A Review of Available Methods for the Assessment of Fluid Added Mass, Damping, and Stiffness With an Emphasis on Hydraulic Turbines

2018 ◽  
Vol 70 (5) ◽  
Author(s):  
Arash Soltani Dehkharqani ◽  
Jan-Olov Aidanpää ◽  
Fredrik Engström ◽  
Michel J. Cervantes
Keyword(s):  
Three Dimensional ◽  
Added Mass ◽  
Literature Survey ◽  
Francis Turbine ◽  
Three Dimensional Flow ◽  
Experimental Approaches ◽  
Complex Fluid ◽  
Hydraulic Turbines ◽  
The Impact ◽  
Fluid Added Mass

Fluid added mass, damping, and stiffness are highly relevant parameters to consider when evaluating the dynamic response of a submerged structure in a fluid. The prediction of these parameters for hydraulic turbines has been approached relatively recently. Complex fluid-structure analyses including three-dimensional flow and the need for experiments during operation are the main challenges for the numerical and experimental approaches, respectively. The main objective of this review is to address the impact of different parameters, for example, flow velocity, cavitation, nearby solid structure, and rotational speed on the fluid added mass and damping of Kaplan/Propeller and Francis turbine runners. The fluid added stiffness is also discussed in the last section of the paper. Although studies related to hydraulic turbines are the main objective of this paper, the literature on hydrofoils is also taken into consideration to provide valuable information on topics such as individual runner blades. In this literature survey, the analytical, numerical, and experimental approaches used to determine fluid added parameters are discussed, and the pros and the cons of each method are addressed.

Prediction of Particle Impact on an Archimedes Screw Runner Blade for Micro Hydro Turbine

2013 ◽  
Vol 465-466 ◽  
pp. 552-556
Author(s):  
Muhammad Ammar Nik Mutasim ◽  
Nurul Suraya Azahari ◽  
Ahmad Alif Ahmad Adam
Keyword(s):  
Three Dimensional ◽  
Leading Edge ◽  
Navier Stokes ◽  
Particle Impact ◽  
Three Dimensional Flow ◽  
Navier Stokes Equation ◽  
Runner Blade ◽  
Computational Fluid Dynamics Cfd ◽  
The Subject ◽  
The Impact

Energy is one of the most important sources in the world especially for developing countries. The subject study is conducted to predict the behaviour of particle due to errosion from the river through the achimedes screw runner and predict the impact of particle toward blade surface. For this reason, computational fluid dynamics (CFD) methods are used. The three-dimensional flow of fluid is numerically analyzed using the Navier-Stokes equation with standard k-ε turbulence model. The reinverse design of archimedes screw blade was refered with the previous researcher. Flow prediction with numerical results such as velocity streamlines, flow pattern and pressure contour for flow of water entering the blade are discussed. This study shows that the prediction of particle impact occurs mostly on the entering surface blade and along the leading edge of the screw runner. Any modification on the design of the screw runner blade can be analyze for further study.

Numerical simulation of fluid added mass effect on a francis turbine runner

2007 ◽  
Vol 36 (6) ◽  
pp. 1106-1118 ◽  
Author(s):  
Q.W. Liang ◽  
C.G. Rodríguez ◽  
E. Egusquiza ◽  
X. Escaler ◽  
M. Farhat ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Mass Effect ◽  
Added Mass ◽  
Francis Turbine ◽  
Turbine Runner ◽  
Fluid Added Mass

CFD Performance Evaluation and Runner Blades Design Optimization in a Francis Turbine

2009 ◽  
Author(s):  
Jose Manuel Franco-Nava ◽  
Erik Rosado-Tamariz ◽  
Oscar Dorantes-Gomez ◽  
Jose´ Manuel Ferna´ndez-Da´vila ◽  
Reynaldo Rangel-Espinosa
Keyword(s):  
Measurement System ◽  
Three Dimensional ◽  
Hydrodynamic Performance ◽  
Francis Turbine ◽  
Computational Domain ◽  
Coordinate Measurement ◽  
Spiral Case ◽  
Hydraulic Turbines ◽  
Optimization Methodology ◽  
Artificial Neural Network Ann

