High Speed Flow Visualisation of an Impinging Jet on a Pelton Turbine Bucket

Perrig, Alexandre; Farhat, Mohamed; Avellan, François

doi:10.1115/fedsm2007-37628

Cited by 11 publications

(15 citation statements)

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“…Indeed, the 3D vertical velocity profiles are quite different from the 3D horizontal or the 2D axisymmetric showing clear deviation from the axis. This deviation is most probably caused by the bend upstream of the nozzle and has been observed by other researchers [4,5]. The change of flow direction creates a pair of counter-rotating secondary flow vortices (Dean vortices), which are established above the spear shaft, as shown in Fig.…”

Section: Stand-alone Injector Comparisonmentioning

confidence: 80%

“…An optimised design was created with nozzle and spear angles of 110° and 70° compared to the standard 90° and 50° nozzle and spear angles. In the present study these two injectors are compared further by including the pipework and spear holding vanes upstream of the injectors which have been shown to add disturbances to the jet [4]. The 3D jet profiles produced by these simulations are then imported into the full Pelton and Turgo runner simulations and used to compare the performance of each injector design.…”

Section: Introductionmentioning

confidence: 99%

“…Due to the high complexity and unsteadiness of the flow during jet-runner interaction, the development of impulse turbines is difficult and requires sophisticated equipment for flow observation [4][5][6][7] or high cost computational resources for accurate numerical analysis [8][9][10][11][12][13][14][15][16]. There are some studies available where a selection of injector designs are modelled and compared using CFD [17][18][19] or using a visual analysis [20][21][22].…”

Section: Introductionmentioning

confidence: 99%

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Numerical Investigation of the Spear Valve Configuration on the Performance of Pelton and Turgo Turbine Injectors and Runners

Benzon

Židonis

Παναγιωτόπουλος

et al. 2015

Journal of Fluids Engineering

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This paper uses two modern commercial CFD software packages to compare the performance of a standard and improved impulse turbine injector developed in a previous study. The two injector designs are compared by simulating the 2D axis-symmetric cases as well as full 3D cases including the bend in the branch pipe and the guide vanes. The resulting jet profiles generated by these simulations are used to initialise the inlet conditions for a full Pelton and Turgo runner simulation at different operating conditions in order to assess the impact of the injector design on the performance and efficiency of a real impulse turbine.The results showed that the optimised injector design, with steeper nozzle and spear angles, not only attains higher efficiencies in the 2D and 3D injector simulations, but produces a jet which performs better than the standard design in both the Pelton and the Turgo runner simulations. The result show that the greatest improvement in the hydraulic efficiency occurs within the injector with the improved design showing an increase in efficiency of 0.76% for the Turgo 3D injector and 0.44% for the Pelton 3D injector. The results also show that in the case of the 3D injector, the improved injector geometry produces a jet profile which induces better overall runner performance, giving a 0.5% increase in total hydraulic efficiency for the Pelton case and 0.7% for the Turgo case.

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Section: Stand-alone Injector Comparisonmentioning

confidence: 80%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Numerical Investigation of the Spear Valve Configuration on the Performance of Pelton and Turgo Turbine Injectors and Runners

Benzon

Židonis

Παναγιωτόπουλος

et al. 2015

Journal of Fluids Engineering

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“…Perrig et al [1,2] used flow observation techniques to study the unsteady evolution of the free-surface flow in a single-injector Pelton runner. They found that the impact of the droplets released from the buckets causes perturbations on the jet surface, which may result in reduced bucket efficiency.…”

Section: Introductionmentioning

confidence: 99%

“…The high complexity of the unsteady jet-bucket interaction in the rotating runner and, moreover, the contaminating effects of the outflow that splashes on the casing walls make the measurements of the flow in the interior of the casing practically impossible. Hence, the existing experimental works concern either flow visualization studies [1,2] or flow-bucket interaction in non-rotating buckets [3,4].…”

Section: Introductionmentioning

confidence: 99%

Performance measurements on a Pelton turbine model

Stamatelos

Anagnostopoulos

Papantonis

2011

Proceedings of the Institution of Mechanical Engineers, Part A:

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Pelton hydraulic turbines are impulse-type turbomachines commonly used in hydroelectric plants with medium-to-high water head and in various energy recovery applications. The aim of the present work is to provide detailed performance measurements on a Pelton turbine model, along with the design and geometrical dimensions of its runner/buckets and injectors. Such a complete set of data would be useful for further development and evaluation of numerical modelling tools of the complex unsteady free-surface flow developed in the turbine, and is missing from the literature. The two-nozzle Pelton model was designed using standard guidelines and was fully constructed in the Laboratory of Hydraulic Turbomachines, NTUA. The measurements include the net water head and flowrate, the injector characteristic curves, and the torque and rotation speed of the runner, from which the corresponding overall efficiency and shaft power are computed. The model was tested with one injector (upper or lower) and with both injectors in operation, using either constant or variable rotation speed mode. The comparative results were satisfactory and in line with the theory, verifying similarity and repeatability, and allowing for an estimation of mechanical losses. The measurements covered the entire operation range of the turbine, in order to draw complete hillcharts for various operation modes.

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Review on erosion phenomenon, maintenance, and financial calculation of lifetime as an asset for Pelton turbines

Abregu,

Acharya,

Solemslie

2023

J. Phys.: Conf. Ser.

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Prevention of greenhouse emissions is the top priority for all countries, which urges them to switch to renewable energy as much as possible. Hydropower is one of the renewables that have high flexibility and at the same time compatibility to be used with any other renewable sources. Moreover, hydropower plants operating in the Himalayas, Andes, and Alps are facing operational challenges due to the high concentration of sediment loads in rivers. Although the arrangement of traditional sediment control mechanisms like dams and sand traps, the erosion tendency of hydro-turbine components operating in this sediment-laden water increases with the increased concentration of sediments. Much past research has been directed towards understanding sediment behaviors, investigation of flow, and effect of concentration, shape, and size, especially with Francis turbines. However, there are very fewer studies regarding sediment erosion and flow behavior in the case of the Pelton turbine. Hence, delving deeper into the flow characteristics, sediment behavior, and performance of the Pelton turbine is important to better understand the flow and sediment pattern of these types of turbines. The paper consists of the evaluation of studies conducted on the flow pattern in the Pelton turbine buckets and its validation with the numerical analysis models using image processing. It is being used in the Waterpower Laboratory at the Norwegian University of Science and Technology, NTNU. This paper also evaluates the scope of investigations about erosion by sediments in Pelton buckets using image analysis and state-of-the-art technology in the hydropower sector. In addition, a review is done about the predictability of erosion based on the measurements of the quantity of sediments that passes through the turbine. This research paper can build a background for quantifying sediment erosion in Pelton turbines with a certain degree of error, which can be utilized as a reference in future studies. The life cycle estimation of a turbine is also analyzed with the consideration of its location and financial return requirements together with the type of maintenance that it may have and the repair that is foreseen, in the case of a non-coated surface.

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High Speed Flow Visualisation of an Impinging Jet on a Pelton Turbine Bucket

Cited by 11 publications

References 1 publication

Numerical Investigation of the Spear Valve Configuration on the Performance of Pelton and Turgo Turbine Injectors and Runners

Numerical Investigation of the Spear Valve Configuration on the Performance of Pelton and Turgo Turbine Injectors and Runners

Performance measurements on a Pelton turbine model

Review on erosion phenomenon, maintenance, and financial calculation of lifetime as an asset for Pelton turbines

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