scholarly journals Three-Dimensional Inverse Design of Low Specific Speed Turbine for Energy Recovery in Cooling Tower System

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3348
Author(s):  
Wei Yang ◽  
Xiaoyu Lei ◽  
Benqing Liu
Keyword(s):  
Response Surface ◽  
Three Dimensional ◽  
Inverse Design ◽  
Design Parameters ◽  
Design Criteria ◽  
Blade Loading ◽  
Turbine Runner ◽  
Lean Angle ◽  
Low Specific Speed ◽  
Specific Speed

A three-dimensional inverse design of a low specific speed turbine is studied, and a set of design criteria for low specific speed turbine runner is proposed, including blade loading distributions and blade lean angles. The characteristics of the loading parameters for low specific speed turbine runner are summarized by analyzing the suction performance of different loading positions, loading slopes and blade lean angles based on the orthogonal experiment design and range analysis. It is found that the blade loading distribution at the band plays a more important role than it does at the crown and it should be fore loaded for both band and crown. The blade lean angle at the blade leading edge should be negative. Then, the blade is optimized through the inverse method by fixing blade lean angle, based on the response surface method. After seeking the optimal value of the response surface function, the optimal result of the design parameters is obtained, which is in conformity with the design criteria and verifies the rationality of the established design criteria for low specific speed turbine.

Redesign of a Transonic Compressor Rotor by Means of a Three-Dimensional Inverse Design Method: A Parametric Study

2007 ◽  
Author(s):  
Duccio Bonaiuti ◽  
Abeetha Pitigala ◽  
Mehrdad Zangeneh ◽  
Yansheng Li
Keyword(s):  
Design Method ◽  
Thickness Distribution ◽  
Three Dimensional ◽  
Tip Clearance ◽  
Inverse Design ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Blade Loading ◽  
Inverse Design Method ◽  
The Impact

In the present paper, the redesign of a transonic rotor was performed by means of a three-dimensional viscous inverse design method. The inverse approach used in this work is one where the pressure loading, blade thickness distribution and stacking axis are specified and the camber surface is calculated accordingly. The design of transonic and supersonic axial compressors strongly relies on the ability to control the shock strength, location and structure. The use of an inverse design method allows one to act directly on aerodynamic parameters, like the blade loading, and provides an efficient tool to control the shock wave and its interaction with the boundary and secondary flows and with the tip clearance vortex. In the present study, the parametric investigation of the blade loading distribution was carried out. Few design parameters, with immediate physical meaning, were required to control the three-dimensional blade loading, and their impact on the design and off-design performance of the rotor was assessed by means of CFD calculations. Further investigations were then performed in order to study the impact on the rotor performance of the geometrical parameters (meridional channel and thickness distribution), which must be imposed in the design with the inverse method. As a result, it was possible to develop guidelines for the aerodynamic design of transonic rotors that can be exploited for similar design applications.

The Radial Turbine, for Low Specific Speeds and Low Velocity Factors

1961 ◽  
Vol 83 (1) ◽  
pp. 1-8 ◽  
Author(s):  
E. M. Knoernschild
Keyword(s):  
Three Dimensional ◽  
Efficiency Improvement ◽  
Low Velocity ◽  
Blade Loading ◽  
Turbine Performance ◽  
Radial Turbine ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Turbine Design ◽  
Radial Turbines

The main factors which influence radial-turbine performance are discussed. After a short description of the losses in radial turbines, the concept of the diffusion parameter is introduced. It is shown how the turbine geometry influences performance and, in particular, the reaction. The influence of a variation of the reaction on performance of radial turbines with high and low specific speed is discussed. Three-dimensional effects appear especially in the exducer region of the turbine. They may contribute to backflow and to a distorted distribution of the meridional velocity. The basic approach to improving turbines in the range of low-velocity factors and low specific speed is indicated. It appears that an attempt to reach impulse conditions in radial turbines is difficult, and only a rather small efficiency improvement can be expected. The approach to be taken in adapting a turbine design to low-specific-speed operation is pointed out, and the deterioration of the blade loading pattern due to such a reduction of the specific speed is shown.

