scholarly journals Design Method for Contra-Rotating Propellers for High-Speed Crafts: Revising the Original Lerbs Theory in a Modern Perspective

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
Stefano Brizzolara ◽  
Davide Grassi ◽  
Emilio P. Tincani
Keyword(s):  
High Speed ◽  
Design Theory ◽  
Design Method ◽  
Design Parameters ◽  
Strength Criteria ◽  
New Methods ◽  
Modified Method ◽  
Circulation Distribution ◽  
Pod Propulsor ◽  
Modern Perspective

The main theoretical and numerical aspects of a design method for optimum contrar-rotating (CR) propellers for fast marine crafts are presented. We propose a reformulated version of a well-known design theory for contra-rotating propellers, by taking advantage of a new fully numerical algorithm for the calculation of the mutually induced velocities and introducing new features such as numerical lifting surface corrections, use of an integrated modern cavitation/strength criteria, a modified method to consider different numbers of blades among the two propellers, and to allow for an unloading function in the search for the optimal circulation distribution. The paper first introduces the main theoretical principles of the new methods and then discusses the influence of the main design parameters on an emblematic example of application in the case of counter rotating propellers for a pod propulsor designed for fast planing crafts (35 knots and above).

Development of High-Speed Response Electromagnetic Linear Actuator Using for Pneumatic Control Valve

2014 ◽  
Vol 532 ◽  
pp. 41-45 ◽  
Author(s):  
Myung Jin Chung
Keyword(s):  
Optimal Design ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Design Method ◽  
Control Valve ◽  
Design Parameters ◽  
Linear Actuator ◽  
Analytic Model ◽  
Electromagnetic Linear Actuator ◽  
Quadratic Programming Method

Analytic model of electromagnetic linear actuator in the function of electric and geometric parameters is proposed and the effects of the design parameters on the dynamic characteristics are analyzed. To improve the dynamic characteristics, optimal design is conducted by applying sequential quadratic programming method to the analytic model. This optimal design method aims to minimize the response time and maximize force efficiency. By this procedure, electromagnetic linear actuator having high-speed characteristics is developed.

A 3D Automatic Optimization Strategy for Design of Centrifugal Compressor Impeller Blades

1998 ◽  
Author(s):  
K. F. C. Yiu ◽  
M. Zangeneh
Keyword(s):  
Numerical Optimization ◽  
Design Method ◽  
Design Parameters ◽  
Optimization Strategy ◽  
Compressor Blades ◽  
Automatic Optimization ◽  
Compressor Impeller ◽  
Circulation Distribution ◽  
Actual Profile ◽  
Inverse Design Method

In deriving automatic numerical optimization algorithms for aerodynamic applications, the design parameters are usually chosen to be the unknown airfoil/blade profiles. However, there are certain advantages in using the pressure/velocity distribution as the design variable in some applications; the designed distribution can then be used in a 3D inverse design method to generate the actual profile shape. Here, this approach will be addressed. Two methods are used to parametrize the circulation distribution for compressor blades. Dawes’s code is used to predict the viscous effect. An automatic optimization algorithm is developed to minimize the loss with respect to the design parameters.

scholarly journals Optimization of Meridional Flow Channel Design of Pump Impeller

2004 ◽  
Vol 10 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Sunao Miyauchi ◽  
Hironori Horiguchi ◽  
Jun-ichirou Fukutomi ◽  
Akihiro Takahashi
Keyword(s):  
Design Method ◽  
Three Dimensional ◽  
Optimization Method ◽  
Meridional Flow ◽  
Flow Channel ◽  
Design Parameters ◽  
Channel Design ◽  
Pump Impeller ◽  
Circulation Distribution ◽  
Meridional Shape

The meridional flow channel design of a pump impeller affects its performance. However, since so many design parameters exist, a new design method is proposed in which a meridional and blade-to-blade flow channel is designed by the parallel use of the circulation distribution provided by the designer. Thus, an optimization method was used to design an axis-symmetrical meridional flow channel from the circulation distribution. In addition, the inverse design method proposed by Zangeneh et al. (1996) was employed to design a three-dimensional blade-to-blade flow channel from the circulation distribution and the optimized meridional shape. In this article, a few design examples and these Computational Fluid Dynamics (CFD) validations are also given.