The application of computational fluid dynamics (CFD) in the redesign or rehabilitation of hydraulic turbines appears to be necessary in order to improve their efficiency and cost-effectiveness beyond the traditional redesign practices. The runner geometry considered within the computational domain was modelled by using a three-dimensional laser triangulation scanner coupled with a portable coordinate measurement system. The runner geometry was generated by a number of 3D sub models, one for each of the main components of the runner, crown, band and a blade. In order to obtain a blade geometry a portable coordinate measurement system based on optical digitalization technology (scanner technology) was used. A numerical optimization methodology is developed and applied to a Francis turbine. The hydrodynamic performance analysis was investigated by application of a three dimensional Navier-Stoke commercial turbomachinery oriented CFD code. Analysis of the flow through the spiral case and stay vanes was carried out so as to include appropriate flow effects induced by these components and boundary conditions at the inlet of the wicket. A CFD analysis for the wicket and runner was carried out to generate the so called reference solution. Then, the runner blades design was optimized by a process implemented in a commercial CFD code which combines genetic algorithms and a trained artificial neural network (ANN). A database of geometries and their respective CFD computations were computed in order to determine the optimum geometry for a given objective function. The flow within hydraulic turbines has a thin boundary layer and noticeable pressure gradients. Hence, the CFD computations were carried out using the Sparlat-Allmaras turbulence model. After optimization cycle convergence, an increment not only in efficiency but also in power was obtained. The optimized runner represented by a parametric model achieves considerably higher efficiency than the reference runner. Efficiency versus power curve was used to compare data from measurements at the power station for the reference runner versus the parametric optimized runner model. Results have shown that application of CFD based optimization can modify and improve runners design so as to increase the efficiency and power of installed hydraulic power stations.

Three-Dimensional Flow in an Axial Turbine: Part 2—Profile Attenuation

1992 ◽  
Vol 114 (1) ◽  
pp. 71-78 ◽  
Author(s):  
D. Joslyn ◽  
R. Dring
Keyword(s):  
Temperature Profile ◽  
Three Dimensional ◽  
Inlet Temperature ◽  
Three Dimensional Flow ◽  
Turbine Inlet Temperature ◽  
Axial Turbine ◽  
Physical Mechanisms ◽  
Dimensional Flow ◽  
Surface Measurements ◽  
The Impact

This paper presents an exhaustive experimental documentation of the three-dimensional nature of the flow in a one-and-one-half stage axial turbine. The intent was to examine the flow within, and downstream of, both the stator and rotor airfoil rows so as to delineate the dominant physical mechanisms. Part 1 of this paper presented the aerodynamic results. Part 2 presents documentation of the mixing, or attenuation, of a simulated spanwise inlet temperature profile as it passed through the turbine, including: (1) the simulated combustor exit-turbine inlet temperature profile, (2) surface measurements on the airfoils and endwalls of the three airfoil rows, and (3) radial–circumferential distributions downstream of each airfoil. Although all three rows contributed to profile attenuation, the impact of the rotor was strongest.

scholarly journals Supercritical flow at an abrupt drop: flow patterns and aeration

1998 ◽  
Vol 25 (5) ◽  
pp. 956-966 ◽  
Author(s):  
H Chanson ◽  
L Toombes
Keyword(s):  
Shock Waves ◽  
Open Channel ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Flow Patterns ◽  
Three Dimensional Flow ◽  
Supercritical Flow ◽  
Drop Flow ◽  
Supercritical Flows ◽  
The Impact

Stepped waterways and cascades are common features of storm waterways, at dam outlets, and in water treatment plants. At an abrupt drop, open channel flows are characterized by the presence of shock waves and a substantial flow aeration. There is, however, little information on the basic flow characteristics. The study presents new experimental data obtained in a 0.5-m-wide stepped flume with an unventilated nappe. The investigations describe the three-dimensional flow patterns, including shock waves, standing waves, and spray, downstream of the nappe impact. The characteristics of the flow patterns are similar to those observed with abrupt expansion supercritical flows. Downstream of the drop brink, substantial aeration takes place along the nappe interfaces and the flow downstream of the impact is deaerated.Key words: abrupt drop, supercritical flow, shock waves, flow patterns, cascade.

Three-Dimensional Flow in an Axial Turbine: Part 2 — Profile Attenuation

1990 ◽  
Author(s):  
David Joslyn ◽  
Robert Dring
Keyword(s):  
Temperature Profile ◽  
Three Dimensional ◽  
Inlet Temperature ◽  
Three Dimensional Flow ◽  
Turbine Inlet Temperature ◽  
Axial Turbine ◽  
Physical Mechanisms ◽  
Dimensional Flow ◽  
Surface Measurements ◽  
The Impact

This paper presents an exhaustive experimental documentation of the three–dimensional nature of the flow in a one–and–one–half stage axial turbine. The intent was to examine the flow within, and downstream of, both the stator and rotor airfoil rows so as to delineate the dominant physical mechanisms. Part 1 of this paper presented the aerodynamic results. Part 2 presents documentation of the mixing, or attenuation, of a simulated spanwise inlet temperature profile as it passed through the turbine including: (1) the simulated combustor exit–turbine inlet temperature profile, (2) surface measurements on the airfoils and endwalls of the three airfoil rows, and (3) radial–circumferential distributions downstream of each airfoil. Although all three rows contributed to profile attenuation, the impact of the rotor was strongest.

