Numerical investigation of the interaction between jet and bucket in a Pelton turbine

2009 ◽  
Vol 223 (6) ◽  
pp. 721-728 ◽  
Author(s):  
A Santolin ◽  
G Cavazzini ◽  
G Ardizzon ◽  
G Pavesi
Keyword(s):  
Experimental Data ◽  
Numerical Analysis ◽  
Detailed Analysis ◽  
Numerical Investigation ◽  
Two Phase ◽  
Pelton Turbine ◽  
Inhomogeneous Model ◽  
The North ◽  
Hydraulic Machines ◽  
Single Jet

This article presents the numerical investigation of the interaction between the jet and the bucket in a Pelton turbine. Unsteady numerical analyses were carried out on a single jet Pelton turbine installed in the north of Italy. A two-phase inhomogeneous model was used. Two different jet configurations were analysed and compared. In the first configuration, the interaction between the runner and an axial-symmetric jet characterized by a given velocity jet profile was investigated, whereas in the second configuration the runner was coupled with the needle nozzle and the final part of the penstock and the interaction between the jet and the bucket was analysed. A detailed analysis of the torque highlighted the influence of the shape of the water jet on the turbine losses and the influence of the stator on the efficiency of this type of hydraulic machines was shown. The numerical results were compared with the experimental data derived from the installation test of the turbine in order to validate the numerical analysis.

Establishment and verification of a contact model of flowing fresh concrete

2018 ◽  
Vol 35 (7) ◽  
pp. 2589-2611
Author(s):  
Yuan Zhao ◽  
Zhennan Han ◽  
Yali Ma ◽  
Qianqian Zhang
Keyword(s):  
Experimental Data ◽  
Numerical Analysis ◽  
Fresh Concrete ◽  
Dynamic Performance ◽  
Discrete Element ◽  
Contact Model ◽  
Two Phase ◽  
Content Type ◽  
Concrete Pumping ◽  
Contact Models

Purpose The purpose of this paper is to establish a new dynamic coupled discrete-element contact model used for investigating fresh concrete with different grades and different motion states, and demonstrate its correctness and reliability according to the rheological property results of flow fresh concrete in different working states through simulating the slump process and mixing process. Design/methodology/approach To accurately express the motion and force of flowing fresh concrete in different working states from numerical analysis, a dynamic coupled discrete-element contact model is proposed for fresh concrete of varying strength. The fluid-like fresh concrete is modelled as a two-phase fluid consisting of mortar and aggregate. Depending on the contact forms of the aggregate and mortar, the model is of one of the five types, namely, Hertz–Mindlin, pendular LB contact, funicular mucous contact, capillary LB contact or slurry lift/drag contact. Findings To verify the accuracy of this contact model, concrete slump and cross-vane rheometer tests are simulated using the traditional LB model and dynamic coupled contact model, for five concrete strengths. Finally, by comparing the simulation results from the two different contact models with experimental data, it is found that those from the proposed contact model are closer to the experimental data. Practical implications This contact model could be used to address issues such as (a) the mixing, transportation and pumping of fresh concrete, (b) deeper research and discussion on the influence of fresh concrete on the dynamic performance of agitated-transport vehicles, (c) the behaviour of fresh concrete in mixing tanks and (d) the abrasion of concrete pumping pipes. Originality/value To accurately express the motion and force of flowing fresh concrete in different working states from numerical analysis, a dynamic coupled discrete-element contact model is proposed for fresh concrete of varying strength.

Numerical Prediction of Efficiency, Cavitation and Unsteady Phenomena in Water Turbines

2008 ◽  
Author(s):  
Dragica Josˇt ◽  
Andrej Lipej ◽  
Peter Mezˇnar
Keyword(s):  
Steady State ◽  
Numerical Analysis ◽  
Detailed Analysis ◽  
Computer Code ◽  
Second Step ◽  
Piping System ◽  
Steady State Analysis ◽  
Pelton Turbine ◽  
Ansys Cfx ◽  
Water Turbines

The paper presents numerical analysis of the flow in all types of water turbines. Analysis was performed by ANSYS CFX-11.0 computer code. A detailed analysis of complete radial and axial turbine is presented. On the basis of numerical results efficiency and cavitation are predicted and compared to the measured results obtained on test rigs in Turboinstitut. The paper presents also numerical analysis of the flow in a two jet Pelton turbine. The analysis was divided into two parts. At first a steady state analysis of the flow in the piping system with the jets at the outlet was performed. The second step was unsteady analysis of the runner with jets. The casing was not included in the domain of calculation. The predicted efficiency is compared to the measured values.