Rapid Design of Low-Voltage Motor Protector Based on Axiomatic Theory

2011 ◽  
Vol 84-85 ◽  
pp. 415-420
Author(s):  
Li Yun Xu ◽  
Hai Jiang Chen ◽  
Ai Ping Li ◽  
Andrea Matta
Keyword(s):  
Design Theory ◽  
Low Voltage ◽  
Design Method ◽  
Design Parameters ◽  
Systematic Design ◽  
Functional Requirements ◽  
Axiomatic Theory ◽  
Independent Functions ◽  
Mapping Process ◽  
Axiomatic Design Theory

Facing the diversified demands and design complexity, a systematic design method for low-voltage motor protector is proposed based on axiomatic design theory, which integrates with design constraints and expert's knowledge. Zigzagging mapping between functional requirements and design parameters is obtained by the top-to-down decomposition according to the customer's needs, and the hierarchy of independent functions is also built. Systematic chart and mapping process are also analyzed in order to simplify the design process for different designers. Finally, a case of motor protector of LM5 series is illustrated to verify the method’s feasibility and effectiveness.

scholarly journals Optimal Design of High-Power Medium-Frequency Transformer Using Hollow Conductors with Consideration of Multi-Objective Parameters

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3654
Author(s):  
Yunxiang Guo ◽  
Cheng Lu ◽  
Liang Hua ◽  
Xinsong Zhang
Keyword(s):  
Optimal Design ◽  
High Power ◽  
High Speed ◽  
Comprehensive Evaluation ◽  
Design Method ◽  
System Structure ◽  
Design Parameters ◽  
Medium Frequency ◽  
Evaluation Standard ◽  
Leakage Inductance

A power electronic transformer (PET) is applied to the high-speed train for lightweight demand. A 300 kW/5 kHz high-power medium-frequency transformer (HPMFT) using hollow conductors in a power unit of the PET is optimally designed in this paper. The target of the design is to balance the loss, leakage inductance, and weight of the HPMFT. For this purpose, the design parameters of the HPMFT are firstly confirmed according to the system structure and parameters of the PET. Secondly, the design process of HPMFT is developed. Finally, the results of 48 design schemes of core-type and shell-type structures are compared by the comprehensive evaluation standard, which equilibrates the three above objective parameters of the HPMFT. According to the optimal scheme, a prototype is manufactured, whose test results verify the correctness of the optimal design method.

Research on coordination design method of main bearing assembly structure based on the maximum radial deformation of bearing bush

2021 ◽  
pp. 146808742110409
Author(s):  
Xin Zhao ◽  
Tiexiong Su ◽  
Xiaoyong Liu ◽  
Yunpeng Feng
Keyword(s):  
High Speed ◽  
Design Method ◽  
Design Parameters ◽  
Radial Deformation ◽  
Main Bearing ◽  
Tightening Force ◽  
Assembly Structure ◽  
Bearing Assembly ◽  
Numerical Calculation Method ◽  
Coordination Design

Aiming at the difficulty of control and evaluation of main bearing deformation in the coordination design of the main bearing assembly structure for a high-speed diesel engine, taking MRD (the MRD means the maximum radial deformation of the bearing bush) of the bearing bush as an index to evaluate the out-of-round deformation of the bearing bush was proposed in this paper. The numerical calculation method of the MRD was given and the correctness of the method was experimentally verified. And the influence rules of different design parameters on the MRD were analyzed. On this basis, the coordination multi-objective optimization research of the main bearing assembly structure was carried out, and the optimization results were analyzed based on the influence rules of different design parameters on the reliability indexes. The results show that, when the pre-tightening force of the vertical bolt and the bearing bush interference are 240 kN and 0.17 mm respectively, the MRD reaches the minimum value. If the two values continue to increase, redundant loads can be generated, leading to the increase of the MRD. After optimization, the engine block strength coordination and bearing cap strength coordination had increased by 2.47% and 10.48%, respectively, and the deformation coordination and contact coordination had increased by 46.15% and 14.84%, respectively.

scholarly journals A Systematic Optimization Design Method for Complex Mechatronic Products Design and Development

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Jie Jiang ◽  
Guofu Ding ◽  
Jian Zhang ◽  
Yisheng Zou ◽  
Shengfeng Qin
Keyword(s):  
High Speed ◽  
Optimization Design ◽  
Design Space ◽  
Design Method ◽  
Evaluation Criteria ◽  
Research Problem ◽  
Optimization Techniques ◽  
Design Parameters ◽  
Space Reduction ◽  
Systematic Optimization

Designing a complex mechatronic product involves multiple design variables, objectives, constraints, and evaluation criteria as well as their nonlinearly coupled relationships. The design space can be very big consisting of many functional design parameters, structural design parameters, and behavioral design (or running performances) parameters. Given a big design space and inexplicit relations among them, how to design a product optimally in an optimization design process is a challenging research problem. In this paper, we propose a systematic optimization design method based on design space reduction and surrogate modelling techniques. This method firstly identifies key design parameters from a very big design space to reduce the design space, secondly uses the identified key design parameters to establish a system surrogate model based on data-driven modelling principles for optimization design, and thirdly utilizes the multiobjective optimization techniques to achieve an optimal design of a product in the reduced design space. This method has been tested with a high-speed train design. With comparison to others, the research results show that this method is practical and useful for optimally designing complex mechatronic products.

