Non-Dimensional Parameters for Comparing Conventional and Counter-Rotating Turbomachines

2019 ◽  
Author(s):  
J. J. Waldren ◽  
C. J. Clark ◽  
S. D. Grimshaw ◽  
G. Pullan
Keyword(s):  
High Efficiency ◽  
Three Dimensional ◽  
Relative Performance ◽  
Design Parameters ◽  
Blade Design ◽  
Finite Radius ◽  
Counter Rotation ◽  
Dimensional Parameters ◽  
Conventional Machine ◽  
Stage Efficiency

Abstract Counter-rotating turbomachines have the potential to be high efficiency, high power density devices. Comparisons between conventional and counter-rotating turbomachines in the literature make multiple and often contradicting conclusions about their relative performance. By adopting appropriate non-dimensional parameters, based on relative blade speed, the design space of conventional machines can be extended to include those with counter-rotation. This allows engineers familiar with conventional turbomachinery to transfer their experience to counter-rotating machines. By matching appropriate non-dimensional parameters the loss mechanisms directly affected by counter-rotation can be determined. A series of computational studies are performed to investigate the relative performance of conventional and counter-rotating turbines with the same non-dimensional design parameters. Each study targets a specific loss source, highlighting which phenomena are directly due to counter-rotation and which are solely due to blade design. The studies range from two-dimensional blade sections to three-dimensional finite radius stages. It is shown that, at hub-to-tip ratios approaching unity, with matched non-dimensional design parameters, the stage efficiency and work output are identical for both types of machine. However, a counter-rotating turbine in the study is shown to have an efficiency advantage over a conventional machine of up to 0.35 percentage points for a hub-to-tip ratio of 0.65. This is due to differences in absolute velocity producing different spanwise blade designs.

NON-DIMENSIONAL PARAMETERS FOR COMPARING CONVENTIONAL AND COUNTER-ROTATING TURBOMACHIN

2021 ◽  
pp. 1-12
Author(s):  
Jonathan Waldren ◽  
Christopher J Clark ◽  
Sam D. Grimshaw ◽  
Graham Pullan
Keyword(s):  
High Efficiency ◽  
Relative Performance ◽  
Design Parameters ◽  
Blade Design ◽  
Finite Radius ◽  
Percentage Points ◽  
Counter Rotation ◽  
Dimensional Parameters ◽  
Conventional Machine ◽  
Stage Efficiency

Abstract Counter-rotating turbomachines have the potential to be high efficiency, high power density devices. Comparisons between conventional and counter-rotating turbomachines in the literature make multiple and often contradicting conclusions about their relative performance. By adopting appropriate non-dimensional parameters, based on relative blade speed, the design space of conventional machines can be extended to include those with counter-rotation. This allows engineers familiar with conventional turbomachinery to transfer their experience to counter-rotating machines. By matching appropriate non-dimensional parameters the loss mechanisms directly affected by counter-rotation can be determined. A series of computational studies are performed to investigate the relative performance of conventional and counter-rotating turbines with the same non-dimensional design parameters. Each study targets a specific loss source, highlighting which phenomena are directly due to counter-rotation and which are solely due to blade design. The studies range from two-dimensional blade sections to threedimensional finite radius stages. It is shown that, at hub-to-tip ratios approaching unity, with matched non-dimensional design parameters, the stage efficiency and work output are identical for both types of machine. However, a counter-rotating turbine in the study is shown to have an efficiency advantage over a conventional machine of up to 0:35 percentage points for a hub-to-tip ratio of 0:65. This is due to differences in absolute velocity producing different spanwise blade designs.

