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.

Optimization of Microturbine Aerodynamics Using CFD, Inverse Design and FEM Structural Analysis: 1st Report — Compressor Design

2004 ◽  
Author(s):  
Kosuke Ashihara ◽  
Akira Goto ◽  
Shijie Guo ◽  
Hidenobu Okamoto
Keyword(s):  
High Speed ◽  
Structural Reliability ◽  
Design Method ◽  
Three Dimensional ◽  
Design Procedure ◽  
Inverse Design ◽  
Blade Profile ◽  
Vaned Diffuser ◽  
Performance Improvements ◽  
Inverse Design Method

In this paper, a new aerodynamic design procedure is presented for a centrifugal compressor stage of a microturbine system. To optimize the three-dimensional (3-D) flows and the performance, an inverse design method, which numerically generates the 3-D blade geometry for specified blade loading distribution, has been applied together with the numerical validation using CFD (Computational Fluid Dynamics) and FEM (Finite Element Method). The blade profile along the shroud surface of the impeller was optimized based on the 3-D inverse design and CFD. However, the blade profile towards the hub surface was modified geometrically to achieve a nearly radial blade element especially at the inducer part of the impeller, in order to meet the required structural strength. The modified impeller successfully kept similar aerodynamic performance as that of a blade with a fully 3-D shape, whilst showing improved structural reliability. So, the proposed method to adopt the blade profile designed by the inverse method along the shroud, and to geometrically modify the blade profile towards the hub, was confirmed to be effective to design a high-speed compressor impeller. The vaned diffuser has also been re-designed using the inverse design method. The corner separation in the conventional wedge-type diffuser channel was suppressed in the new design. The stage performance improvements were confirmed by stage calculations using CFD.

The Calculation of Marine Propellers Based on Lifting-Surface Theory

1961 ◽  
Vol 5 (03) ◽  
pp. 1-14
Author(s):  
Pao C. Pien
Keyword(s):  
High Speed ◽  
Design Method ◽  
Design Procedure ◽  
Rate Of Change ◽  
Numerical Work ◽  
Surface Theory ◽  
Marine Propellers ◽  
Propeller Design ◽  
Lifting Surface ◽  
Blade Area

Since the present theoretical propeller design method is based on the lifting-surface theory formulated by Ginzel and Ludwieg, an improvement to this lifting-surface theory is made first. Aside from the fact that the improved lifting-surface theory is more general with respect to blade outline and the loading distribution over the blade area, the most important improvement is in the method of obtaining the induced mean lines. In the new theory the induced mean line at any radius is derived from the down-wash distribution along the entire chord length rather than from the rate of change of the down wash at the middle chord as has been done by Ginzel and Ludwieg. The results obtained from the new method show that the induced mean line at any radius is not a function of the chordwise loading distribution at that radius alone but a function of the loading distribution over the entire blade area and the blade outline. Based on the improved theory a new theoretical propeller design method has been developed. The numerical work involved in this design method has been programmed into a high-speed computer for a special case of uniform chordwise loading distribution. Two design examples have been carried out in accordance with the new design procedure, one with skewed blade and the other with symmetrical blade. The experimental verification of the work presented here will be done in the near future.

Design of an Actuated Flexible Arm for Improved Vibration Properties

2003 ◽  
Vol 9 (9) ◽  
pp. 1041-1056 ◽  
Author(s):  
M. Moallem ◽  
R. V. Patel ◽  
K. Khorasani
Keyword(s):  
Cost Function ◽  
Dynamic Behavior ◽  
Closed Loop ◽  
Open Loop ◽  
Loop System ◽  
Shape Design ◽  
Closed Loop System ◽  
Structural Shape ◽  
Flexural Mode ◽  
Flexible Arm

In this paper, a multi-objective optimization index is introduced for improving the dynamic behavior of an actuated structurally flexible arm through geometric shape design. The improvement in the dynamic behavior is achieved by defining a vector optimization cost function. This cost function is associated with the frequency of the lowest system zero when joint angles are taken as outputs, the gain sensitivity of open-loop system modes, and the gain sensitivity of the closed-loop system modes at its transmission zeros. Moreover, a general relationship is obtained between the system pole and zero locations. In particular, it is shown that the magnitude of each system zero is smaller than a corresponding flexural mode and thus the smallest zero always occurs before the smallest pole and should therefore be considered in structural shape design. The design method is applied for finding an optimized structural shape for a single-link flexible arm. The optimized link is shown to yield superior robustness and performance characteristics in a closed-loop system when compared to the non-optimized uniform link. Thus, simpler control schemes can be utilized for the optimized flexible-link system compared to the non-optimized case.

