extend the results of the analyses to other operating conditions of the Pelton nozzle

show abstract

Investigating the influence of the jet from three nozzle and spear design configurations on Pelton runner performance by numerical simulation

Cited by 7 publications

References 5 publications

SPH method used for characteristic predictions at Pelton turbine buckets: comparing with the mesh-based method

SPH method used for characteristic predictions at Pelton turbine buckets: comparing with the mesh-based method

Nozzle Jet Deviation from Bucket Pitch Circle’s Effect on the Stability and Efficiency of Pelton Turbine

Laser Doppler Anemometry technique to study the flow field in the nozzle and in the water jet of a Pelton turbine

Contact Info

Product

Resources

About