Accelerated 3D Aerodynamic Optimization of Gas Turbine Blades

2014 ◽  
Author(s):  
Philipp Amtsfeld ◽  
Michael Lockan ◽  
Dieter Bestle ◽  
Marcus Meyer
Keyword(s):  
Turbine Blades ◽  
Three Dimensional ◽  
Optimization Process ◽  
Design Parameters ◽  
Blade Design ◽  
Aerodynamic Optimization ◽  
Multi Stage ◽  
Design Variables ◽  
Real Flow ◽  
Blade Model

State-of-the-art aerodynamic blade design processes mainly consist of two phases: optimal design of 2D blade sections and then stacking them optimally along a three-dimensional stacking line. Such a quasi-3D approach, however, misses the potential of finding optimal blade designs especially in the presence of strong 3D flow effects. Therefore, in this paper a blade optimization process is demonstrated which uses an integral 3D blade model and 3D CFD analysis to account for three-dimensional flow features. Special emphasis is put on shortening design iterations and reducing design costs in order to obtain a rapid automatic optimization process for fully 3D aerodynamic turbine blade design which can be applied in an early design phase already. The three-dimensional parametric blade model is determined by up to 80 design variables. At first, the most important design parameters are chosen based on a non-linear sensitivity analysis. The objective of the subsequent optimization process is to maximize isentropic efficiency while fulfilling a minimal set of constraints. The CFD model contains both important geometric features like tip gaps and fillets, and cooling and leakage flows to sufficiently represent real flow conditions. Two acceleration strategies are used to cut down the turn-around time from weeks to days. Firstly, the aerodynamic multi-stage design evaluation is significantly accelerated with a GPU-based RANS solver running on a multi-GPU workstation. Secondly, a response surface method is used to reduce the number of expensive function evaluations during the optimization process. The feasibility is demonstrated by an application to a blade which is a part of a research rig similar to the high pressure turbine of a small civil jet engine. The proposed approach enables an automatic aerodynamic design of this 3D blade on a single workstation within few days.

An Optimum Aero-Design Process of Turbine Blades

2002 ◽  
Author(s):  
C. Xu ◽  
R. S. Amano
Keyword(s):  
Design Process ◽  
High Efficiency ◽  
Pressure Ratio ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Optimization Procedure ◽  
Compressor Blade ◽  
Advanced Technology ◽  
Test Case ◽  
Blade Design

With the development of the advanced technology, the combustion temperature is raised for increased efficiencies. At the same time, the turbine and compressor pressure ratio and the mass flow rate rise; thus causing turbine and compressor blades turning and blade lengths increase. Moreover, the high efficiency requirements had made the turbine and compressor blade design difficult. A turbine airfoil has been custom designed for many years, but an optimization for the section design in a three-dimensional consideration is still a challenge. For a compressor blade design, standard section cannot meet the modern compressor requirements. Modern compressor design has not only needs a custom designed section according to flow situation, but also needs three-dimensional optimizations. Therefore, a good blade design process is critical to the turbines and compressors. A blade design of the turbomachines is one of the important steps for a good turbomachine design. A blade design process not only directly influences the overall machine efficiency but also dramatically impact the design time and cost. In this study, a blade design and optimization procedure was proposed for both turbine and compressor blade design. A compressor blade design was used as a test case. It was shown that the current design process had more advantages than conventional design methodology.

Optimization of the intake port shape for a five-valve gasoline engine

2001 ◽  
Vol 215 (6) ◽  
pp. 739-746 ◽  
Author(s):  
K Lee ◽  
C Lee ◽  
Y Joo
Keyword(s):  
High Efficiency ◽  
Gasoline Engine ◽  
Three Dimensional ◽  
Design Guidelines ◽  
Design Parameters ◽  
Computer Assisted ◽  
Intake Port ◽  
Port Design ◽  
Visualization Experiments ◽  
Valve Engine

For the development of a high efficiency gasoline engine, the optimization of the intake port shape for a five-valve engine has been studied. Intake multivalve cylinder heads were manufactured by using a three-dimensional computer-assisted design program, and steady state flow experiments and flow visualization experiments have been performed with these cylinder heads. The five-valve engines, which have larger valve opening areas, have larger intake flowrates and higher tumble ratios than the four-valve engines. The effects of intake port design parameters of a five-valve engine on the intake flowrate and tumble were studied, and the design guidelines for the five-valve engines were established.