Design Optimization of a Rocker-Joint Silent Chain and Sprocket Drive Based on the Mesh Performance Indices

2012 ◽  
Vol 197 ◽  
pp. 104-109 ◽  
Author(s):  
Wen Yi Su ◽  
Yu Ren Wu
Keyword(s):  
Design Optimization ◽  
Design Procedure ◽  
Optimization Procedure ◽  
Design Parameters ◽  
Chain Drive ◽  
Performance Indices ◽  
Tooth Contact Analysis ◽  
Noise Vibration ◽  
Chain Drives ◽  
Novel Design

Improvement on noise, vibration and wear in silent chain drives is always an important research subject. However, design methods revealed in public are few because the silent chain shapes are variable and complex. A feasible design procedure is extremely required for improving transmission performance of chain drives. Therefore, a novel design optimization procedure for the rocker-joint silent (RJS) chain and sprocket drive is proposed in this paper. The mathematical models of geometry generation, tooth contact analysis and impact velocities at different mesh stages and chain raise amount in the RJS chain drive have been established. Besides, impact velocities and raise amount which may produce ill effects in the chine drive are incorporated as a multi-objective function to carry out the global minimization trying to find out the optimal design parameters for RJS chain drives. The single-objective optimization trends have also been verified with the previous references.

Design for a 2-DOF Motion Platform

2011 ◽  
Vol 23 (1) ◽  
pp. 19-33 ◽  
Author(s):  
Ping-Lin Wu ◽  
◽  
Yang-Hung Chang ◽  
Chung-Shu Liao ◽  
Wei-Hua Chieng ◽  
...  
Keyword(s):  
Global Optimization ◽  
Objective Function ◽  
Design Method ◽  
Low Cost ◽  
Dynamic Performance ◽  
Optimization Procedure ◽  
Forward Kinematics ◽  
Performance Indices ◽  
Motion Platform ◽  
Mechanical Advantage

This study investigates the feasibility of adopting the 2-DOF motion platform design to combine optimal workspace and mechanical advantage, which is considered as important for low-cost simulators. A design method to optimize an objective function is presented. This method consolidates some major issues related to workspace volume, workspace symmetry, and actuator power requirements. Performance indices obtained from the inverse/forward kinematics are adopted within a global optimization procedure, GA, to determine the design spread-angle that improves the static and dynamic performance.

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.

Toward the Integrated Design of Organic Rankine Cycle Power Plants: A Method for the Simultaneous Optimization of Working Fluid, Thermodynamic Cycle, and Turbine

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Matthias Lampe ◽  
Carlo De Servi ◽  
Johannes Schilling ◽  
André Bardow ◽  
Piero Colonna
Keyword(s):  
Integrated Design ◽  
Organic Rankine Cycle ◽  
Design Procedure ◽  
Thermodynamic Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Working Fluid ◽  
Small Scale ◽  
Iterative Design ◽  
Selection Of

Abstract The conventional design of organic Rankine cycle (ORC) power systems starts with the selection of the working fluid and the subsequent optimization of the corresponding thermodynamic cycle. More recently, systematic methods have been proposed integrating the selection of the working fluid into the optimization of the thermodynamic cycle. However, in both cases, the turbine is designed subsequently. This procedure can lead to a suboptimal design, especially in the case of mini- and small-scale ORC systems, since the preselected combination of working fluid and operating conditions may lead to infeasible turbine designs. The resulting iterative design procedure may end in conservative solutions after multiple trial-and-error attempts due to the strong interdependence of the many design variables and constraints involved. In this work, we therefore present a new design and optimization method integrating working fluid selection, thermodynamic cycle design, and preliminary turbine design. To this purpose, our recent 1-stage continuous-molecular targeting (CoMT)-computer-aided molecular design (CAMD) method for the integrated design of the ORC process and working fluid is expanded by a turbine meanline design procedure. Thereby, the search space of the optimization is bounded to regions where the design of the turbine is feasible. The resulting method has been tested for the design of a small-scale high-temperature ORC unit adopting a radial-inflow turbo-expander. The results confirm the potential of the proposed method over the conventional iterative design practice for the design of small-scale ORC turbogenerators.

