Arbitrary Blade Section Design Based on Viscous Considerations. Background Information

1996 ◽  
Vol 118 (2) ◽  
pp. 358-363 ◽  
Author(s):  
B. Bouras ◽  
F. Karagiannis ◽  
G. Leoutsakos ◽  
K. C. Giannakoglou ◽  
K. D. Papailiou
Keyword(s):  
Viscous Flow ◽  
Design Method ◽  
Design Procedure ◽  
Optimization Procedure ◽  
Shear Layers ◽  
Background Information ◽  
Joint Paper ◽  
Blade Optimization ◽  
Section Design ◽  
Blade Section

Background information is presented on an arbitrary blade section design method which is outlined in a joint paper. This information concerns the assumptions, the development, and the predictive capabilities of the viscous flow calculation tool used in the design procedure. General properties of laminar and turbulent, unseparated or separated compressible shear layers, necessary for the blade optimization procedure, are discussed.

Arbitrary Blade Section Design Based on Viscous Considerations. Blade Optimization

1996 ◽  
Vol 118 (2) ◽  
pp. 364-369
Author(s):  
B. Bouras ◽  
F. Karagiannis ◽  
P. Chaviaropoulos ◽  
K. D. Papailiou
Keyword(s):  
Optimization Design ◽  
Design Procedure ◽  
Optimization Procedure ◽  
Shear Layers ◽  
Turbulent Shear ◽  
Design And Optimization ◽  
Blade Optimization ◽  
Blade Shape ◽  
Section Design ◽  
Blade Section

A blade design and optimization procedure is presented in this work, which is based on viscous flow considerations. This procedure concerns the design of optimum rotating arbitrary compressible high subsonic compressor and turbine blade shapes. It takes into account the effects of wall curvature and Coriolis force on turbulence, while it allows the variation of stream surface radius, along which the blade shape is placed, as well as streamtube width, with meridional distance. In order to establish the inverse part of the viscous optimization procedure, aspects such as laminar stability, transition, optimum deceleration and, more generally, the behaviour of compressible attached and separated shear layers are discussed. A plane on which all the general properties of the compressible laminar and turbulent shear layers appear, is constructed and the generation of optimum shear layers for the critical side of the blade shape is established. The complete optimization (design) procedure is then described and discussed, while various designs realized by the present procedure are presented at the end of this paper.

Refinement of the Mean Streamline Method of Blade Section Design

1977 ◽  
Vol 99 (3) ◽  
pp. 561-566 ◽  
Author(s):  
M. W. McBride
Keyword(s):  
Design Method ◽  
Lift Coefficient ◽  
Recent Effort ◽  
Mean Flow ◽  
Surface Pressure Distribution ◽  
Section Design ◽  
Blade Section ◽  
The Mean ◽  
Design Characteristics ◽  
Streamline Method

The Mean Streamline Method of cascade blade section design developed by Wislicenus correlates the differences in the shape of the blade camber-line and the one-dimensional mean flow streamline. Recent effort has been directed toward the extension of this design method, to cover a wider range of loading distributions, including trailing edge loaded blades, and blades with higher than usual solidities (C/S). A computer analysis of many available blade shapes for subsonic compressors and pumps with differing loading distributions that have been tested experimentally was made. Relations between the deviation of the camber-line from the mean flow streamline as a function of the lift coefficient, solidity, a loading distribution parameter and blade stagger angle were found. Using these correlations, a computerized design method was developed which rapidly produces blade shapes with specified design characteristics. A radial equilibrium theory is utilized to compute the actual blade surface pressure distribution. When a blade is to be designed which is similar to existing designs, the method has proven very reliable.