A numerical study on the effects of design parameters on the acoustics noise of a high efficiency propeller

2018 ◽  
Vol 91 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Yunpeng Ma ◽  
Na Guo
Keyword(s):  
Noise Reduction ◽  
High Efficiency ◽  
Numerical Study ◽  
Three Dimensional ◽  
Aerodynamic Noise ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Content Type ◽  
Simulation Based ◽  
S Model

PurposeA numerical study on the aerodynamic noise generation of a high efficiency propeller is carried out.Design/methodology/approachThree-dimensional numerical simulation based on Reynolds averaged N-S model is performed to obtain the aerodynamic performance of the propeller. Then, the result of the aerodynamic analysis is given as input of the acoustic calculation. The sound is calculated using the Farassat 1A which was derived from Ffowcs Williams–Hawkings equation and is compared with the measurements.FindingsMoreover, the fan is modified for noise reduction by changing its geometrical parameters such as span, chord length and torsion angle.Originality/valueThe variation trend of aerodynamic and acoustic are compared and discussed for different modification tasks. Some meaningful conclusions are drawn on the noise reduction of propeller.

Two- and Three-Dimensional Prescribed Surface Curvature Distribution Blade Design (CIRCLE) Method for the Design of High Efficiency Turbines, Compressors, and Isolated Airfoils

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
T. Korakianitis ◽  
M. A. Rezaienia ◽  
I. A. Hamakhan ◽  
A. P. S. Wheeler
Keyword(s):  
Turbine Blade ◽  
High Efficiency ◽  
Turbine Blades ◽  
Circle Method ◽  
Three Dimensional ◽  
Leading Edge ◽  
Surface Curvature ◽  
Blade Design ◽  
Compressor Blades ◽  
Curvature Distribution

The prescribed surface curvature distribution blade design (CIRCLE) method is presented for the design of two-dimensional (2D) and three-dimensional (3D) blades for axial compressors and turbines, and isolated blades or airfoils. The original axial turbine blade design method is improved, allowing it to use any leading-edge (LE) and trailing-edge (TE) shapes, such as circles and ellipses. The method to connect these LE and TE shapes to the remaining blade surfaces with curvature and slope of curvature continuity everywhere along the streamwise blade length, while concurrently overcoming the “wiggle” problems of higher-order polynomials is presented. This allows smooth surface pressure distributions, and easy integration of the CIRCLE method in heuristic blade-optimization methods. The method is further extended to 2D and 3D compressor blades and isolated airfoil geometries providing smooth variation of key blade parameters such as inlet and outlet flow angles, stagger angle, throat diameter, LE and TE radii, etc. from hub to tip. One sample 3D turbine blade geometry is presented. The efficacy of the method is examined by redesigning select blade geometries and numerically evaluating pressure-loss reduction at design and off-design conditions from the original blades: two typical 2D turbine blades; two typical 2D compressor blades; and one typical 2D isolated airfoil blade geometries are redesigned and evaluated with this method. Further extension of the method for centrifugal or mixed-flow impeller geometries is a coordinate transformation. It is concluded that the CIRCLE method is a robust tool for the design of high-efficiency turbomachinery blades.

A Turbomachinery Blade Design and Optimization Procedure

2002 ◽  
Author(s):  
C. Xu ◽  
R. S. Amano
Keyword(s):  
Design Process ◽  
High Efficiency ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Optimization Procedure ◽  
Compressor Blade ◽  
Advanced Technology ◽  
Test Case ◽  
Blade Design ◽  
Design And Optimization