Suppression of Cavitation in a Francis Turbine Runner by Application of 3D Inverse Design Method

2002 ◽  
Author(s):  
Hidenobu Okamoto ◽  
Akira Goto
Keyword(s):  
High Efficiency ◽  
Static Pressure ◽  
Design Method ◽  
Three Dimensional ◽  
Inverse Design ◽  
Francis Turbine ◽  
Blade Loading ◽  
Static Pressure Distribution ◽  
Turbine Runner ◽  
Inverse Design Method

This paper describes a new design method of blade geometry for a Francis turbine runner by using a three-dimensional inverse design method and the Computational Fluid Dynamics (CFD) technique. The design objectives are the suppression of cavitation by reducing the area in which static pressure is lower than the vapor pressure while keeping the efficiency high. In the inverse design method, it is possible to optimize the static pressure distribution in the runner by controlling blade loading parameters and/or stacking condition, which is related to a blade lean angle, for the same design specification. A Francis turbine runner was re-designed by the inverse design method for different blade loading and stacking conditions, and the flow fields were evaluated by applying CFD. It was confirmed that the present design method is very practical and effective to control low pressure region and achieve high efficiency for Francis turbine runners.

scholarly journals Three-Dimensional Inverse Design Method for Hydraulic Machinery

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3210
Author(s):  
Wei Yang ◽  
Benqing Liu ◽  
Ruofu Xiao
Keyword(s):  
High Performance ◽  
Design Method ◽  
Three Dimensional ◽  
Inverse Design ◽  
Blade Loading ◽  
Hydraulic Machinery ◽  
Main Challenge ◽  
Blade Shape ◽  
Stacking Condition ◽  
Inverse Design Method

Hydraulic machinery with high performance is of great significance for energy saving. Its design is a very challenging job for designers, and the inverse design method is a competitive way to do the job. The three-dimensional inverse design method and its applications to hydraulic machinery are herein reviewed. The flow is calculated based on potential flow theory, and the blade shape is calculated based on flow-tangency condition according to the calculated flow velocity. We also explain flow control theory by suppression of secondary flow and cavitation based on careful tailoring of the blade loading distribution and stacking condition in the inverse design of hydraulic machinery. Suggestions about the main challenge and future prospective of the inverse design method are given.

Multi-Objective Optimization of a High Specific Speed Centrifugal Volute Pump Using Three-Dimensional Inverse Design Coupled With Computational Fluid Dynamics Simulations

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Luying Zhang ◽  
Gabriel Davila ◽  
Mehrdad Zangeneh
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Design Method ◽  
Three Dimensional ◽  
Inverse Design ◽  
Computational Time ◽  
Specific Speed ◽  
Meridional Shape ◽  
Inverse Design Method ◽  
Blade Geometry

Abstract This paper presents three different multiobjective optimization strategies for a high specific speed centrifugal volute pump design. The objectives of the optimization consist of maximizing the efficiency and minimizing the cavitation while maintaining the Euler head. The first two optimization strategies use a three-dimensional (3D) inverse design method to parametrize the blade geometry. Both meridional shape and 3D blade geometry are changed during the optimization. In the first approach, design of experiment (DOE) method is used and the pump efficiency is obtained from computational fluid dynamics (CFD) simulations, while cavitation is evaluated by using minimum pressure on blade surface predicted by 3D inverse design method. The design matrix is then used to create a surrogate model where optimization is run to find the best tradeoff between cavitation and efficiency. This optimized geometry is manufactured and tested and is found to be 3.9% more efficient than the baseline with reduced cavitation at high flow. In the second approach, only the 3D inverse design method output is used to compute the efficiency and cavitation parameters and this leads to considerable reduction to the computational time. The resulting optimized geometry is found to be similar to the computationally more expensive solution based on 3D CFD results. In order to compare the inverse design based optimization to the conventional optimization, an equivalent optimization is carried out by parametrizing the blade angle and meridional shape.