Integrated Design Methodology for High-Precision/Speed Servomechanisms

2005 ◽  
Vol 219 (8) ◽  
pp. 843-852 ◽  
Author(s):  
M-S Kim ◽  
S-C Chung
Keyword(s):  
High Precision ◽  
Design Method ◽  
Integrated Design ◽  
Design Procedure ◽  
Optimization Method ◽  
Design Variables ◽  
Mechanical Subsystem ◽  
Speed Performance ◽  
Parametric Studies ◽  
Design Requirements

An integrated design method for a high-precision/speed servomechanism including interactions of mechanical and electrical subsystems is proposed in this article. On the basis of the multiobjective optimization method, a non-linear optimal design procedure of the mechanical subsystem is performed simultaneously through the design process of the electrical subsystem satisfying the desired performance. Mechanical and electrical constraints have been formulated according to design requirements. Both mechanical and electrical parameters are considered as design variables. Validity of the integrated design problem is verified on the different application areas. Parametric studies of the design variables have also been conducted in this article. Case studies show that the integrated design method for an x-y positioning system satisfies the desired high-precision/speed performance.

A Design Method of Radial Fans Considering the Torque-Speed-Characteristic of the Motor

2010 ◽  
Author(s):  
Philipp Epple ◽  
Mihai Miclea ◽  
Klaus Pfannschmidt ◽  
Detlev Grobeis ◽  
Antonio Delgado
Keyword(s):  
High Speed ◽  
Design Method ◽  
Design Procedure ◽  
Design Stage ◽  
Maximum Efficiency ◽  
Cfd Analysis ◽  
Test Rig ◽  
Motor Design ◽  
Line Design ◽  
Speed Characteristic

The use of high speed radial impellers is very common in fans for industrial applications. The most common design case is the one with constant speed. In that case, one assigns the corresponding value to the speed n, hence the speed no longer matters in the further design procedure: it is given and it is constant. However, in many cases the speed is not constant, since it is governed by the torque-speed characteristic of the driving motor. In such a case it is necessary to consider the motor characteristic already at the design stage. In the present work a design method was developed in order to perfectly match the torque-speed characteristic of the radial impeller to the torque-speed characteristic of the driving motor. In such a way it is possible to design an impeller-motor unit with maximum efficiency. The extended impeller mean-line-design formulas presented in Epple [6] were complemented with the equations describing the motor torque-speed-characteristic. Both sets of equations where combined and solved in order to achieve a prescribed operating range at a maximum efficiency. In order to validate the design method, it was applied to an industrial fan which should be improved. That radial fan with spiral casing consisted of the main radial fan and a motor cooling axial fan at the other end of the shaft. This later fan was rotating at a too low speed leading to cooling problems of the motor. Hence, a new fan had to be designed which had to deliver the same hydraulic performance but at higher rotating speeds. This had to be done, however, on the given motor. That could only be done when properly designing an impeller matching its torque-speed characteristic to the torque-speed characteristic of the motor: it was an excellent task to validate the combined impeller-motor design procedure. Under these constrains six designs where performed and validated with a commercial CFD solver. The three best designs according to the CFD results were built as prototypes and measured at a standard test rig. The best design delivered the prescribed head-flow characteristic at an even improved hydraulic efficiency. The higher speed was also properly achieved. The design procedure is described and explained in detail and a detailed CFD analysis is presented, complemented by the experimental data obtained at the test rig. A final comparative analysis of the combined impeller-motor design method, the CFD analysis and the measurements is presented.

Root Sum Squares Tolerance Analysis with Nonlinear Problems

1990 ◽  
Vol 112 (4) ◽  
pp. 382-384 ◽  
Author(s):  
W. H. Greenwood ◽  
K. W. Chase
Keyword(s):  
Statistical Analysis ◽  
Design Method ◽  
Design Procedure ◽  
Nonlinear Problems ◽  
Tolerance Analysis ◽  
Iterative Design ◽  
Independent Variables

Elementary tolerance analysis with nonlinear assembly equations or functions can lead to significant errors when either Worst Limits or Root Sum Squares are applied. A previous paper [1] presented the errors and a corrective design method for Worst Limit elementary tolerance analysis. In this paper, Root Sum Squares tolerance analysis is applied to a nonlinear assembly equation, which gives significant errors in the assembly acceptance fraction. Advanced statistical analysis can be used in an iterative design procedure to specify the independent variables which meet the specified assembly in spite of the nonlinearities.

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