With the development of the advanced technology, the combustion temperature is raised for increased efficiencies. At the same time, the turbine and compressor pressure ratio and the mass flow rate rise; thus causing turbine and compressor blades turning and blade lengths increase. Moreover, the high efficiency requirements had made the turbine and compressor blade design difficult. A turbine airfoil has been custom designed for many years, but an optimization for the section design in a three-dimensional consideration is still a challenge. For a compressor blade design, standard section cannot meet the modern compressor requirements. Modern compressor design has not only needs a custom designed section according to flow situation, but also needs three-dimensional optimizations. Therefore, a good blade design process is critical to the turbines and compressors. A blade design of the turbomachines is one of the important steps for a good turbomachine design. A blade design process not only directly influences the overall machine efficiency but also dramatically impact the design time and cost. In this study, a blade design and optimization procedure was proposed for both turbine and compressor blade design. A compressor blade design was used as a test case. It was shown that the current design process had more advantages than conventional design methodology.

Two- and Three-Dimensional Prescribed Surface Curvature Distribution Blade Design (CIRCLE) Method for the Design of High Efficiency Turbines, Compressors, and Isolated Airfoils

2011 ◽  
Author(s):  
T. Korakianitis ◽  
I. A. Hamakhan ◽  
M. A. Rezaienia ◽  
A. P. S. Wheeler
Keyword(s):  
Turbine Blade ◽  
High Efficiency ◽  
Turbine Blades ◽  
Circle Method ◽  
Three Dimensional ◽  
Leading Edge ◽  
Surface Curvature ◽  
Blade Design ◽  
Compressor Blades ◽  
Curvature Distribution

The prescribed surface curvature distribution blade design (CIRCLE) method is presented for the design of two-dimensional (2D) and three-dimensional (3D) blades for axial compressors and turbines, and isolated blades or airfoils. The original axial turbine blade design method is improved, allowing it to use any leading-edge (LE) and trailing-edge (TE) shapes, such as circles and ellipses. The method to connect these LE and TE shapes to the remaining blade surfaces with curvature and slope of curvature continuity everywhere along the streamwise blade length, while concurrently overcoming the “wiggle” problems of higher-order polynomials is presented. This allows smooth surface pressure distributions, and easy integration of the CIRCLE method in heuristic blade-optimization methods. The method is further extended to 2D and 3D compressor blades and isolated airfoil geometries providing smooth variation of key blade parameters such as inlet and outlet flow angles, stagger angle, throat diameter, LE and TE radii etc. from hub to tip. One sample 3D turbine blade geometry is presented. The efficacy of the method is examined by redesigning select blade geometries and numerically evaluating pressure-loss reduction at design and off-design conditions from the original blades: two typical 2D turbine blades; two typical 2D compressor blades; and one typical 2D isolated airfoil blade geometries are redesigned and evaluated with this method. Further extension of the method for centrifugal or mixed-flow impeller geometries is a coordinate transformation. It is concluded that the CIRCLE method is a robust tool for the design of high-efficiency turbomachinery blades.

Development of 3D Parameterized Design System for Turbine Compressor Impellers

2006 ◽  
Vol 532-533 ◽  
pp. 737-740
Author(s):  
Hang Gao ◽  
Jia Peng Yu ◽  
Xue Shu Liu
Keyword(s):  
Programming Language ◽  
High Efficiency ◽  
Three Dimensional ◽  
3D Models ◽  
Database Management System ◽  
Sql Server ◽  
Design Parameters ◽  
Design System ◽  
Parameterized Design ◽  
Engineering Drawings

Aiming at the characteristics of turbine compressor’s impellers, such as complexity in surface, assembled structure and variety in parameter, the step-by-step design thought is put forward, which realizes the high efficiency and visualization of parameterized design through distributing design parameters evenly to several phases or interfaces. According to the demand of the enterprise, SolidWorks CAD Software was chosen as the three-dimensional CAD platform, SQL Server 7.0 was chosen as the database management system, and Visual C++ was chosen for the programming language of secondary developing. Then the parameterized design system for series turbine compressor impellers is developed, which realizes automatic creation of 3D models and 2D engineering drawings using template technique.

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