Experimental Investigation of Heat Transfer on the Internal Tip Wall in a Rotating Two-Pass Rectangular Channel

2019 ◽  
Author(s):  
Kai-Chieh Chia ◽  
Szu-Chi Huang ◽  
Yao-Hsien Liu
Keyword(s):  
Heat Transfer ◽  
Channel Wall ◽  
Rectangular Channel ◽  
Three Dimensional ◽  
Internal Cooling ◽  
Cooling Channel ◽  
Three Dimensional Flow ◽  
Smooth Channel ◽  
Blade Tip ◽  
The Impact

Abstract The current study experimentally studied heat transfer characteristics of the blade tip wall in a rotating internal cooling channel. The aspect ratio of this rectangular channel was 1:4, and the hydraulic diameter was 25.6 mm. Due to the impact of the 180° turn, complex three dimensional flow significantly affected heat transfer on the internal tip surface. The liquid crystal method is used to capture the heat transfer contour on the internal tip surface. In this study, the leading and trailing surfaces of the channel wall were either smooth or roughened with 45° angled ribs. The Reynolds number inside the pressurize two-pass cooling channel ranged from 10,000 to 30,000 at both stationary and rotating conditions. Furthermore, two channel orientations (90° and 135°) were tested. The effect of Coriolis force on heat transfer is studied with the rotation number up to 0.53. The tip heat transfer from the smooth channel wall was more sensitive to rotation and the largest heat transfer enhancement as a result of rotation was 68%.

Hydraulic turbines—basic principles and state-of-the-art computational fluid dynamics applications

1999 ◽  
Vol 213 (1) ◽  
pp. 85-102 ◽  
Author(s):  
P Drtina ◽  
M Sallaberger
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
State Of The Art ◽  
Three Dimensional ◽  
Hydraulic Turbine ◽  
Francis Turbine ◽  
Basic Principles ◽  
Vast Number ◽  
Basic Fluid ◽  
Hydraulic Turbines

The present paper discusses the basic principles of hydraulic turbines, with special emphasis on the use of computational fluid dynamics (CFD) as a tool which is being increasingly applied to gain insight into the complex three-dimensional (3D) phenomena occurring in these types of fluid machinery. The basic fluid mechanics is briefly treated for the three main types of hydraulic turbine: Pelton, Francis and axial turbines. From the vast number of applications where CFD has proven to be an important help to the design engineer, two examples have been chosen for a detailed discussion. The first example gives a comparison of experimental data and 3D Euler and 3D Navier-Stokes results for the flow in a Francis runner. The second example highlights the state-of-the-art of predicting the performance of an entire Francis turbine by means of numerical simulation.

Simulation of Wind Environment around a Commercial Complex Building in Shenyang China

2013 ◽  
Vol 353-356 ◽  
pp. 3717-3721
Author(s):  
Xiao Ming Zhang ◽  
Bo Li ◽  
Xiao Zhang
Keyword(s):  
Fluid Dynamics ◽  
Wind Speed ◽  
Three Dimensional ◽  
Differential Pressure ◽  
Three Dimensional Flow ◽  
Wind Environment ◽  
Shenyang City ◽  
Complex Building ◽  
Under Construction ◽  
The Impact

The pedestrian safety and comfort is closely related to the wind environment around the commercial complex building. In this paper, we simulate the steady-state three-dimensional flow field around a commercial complex building which is still under construction in Shenyang city by using CFD (Computational Fluid Dynamics) software. The distribution of wind speed and pressure around the commercial complex are obtained. In summer wind speed around complex is 0.5-3.6 m/s and the differential pressure greater than 1.5 Pa under the dominant wind. In winter wind speed is 0.5-4 m/s and the differential pressure less than 5 Pa except windward under the dominant wind. Local vortex appeared in both summer and winter due to the shape of complex building. The commercial complex building also had an impact on the wind environment of the surrounding buildings, larger the building, greater the impact.

scholarly journals Quasi-Three-Dimensional and Three-Dimensional Flow Calculation in a Francis Turbine

1996 ◽  
Author(s):  
Manfred J. Sallaberger
Keyword(s):  
Incompressible Flow ◽  
Draft Tube ◽  
Three Dimensional ◽  
Computational Method ◽  
Francis Turbine ◽  
Governing Equations ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Specific Speed ◽  
Double Grid

The complex three-dimensional flow in the wicket gate and the runner of a Francis turbine is investigated by applying both a quasi-three-dimensional and a three-dimensional computational method. The computations were conducted on a double grid containing the stationary wicket gate and the rotating runner. The equations for inviscid and incompressible flow are solved, assuming that the relative flow field in the runner is stationary. In the quasi-three-dimensional method the governing equations are solved on stream surfaces using a Finite-Element-Method. In the three-dimensional method, the equations of continuity and motion are solved by a Finite-Volume technique using Denton’s code for incompressible flow. Both methods are used in order to compute the flow in a Francis-runner of high specific speed at the operating point of optimum efficiency. The results of the calculations are compared with measurements taken at the draft-tube inlet. Differences between results of computations and measurements are presented.

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