Aerodynamic Design for Wind-Lens Turbine Using Optimization Technique

Author(s):  
Nobuhito Oka ◽  
Masato Furukawa ◽  
Kazutoyo Yamada ◽  
Kota Kido

An optimum aerodynamic design method has been developed for the new type of wind turbine called “wind-lens turbine”. The wind-lens turbine has a diffuser with brim called “wind-lens”, by which the wind concentration on the turbine rotor and the significant enhancement of the turbine output can be achieved. The present design method is based on a genetic algorithm (GA) and a quasi-three-dimensional design of turbine rotor. The quasi-three-dimensional design consists of two parts: meridional viscous flow calculation and two-dimensional blade element design. In the meridional viscous flow calculation, an axisymmetric viscous flow is numerically analyzed on a meridional plane to determine the wind flow rate through the wind-lens and the spanwise distribution of the rotor inlet flow. In the two-dimensional rotor blade element design, the turbine rotor blade profile is determined by a one-dimensional through flow modeling for the wind-lens turbine and a two-dimensional blade element theory based on the momentum theorem of the ducted turbine. In the present optimization method, the Non-dominated Sorting Genetic Algorithm II (NSGA-II) is used as evaluation and selection model. The Real-coded Ensemble Crossover (REX) is used as crossover model. The present aerodynamic design method has been applied to the coupled design of turbine rotor and wind-lens. Total performances and flow fields of the wind-lens turbines designed have been investigated by Reynolds averaged Navier-Stokes simulations, in order to verify the present design method.

Author(s):  
Nobuhito Oka ◽  
Masato Furukawa ◽  
Kazutoyo Yamada ◽  
Kenta Kawamitsu ◽  
Kota Kido ◽  
...  

An optimum aerodynamic design method for the new type of wind turbine called “wind-lens turbine” has been developed. The wind-lens turbine has a diffuser with brim called “wind-lens”, by which the wind concentration on the turbine rotor and the significant enhancement of the turbine output can be achieved. In order to design efficient wind-lens turbines, an aerodynamic design method for the simultaneous optimization of rotor blade and wind-lens has been developed. The present optimum design method is based on a genetic algorithm (GA) and a quasi-three-dimensional design of turbine rotor. In the GA procedure, the Non-dominated Sorting Genetic Algorithm II (NSGA-II) is used as evaluation and selection model. The Real-coded Ensemble Crossover (REX) is used as crossover model. The quasi-three-dimensional design consists of two parts: meridional viscous flow calculation and two-dimensional blade element design. In the meridional viscous flow calculation, an axisymmetric viscous flow is numerically analyzed on a meridional plane to determine the wind flow rate through the wind-lens and the spanwise distribution of the rotor inlet flow. In the two-dimensional rotor blade element design, the turbine rotor blade profile is determined by a one-dimensional through flow modeling for the wind-lens turbine and a two-dimensional blade element theory based on the momentum theorem of the ducted turbine. Total performances and three-dimensional flow fields of the optimized wind-lens turbines have been investigated by Reynolds averaged Navier-Stokes (RANS) simulations, in order to verify the present design method. The RANS simulations and the flow visualization have been applied to conventional and optimum design cases of the wind-lens turbine, in order to elucidate the relation between their aerodynamic performances and the flow fields around them. The numerical results show that separation vortices behind the wind-lens brim play a major role in the wind concentration and the diffuser performance of the wind-lens. As a result, it is found that the aerodynamic performance of wind-lens turbine is significantly affected by the interrelationship between the internal and external flow fields around the wind-lens.


Author(s):  
H Chen

This paper discusses aerodynamic design methods of volute casings used in turbocharger turbines. A quasi-three-dimensional (Q-3D) design method is proposed in which a group of extended two-dimensional potential flow equations and the streamline equation are numerically solved to obtain the geometry of spiral volutes. A tongue loss model, based on the turbulence wake theory, is also presented, and good agreement with experimental data is shown.


Author(s):  
Nobuhito Oka ◽  
Masato Furukawa ◽  
Kazutoyo Yamada ◽  
Sasuga Itou ◽  
Seiichi Ibaraki ◽  
...  