NUMERICAL INVESTIGATION OF SUPERCOOLED DROPLETS IMPINGEMENT ON COMPLICATED ICING SURFACE

2009 ◽  
Vol 23 (03) ◽  
pp. 469-472
Author(s):  
DALIN ZHANG ◽  
WEIJIAN CHEN
Keyword(s):  
Experimental Data ◽  
Numerical Investigation ◽  
Phase Model ◽  
Effective Algorithm ◽  
Aircraft Icing ◽  
Two Phase ◽  
Droplet Impingement ◽  
Eulerian Method ◽  
Weakly Coupled ◽  
Droplet Flows

The supercooled droplet impingement on complicated icing surface has been investigated with the Eulerian method. A simplified air/droplet two-phase model is established, and an effective algorithm is proposed to deal with the dilute, weakly coupled air/droplet flows for aircraft icing problem. An Eulerian droplets computation code has been developed and validated with the iced NACA23012, and the results agree well with the experimental data. Meanwhile, compared with the results from the traditional Lagrangian method, it indicates that the Eulerian method gives a better prediction when the multiple impingement zones occur on complicated icing surface.

scholarly journals Flow Analysis Inside a Pelton Turbine Bucket

2006 ◽  
Vol 128 (3) ◽  
pp. 500-511 ◽  
Author(s):  
B. Zoppé ◽  
C. Pellone ◽  
T. Maitre ◽  
P. Leroy
Keyword(s):  
Numerical Analysis ◽  
Flow Analysis ◽  
Flow Volume ◽  
Volume Of Fluid Method ◽  
Two Phase ◽  
Pelton Turbine ◽  
Wide Range ◽  
Good Consistency ◽  
Turbine Bucket ◽  
Insight Into

The aim of this work is to provide a detailed experimental and numerical analysis of the flow in a fixed bucket of a Pelton turbine. The head, jet incidence, and flow rate have been varied to cover a wide range of the turbine functioning points. The experimental analysis provides measurements of pressure and torque as well as flow visualization. The numerical analysis is performed with the FLUENT code using the two-phase flow volume of fluid method. The results present a good consistency with experimental data. In particular, the pressure distribution is very well predicted for the whole range of the studied parameters. A detailed analysis of torque and thrust allows evaluating the losses due to the edge and the cutout of the bucket. These results give insight into the benefit we can expect of steady flow calculations through the optimization process of the design of Pelton turbines.

scholarly journals Numerical analysis of the electrospinning process for fabrication of composite fibers

2020 ◽  
Vol 24 (4) ◽  
pp. 2377-2383
Author(s):  
Adnan Ahmed ◽  
Lan Xu
Keyword(s):  
Experimental Data ◽  
Numerical Analysis ◽  
Flow Velocity ◽  
Composite Fiber ◽  
Electrospinning Process ◽  
Phase Flow ◽  
Composite Fibers ◽  
Two Phase ◽  
Fiber Process ◽  
Multi Phase

An electrospun composite fiber process is a multi-phase and multi-physics process. It was very difficult to study a charged jet in the electrospinning process for the fabrication of composite fibers by experiments. In this study, the liquid-solid two-phase flow in the electrospinning process for fabrication of composite fibers was researched numerically. The results showed the addition of conductive nanoparticles resulted in the increase of the jet flow velocity, and the decrease of the fiber?s diameter. The CFD results corresponded well with the experimental data.

scholarly journals Performance of Inclined Skirt Footing: Numerical Analysis

2021 ◽  
Vol 889 (1) ◽  
pp. 012076
Author(s):  
Chamjeet Singh ◽  
Jagdeep Singh ◽  
Sandeep Singh ◽  
Vikas Kumar
Keyword(s):  
Experimental Data ◽  
Numerical Analysis ◽  
Bearing Capacity ◽  
Numerical Investigation ◽  
Sandy Soil ◽  
Load Capacity ◽  
Strip Footing ◽  
Shallow Foundation ◽  
Deep Foundation ◽  
Inclined Load

Abstract The skirt footings are considered as alternate to enhance the bearing capacity of shallow foundation on sandy soil as an alternate of deep foundation. The experimental data of paper titled “Performance of skirt strip footing subjected to eccentric inclined load was consider as base for validation and other parameters of material for numerical investigation for different conditions. Numerical analysis was conducted to determine the behavior of two-sided skirt footing on eccentric loading with different angle and projections provided to skirt. The study reveals good impact of skirt angle and skirt projection lengths on load capacity of footing system

NUMERICAL ANALYSIS OF DUAL TWO-PHASE DISCHARGE FROM A HEADER

2018 ◽  
Author(s):  
M. K. Guyot ◽  
Scott J. Ormiston ◽  
Hassan M. Soliman
Keyword(s):  
Numerical Analysis ◽  
Two Phase
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