Bowl-Type Diffusers for Low Specific-Speed Pumps: An Industrial Application

2006 ◽  
Author(s):  
Paolo Boncinelli ◽  
Roberto Biagi ◽  
Antonio Focacci ◽  
Umberto Corradini ◽  
Andrea Arnone ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Cfd Analysis ◽  
Aerodynamic Design ◽  
Three Dimensional Flow ◽  
Aerodynamic Efficiency ◽  
Recovery Capacity ◽  
Critical Problems ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Numerical Solver

In this paper, the aerodynamic design of a bowl–type diffuser for a low specific–speed pump is presented and described in detail. The main goal was to achieve an optimal configuration in terms of diffuser recovery capacity and stage aerodynamic efficiency, while satisfying severe constraints concerning stage size and multistage feasibility. Both geometrical parametrization tools and a fully–viscous three–dimensional numerical solver were exploited in the design process. The geometrical parameterization allowed one to control and modify the geometry of the component by changing a limited number of parameters. CFD analysis was exploited to assess the effectiveness of the geometrical modifications on the performance, and to identify critical problems. A number of aerodynamic ID coefficients with simple physical meanings were also introduced and used as a support to the design to synthesize the main feature of the strongly three–dimensional flow evolving in the component. As a result, a new stage configuration was developed according to the imposed constraints, whose performance is at the same level as standard pumps of the same class.

Hydrodynamic Design of the Volute of a Centrifugal Pump Using CFD

2011 ◽  
Author(s):  
Rouhollah Torabi ◽  
S. Ahmad Nourbakhsh
Keyword(s):  
Viscous Flow ◽  
Centrifugal Pump ◽  
Static Pressure ◽  
Design Method ◽  
Radial Force ◽  
Inverse Design ◽  
Radial Forces ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Inverse Design Method

The objective of this paper is to develop the shape of an existing volute so that the radial forces in off-design condition become minimum. For this purpose 3-D inverse design method based on the 3-D viscous flow calculations was applied to re-design the geometry of the volute of a low specific speed pump. Various aspects of the geometry change independently to achieve the best one which produces less radial force in off design conditions. Measurements included time-averaged values of velocity and static pressure at a large number of locations in the volute.

Multiobjective Optimization Design of a Pump–Turbine Impeller Based on an Inverse Design Using a Combination Optimization Strategy

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Wei Yang ◽  
Ruofu Xiao
Keyword(s):  
Response Surface ◽  
Optimization Design ◽  
Design Method ◽  
Inverse Design ◽  
Design Parameters ◽  
Surface Model ◽  
Optimization Strategy ◽  
Pump Turbine ◽  
Combination Optimization ◽  
Final Design

This paper presents an automatic multiobjective hydrodynamic optimization strategy for pump–turbine impellers. In the strategy, the blade shape is parameterized based on the blade loading distribution using an inverse design method. An efficient response surface model relating the design parameters and the objective functions is obtained. Then, a multiobjective evolutionary algorithm is applied to the response surface functions to find a Pareto front for the final trade-off selection. The optimization strategy was used to redesign a scaled pump–turbine. Model tests were conducted to validate the final design and confirm the validity of the design strategy.

Performance Evaluation of Centrifugal Compressor Impellers Using Three-Dimensional Viscous Flow Calculations

1984 ◽  
Vol 106 (2) ◽  
pp. 475-481 ◽  
Author(s):  
J. Moore ◽  
J. G. Moore ◽  
P. H. Timmis
Keyword(s):  
Viscous Flow ◽  
Centrifugal Compressor ◽  
Strong Influence ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Tip Leakage Flow ◽  
Compression Process ◽  
Tip Leakage ◽  
Low Specific Speed ◽  
Specific Speed

Calculations of three-dimensional viscous flow in the impeller of a centrifugal compressor are used as the basis of a study of the thermodynamics of the compression process. Flow in a high hub-tip ratio low specific speed impeller of approximately 3.4:1 pressure ratio is considered. Results are presented showing the work and loss production processes in the impeller. A strong influence of tip-leakage flow on the performance of this unshrouded wheel is found.

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