Aerodynamic and aeroacoustic performance investigations on modified H-rotor Darrieus wind turbine

2021 ◽  
pp. 0309524X2110039
Author(s):  
Amgad Dessoky ◽  
Thorsten Lutz ◽  
Ewald Krämer
Keyword(s):  
Wind Turbine ◽  
High Speed ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
3D Models ◽  
Power Coefficient ◽  
Design Parameters ◽  
Second Phase ◽  
Vertical Axis Wind Turbine ◽  
Guide Vanes

The present paper investigates the aerodynamic and aeroacoustic characteristics of the H-rotor Darrieus vertical axis wind turbine (VAWT) combined with very promising energy conversion and steering technology; a fixed guide-vanes. The main scope of the current work is to enhance the aerodynamic performance and assess the noise production accomplished with such enhancement. The studies are carried out in two phases; the first phase is a parametric 2D CFD simulation employing the unsteady Reynolds-averaged Navier-Stokes (URANS) approach to optimize the design parameters of the guide-vanes. The second phase is a 3D CFD simulation of the full turbine using a higher-order numerical scheme and a hybrid RANS/LES (DDES) method. The guide-vanes show a superior power augmentation, about 42% increase in the power coefficient at λ = 2.75, with a slightly noisy operation and completely change the signal directivity. A remarkable difference in power coefficient is observed between 2D and 3D models at the high-speed ratios stems from the 3D effect. As a result, a 3D simulation of the capped Darrieus turbine is carried out, and then a noise assessment of such configuration is assessed. The results show a 20% increase in power coefficient by using the cap, without significant change in the noise signal.

scholarly journals A modular design method based on TRIZ and AD and its application to cutter changing robot

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110343
Author(s):  
Mei Yang ◽  
Yimin Xia ◽  
Lianhui Jia ◽  
Dujuan Wang ◽  
Zhiyong Ji
Keyword(s):  
Modular Design ◽  
Design Method ◽  
Idea Generation ◽  
Design Parameters ◽  
Problem Analysis ◽  
Concept Design ◽  
Functional Requirements ◽  
Shield Tunneling ◽  
Structural Hierarchy ◽  
And Performance

Modular design, Axiomatic design (AD) and Theory of inventive problem solving (TRIZ) have been increasingly popularized in concept design of modern mechanical product. Each method has their own advantages and drawbacks. The benefit of modular design is reducing the product design period, and AD has the capability of problem analysis, while TRIZ’s expertise is innovative idea generation. According to the complementarity of these three approaches, an innovative and systematic methodology is proposed to design big complex mechanical system. Firstly, the module partition is executed based on scenario decomposition. Then, the behavior attributes of modules are listed to find the design contradiction, including motion form, spatial constraints, and performance requirements. TRIZ tools are employed to deal with the contradictions between behavior attributes. The decomposition and mapping of functional requirements and design parameters are carried out to construct the structural hierarchy of each module. Then, modules are integrated considering the connections between each other. Finally, the operation steps in application scenario are designed in temporal and spatial dimensions. Design of cutter changing robot for shield tunneling machine is taken as an example to validate the feasibility and effectiveness of the proposed method.

scholarly journals Calculation Method of Permanent Deformation of Asphalt Mixture Based on Interval Number

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2116
Author(s):  
Yue Xiao ◽  
Limin Tang ◽  
Jiawei Xie
Keyword(s):  
Interval Analysis ◽  
Calculation Method ◽  
Design Theory ◽  
Permanent Deformation ◽  
Asphalt Mixture ◽  
Design Parameters ◽  
Interval Variable ◽  
Road Design ◽  
Weight Assignment ◽  
Variable Weight

There are great uncertainties in road design parameters, and the traditional point numerical calculation results cannot reflect the complexity of the actual project well. Additionally, the calculation method of road design theory based on interval analysis is more difficult in the use of uncertain design parameters. In order to simplify the calculation process of the interval parameters in the road design theory, the asphalt pavement design is taken as the analysis object, and the permanent deformation of the asphalt mixture is simplified by combining the interval analysis theory. Considering the uncertainty of the design parameters, the data with boundaries but uncertain size are expressed in intervals, and then the interval calculation formula for the permanent deformation of the asphalt mixture is derived, and the interval results are obtained. In order to avoid the dependence of interval calculation on the computer code, according to the interval calculation rule, the interval calculation method with the upper and lower end point values as point operations is proposed. In order to overcome the contradiction between interval expansion results and engineering applications, by splitting the multi-interval variable formulas, the interval variable weights are reasonably given, and the synthesis of each single interval result realizes a simplified calculation based on interval variable weight assignment. The analysis results show that the interval calculation method based on the point operation rule is accurate and reliable, and the simplified method based on the interval variable weight assignment is effective and feasible. The simplified interval calculation method proposed in this paper provides a reference for the interval application of road design theory.

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