An optimum aerodynamic design method for centrifugal compressor impeller has been developed. The present optimum design method is using a genetic algorithm (GA) and a two-dimensional inverse blade design method based on a meridional viscous flow analysis. In the meridional viscous flow analysis, an axisymmetric viscous flow is numerically analyzed on a two-dimensional meridional grid to determine the flow distribution around the impeller. Full and splitter blade effects to the flow field are successfully evaluated in the meridional viscous flow analysis by a blade force modeling. In the inverse blade design procedure, blade loading distribution is given as the design variable. In the optimization procedure, the total pressure rise and adiabatic efficiency obtained from the meridional viscous flow analysis are employed as objective functions. Aerodynamic performance and three-dimensional flow fields in the Pareto-optimum design and conventional design cases have been investigated by three-dimensional Reynolds averaged Navier-Stokes (3D-RANS) and experimental analyses. The analyses results show performance improvements and suppressions of flow separations on the suction surfaces in the optimum design cases. Therefore, the present aerodynamic optimization using the inverse method based on the meridional viscous flow analysis is successfully achieved.


Author(s):  
Sasuga Ito ◽  
Kazutoyo Yamada ◽  
Masato Furukawa ◽  
Kaito Manabe ◽  
Nobuhito Oka ◽  
...  

Higher aerodynamic performance of turbochargers has been demanded because of vehicle engine down-sizing. Centrifugal compressors for automotive turbochargers require higher efficiency and wider operating range. Meridional geometry of the centrifugal compressors is one of their design specifications and it drastically affects the aerodynamic performance of the compressors. In this study, we designed the meridional geometry by using the aerodynamic design method based on a meridional viscous flow analysis and investigated the relation between the meridional geometry and the aerodynamic performance by analyzing meridional viscous flow calculation results and three-dimensional RANS calculation results. As a result, the relation between the boundary layer development near the shroud and the mass flux at the trailing edge was found out according to the meridional viscous flow calculation results. In addition, the relation and the performance improvement were confirmed according to experimental results.


1990 ◽  
Author(s):  
A. Kirschner ◽  
H. Stoff

A cascade design-method is presented which complements the meridional through-flow design procedure of turbomachines. Starting from an axisymmetric flow field and the streamline geometry in the meridional plane this simple method produces a solution for the quasi three-dimensional flow field and the blade-element geometry on corresponding stream surfaces. In addition, it provides intra-blade data on loss and turning required for a consistent design and a convenient means of optimizing blade loading. The purpose of this paper is to describe the theoretical basis of the method and to illustrate its application in the design of transonic compressors.


2003 ◽  
Vol 125 (1) ◽  
pp. 158-165 ◽  
Author(s):  
A. Ashrafizadeh ◽  
G. D. Raithby ◽  
G. D. Stubley

This paper describes a method for calculating the shape of duct that leads to a prescribed pressure distribution on the duct walls. The proposed design method is computationally inexpensive, robust, and a simple extension of existing computational fluid dynamics methods; it permits the duct shape to be directly calculated by including the coordinates that define the shape of the duct wall as dependent variables in the formulation. This “direct design method” is presented by application to two-dimensional ideal flow in ducts. The same method applies to many problems in thermofluids, including the design of boundary shapes for three-dimensional internal and external viscous flows.


1990 ◽  
Vol 112 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Zhao Xiaolu ◽  
Qin Lisen

An aerodynamic design method, which is based on the Mean Stream Surface Method (MSSM), has been developed for designing centrifugal compressor impeller blades. As a component of a CAD system for centrifugal compressor, it is convenient to use the presented method for generating impeller blade geometry, taking care of manufacturing as well as aerodynamic aspects. The design procedure starts with an S2m indirect solution. Afterward from the specified S2m surface, by the use of Taylor series expansion, the blade geometry is generated by straight-line elements to meet the manufacturing requirements. Simultaneously, the fluid dynamic quantities across the blade passage can be determined directly. In terms of these results, the designer can revise the distribution of angular momentum along the shroud and hub, which are associated with blade loading, to get satisfactory velocities along the blade surfaces in order to avoid or delay flow separation.


2016 ◽  
Vol 18 (32) ◽  
pp. 22122-22128 ◽  
Author(s):  
Fernando Buendía ◽  
Jorge A. Vargas ◽  
Marcela R. Beltrán ◽  
Jack B. A. Davis ◽  
Roy L. Johnston

The combined use of a genetic algorithm and Density Functional Theory (DFT) calculations allows us to explore the potential energy surface. Our results show interesting effects on the geometries of the clusters on deposition. Two-dimensional clusters in the gas phase become three-dimensional and vice versa.


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