Design of Turbine Blades Suitable for Supersonic Relative Inlet Velocities and the Investigation of Their Performance in Cascades: Part I-Theory and Design

1966 ◽  
Vol 8 (1) ◽  
pp. 110-128 ◽  
Author(s):  
C. D. Colclough
Keyword(s):  
Mach Number ◽  
Vortex Flow ◽  
Design Method ◽  
Turbine Blades ◽  
Design Procedure ◽  
Uniform Flow ◽  
Turning Angle ◽  
Contraction Ratio ◽  
Trailing Edges ◽  
Blade Section

Certain applications for turbines require units with a large work output per stage. The whole of the expansion takes place across the nozzles and at inlet to the turbine blades the gas velocity is supersonic. Impulse blading is usually employed with flow turning angles ranging from 90° to 160°. However, advancing steam conditions suggest that the first stages of turbines presently designed with subsonic blading may have to accept increasing heat drops to reduce the steam temperature to the first moving row and to reduce gland losses. Under these conditions blading designed to accept supersonic velocities could be employed. This paper, which deals with blading designed specifically for supersonic flow, is divided into two parts, the first of which outlines the theory and design of the blading. The second part describes tests run on cascades of these blades and discusses the results. In Part I a design method based on inviscid isentropic supersonic vortex flow theory is evolved in which the uniform flow ahead of the blade is transformed into a vortex flow, turned through the required angle and then converted back to uniform flow again at the exit. The blades thus obtained are cusped and a design method has been developed to produce blades with finite leading and trailing edges. Blades designed on this basis were tested in cascade and the results were used to modify the design procedure. The revised design method for non-isentropic conditions incorporating the measured losses and allowable contraction ratio was programmed for a Ferranti Pegasus digital computer and this was used to produce an impulse blade section with a flow turning angle of approximately 137° and capable of accepting an upstream Mach number of 1.285 and a blade inlet Mach number of 1.514.

Simultaneous Optimization of Impeller Blade Loading Distribution and Meridional Geometry for Aerodynamic Design of Centrifugal Compressor

2019 ◽  
Author(s):  
Kaito Manabe ◽  
Sasuga Ito ◽  
Masato Furukawa ◽  
Kazutoyo Yamada ◽  
Nobuhito Oka ◽  
...  
Keyword(s):  
Viscous Flow ◽  
Design Method ◽  
Flow Analysis ◽  
Design Procedure ◽  
Simultaneous Optimization ◽  
Low Flow ◽  
Aerodynamic Design ◽  
Impeller Blade ◽  
Rate Condition ◽  
Blade Loading

Abstract The present optimum design method has been advanced for simultaneous optimization of impeller blade loading distribution and meridional geometry. This is based on an aerodynamic design method and a genetic algorithm. The aerodynamic design method consists of two parts: a meridional viscous flow analysis and a two-dimensional inverse blade design procedure. In the meridional viscous flow analysis, an axisymmetric viscous flow is numerically analyzed on a two-dimensional grid to determine the flow distribution around the impeller and diffuser. Effects of blades onto the axisymmetric flow field are considered by a blade force modeling. In the inverse blade design procedure, 3-D impeller geometry can be obtained from the result of meridional viscous flow analysis and the predetermined blade loading distribution. In the optimization procedure, the total pressure ratio and adiabatic efficiency obtained from the meridional viscous flow analysis are employed as objective functions. As a constraint of the optimization, mass flux distribution at the impeller trailing edge is introduced in the evaluation procedure, in order to suppress the boundary layer development near the shroud, especially under low flow rate condition. Total performances and three-dimensional flow fields of centrifugal compressors have been analyzed by 3D-RANS simulations to certify effectiveness of the present design method. The 3D-RANS simulations and the flow visualization have been applied to a conventional centrifugal compressor and optimized design cases. From the analysis results, the performance enhancement of optimized designs is confirmed under low flow rate condition including design point. In addition to that, it is revealed that the constraint works effectively on the performance improvement. As a result, construction of the simultaneous optimization using the aerodynamic design method and the genetic algorithm is successfully achieved.

Integrated Design on Structural Shape and Controller of Spin Stand for High-Speed Positioning

2005 ◽  
Author(s):  
H. Ando ◽  
T. Sakai ◽  
G. Obinata
Keyword(s):  
High Speed ◽  
Design Method ◽  
Integrated Design ◽  
Design Procedure ◽  
Optimization Procedure ◽  
Shape Design ◽  
Performance Indices ◽  
Closed Loop System ◽  
Structural Shape ◽  
Iterative Design

This paper discusses the integrated design on structural shape and controller of positioning actuators for spin stands. To allow highly flexible shape design of the mechanism for the positioning actuator and to improve the calculation efficiency in the shape optimization, this paper proposes an integrated design method in which a structural shape is defined like as a skeleton and meats and a genetic algorithm (GA) is used to search the combination of the skeleton and meats for obtaining better performance of the closed-loop system in iterative design procedure. The iterative optimization procedure includes the shape and the controller updates. It is shown in design examples that the proposed integrated design method can improve the performance of the positioning actuator according to the performance indices. Therefore, the proposed method is effective to such active mechanisms that harder specifications are assigned to the design.

scholarly journals A Two-Round Optimization Design Method for Aerostatic Spindles Considering the Fluid–Structure Interaction Effect

2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang
Keyword(s):  
Optimal Design ◽  
Optimization Design ◽  
Design Method ◽  
Fluid Structure Interaction ◽  
Design Procedure ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerostatic Spindle

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.

AN INDEPENDENT ACTIVE BALANCER FOR PLANAR MECHANISMS

2007 ◽  
Vol 31 (2) ◽  
pp. 167-190 ◽  
Author(s):  
Zhang Ying ◽  
Yao Yan-An ◽  
Cha Jian-Zhong
Keyword(s):  
Working Conditions ◽  
Design Method ◽  
Design Procedure ◽  
Vibration Absorber ◽  
Planar Mechanisms ◽  
Dynamic Balancing ◽  
Joint Coupling ◽  
Design Requirements ◽  
Novel Concept ◽  
Two Degree Of Freedom

This paper proposed a novel concept of active balancer for dynamic balancing of planar mechanisms. Somewhat similar to a vibration absorber, the active balancer is designed as an independent device, which is placed outside of the mechanism to be balanced and can be installed easily. It consists of a two degree-of-freedom (DOF) linkage with two input shafts, one of which is connected to the output shaft of the mechanism to be balanced by a joint coupling, and the other one is driven by a controllable motor. Flexible dynamic balancing adapted to different working conditions can be achieved by varying speed trajectories of the control motor actively. A design method is developed for selecting suitable speed trajectories and link parameters of the two DOF linkage of the balancer to meet various design requirements and constraints. Numerical examples are given to demonstrate the design procedure and to verify the feasibility of the proposed concept.

scholarly journals Novel Robust Design Method of Multilayer Optical Coatings

ISRN Optics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Suyong Wu ◽  
Xingwu Long ◽  
Kaiyong Yang
Keyword(s):  
Robust Design ◽  
Optimization Design ◽  
Design Method ◽  
Analytical Calculation ◽  
Design Procedure ◽  
Deposition Process ◽  
Practical Significance ◽  
Optical Coatings ◽  
Optical Films ◽  
Robust Design Method

We present a novel fast robust design method of multilayer optical coatings. The sensitivity of optical films to production errors is controlled in the whole optimization design procedure. We derive an analytical calculation model for fast robust design of multilayer optical coatings. We demonstrate its effectiveness by successful application of the robust design method to a neutral beam splitter. It is showed that the novel robust design method owns an inherent fast computation characteristic and the designed film is insensitive to the monitoring thickness errors in deposition process. This method is especially of practical significance to improve the mass production yields and repetitive production of high-quality optical coatings.

A Framework for Component Layout and Geometry Design of Mechanical Systems: Configuration Network and its Viewing Control

1995 ◽  
Author(s):  
Kikuo Fujita ◽  
Shinsuke Akagi
Keyword(s):  
Design Method ◽  
Mechanical Systems ◽  
Optimization Procedure ◽  
Computational Design ◽  
Object Oriented Programming ◽  
Design System ◽  
Air Conditioner ◽  
Programming Technique ◽  
Geometry Design ◽  
Component Layout

Abstract A Framework of computational design method and model is proposed for layout and geometry design of complicated mechanical systems, which is named “configuration network and its viewing control”. In the method, a design object is represented with a set of declarative relationships among various elements of a system, that is, configurations, which is gradually extended from schematic structure to exact layout and geometry through design process. Since a whole of such configurations forms a too complicated network to compute all together, how to view subparts is controlled based on levels of granularity and width of scope range. Such a configuration network is made to grow and refined through embodying geometry and layout corresponding to a focused subpart with a numerical optimization procedure. The framework has also an ability to flexibly integrate with engineering analysis. Moreover, a design system is implemented with an object-oriented programming technique, and it is applied to a design problem of air conditioner units in order to show the validity and effectiveness of the framework.

Sign in / Sign up

Export Citation Format

Share Document