Optimal Design of High-Speed Partial Flow Pumps using Orthogonal Tests and Numerical Simulations

To investigate the influence of structural parameters on the performances and internal flow characteristics of partial flow pumps at a low specific speed of 10000 rpm,special attention was paid to the first and second stage impeller guide vanes.Moreover,the impeller blade outlet width,impeller inlet diameter,blade inclination angle,and number of blades were considered for orthogonal tests.Accordingly,nine groups of design solutions were formed,and then used as a basis for the execution of numerical simulations(CFD)aimed at obtaining the efficiency values and heads for each design solution group.The influence of impeller geometric parameters on the efficiency and head was explored,and the“weight”of each factor was obtained via a range analysis.Optimal structural parameters were finally chosen on the basis of the numerical simulation results,and the performances of the optimized model were verified accordingly(yet by means of CFD).Evidence is provided that the increase in the efficiency and head of the optimized model was 12.11%and 23.5 m,respectively,compared with those of the original model.

Innovative Techniques Unveiled in Advanced Sheet Pile Curtain Design

This thorough review explores the complexities of geotechnical engineering, emphasizing soil-structure interaction (SSI). The investigation centers on sheet pile design, examining two primary methodologies: Limit Equilibrium Methods (LEM) and Soil-Structure Interaction Methods (SSIM). While LEM methods, grounded in classical principles, provide valuable insights for preliminary design considerations, they may encounter limitations in addressing real-world complexities. In contrast, SSIM methods, including the SSI-SR approach, introduce precision and depth to the field. By employing numerical techniques such as Finite Element (FE) and Finite Difference (FD) analyses, these methods enable engineers to navigate the dynamics of soil-structure interaction. The exploration extends to SSI-FE, highlighting its essential role in civil engineering. By integrating Finite Element analysis with considerations for soil-structure interaction, the SSI-FE method offers a holistic understanding of how structures dynamically interact with their geotechnical environment. Throughout this exploration, the study dissects critical components governing SSIM methods, providing engineers with tools to navigate the intricate landscape of geotechnical design. The study acknowledges the significance of the Mohr-Coulomb constitutive model while recognizing its limitations, and guiding practitioners toward informed decision-making in geotechnical analyses. As the article concludes, it underscores the importance of continuous learning and innovation for the future of geotechnical engineering. With advancing technology and an evolving understanding of soil-structure interaction, the study remains committed to ensuring the safety, stability, and efficiency of geotechnical structures through cutting-edge design and analysis techniques.

Product Specification Analysis for Modular Product Design Using Big Sales Data

Big data on product sales are an emerging resource for supporting modular product design to meet diversified customers’requirements of product specification combinations.To better facilitate decision-making of modular product design,correlations among specifications and components originated from customers’conscious and subconscious preferences can be investigated by using big data on product sales.This study proposes a framework and the associated methods for supporting modular product design decisions based on correlation analysis of product specifications and components using big sales data.The correlations of the product specifications are determined by analyzing the collected product sales data.By building the relations between the product components and specifications,a matrix for measuring the correlation among product components is formed for component clustering.Six rules for supporting the decision making of modular product design are proposed based on the frequency analysis of the specification values per component cluster.A case study of electric vehicles illustrates the application of the proposed method.

Structural design and modal behaviors analysis of a new swept baffled inflatable wing

Inflatable wing has significant application value in the design of loitering munitions because of its advantages such as lightweight and foldability.However,due to the flexible characteristics,aeroelastic behaviors of inflatable wings such as flutter are nonnegligible in flight.By designing a certain angle between the inflatable beam and the wing span,the structural dynamic and even the aeroelastic performance of the inflatable wing can be effectively improved.Based on the analysis of the mechanical and geometric characteristics of the inflatable structure,a new inflatable wing with sweep arranged inflatable beams is proposed,and the main design variables and methods are analyzed.For purpose of investigating the aeroelastic performance of the swept baffled inflatable wing,the modal behaviors by considering the wet mode are studied.In consideration of the deficiencies of the traditional wet modal analysis method,by introducing the influence on the additional stiffness of flow field,an added massstiffness method is proposed in this paper,and the advantages are verified by ground vibration experiments.On this basis,the effects of baffles sweep angle,pressure,and boundary conditions on the modal parameters and aeroelastic performance of inflatable wing are analyzed.The results show that the aeroelastic performance of the inflatable wing can be designed by changing the baffles sweep angle,which is enlightened for the aeroelastic tailoring design on inflatable wings.

Convergence Analysis of the Numerical Solution for Cathode Design of Aero-engine Blades in Electrochemical Machining

As a main difficult problem encountered in electrochemical machining （ECM）, the cathode design is tackled, at present, with various numerical analysis methods such as finite difference, finite element and boundary element methods. Among them, the finite element method presents more flexibility to deal with the irregularly shaped workpieces. However, it is very difficult to ensure the convergence of finite element numerical approach. This paper proposes an accurate model and a finite element numerical approach of cathode design based on the potential distribution in inter-electrode gap. In order to ensure the convergence of finite element numerical approach and increase the accuracy in cathode design, the cathode shape should be iterated to eliminate the design errors in computational process. Several experiments are conducted to verify the machining accuracy of the designed cathode. The experimental results have proven perfect convergence and good computing accuracy of the proposed finite element numerical approach by the high surface quality and dimensional accuracy of the machined blades.

Structural Design and Numerical Analysis of a Novel Biodegradable Zinc Alloy Stent

Biodegradable zinc alloy stents are a prospective solution for complications caused by the incompatibility between artery and permanent stents.However,insufficient scaffolding has limited the clinical application of biodegradable zinc alloy stents.Therefore,in this study,a new stent concept was designed to improve the scaffolding.The mechanical performances of the new and a traditional design stent were investigated and compared using finite element analysis(FEA).The new and traditional design stent were expanded to the intended radial displacement of 0.24 mm under the expansion pressure of 0.58 MPa and 0.45 MPa,respectively.Then,a pressure load of 0.35 MPa was exerted on the outer surfaces of the two stents to compress them.The results showed that the radial recoiling ratio were 45.3%and 83.3%for the new and the traditional stent,respectively.The simulations demonstrate that the biodegradable zinc alloy stent offers enhanced support because of the new structural design.This study implies that biodegradable zinc alloy stent can be a new competitive intervention device for the future clinical cardiovascular application.

Design and analysis of a high loss density motor cooling system with water cold plates

Aiming at reducing the difficulty of cooling the interior of high-density motors,this study proposed the placement of a water cold plate cooling structure between the axial laminations of the motor stator.The effect of the cooling water flow,thickness of the plate,and motor loss density on the cooling effect of the water cold plate were studied.To compare the cooling performance of water cold plate and outer spiral water jacket cooling structures,a high-speed permanent magnet motor with a high loss density was used to establish two motor models with the two cooling structures.Consequently,the cooling effects of the two models were analyzed using the finite element method under the same loss density,coolant flow,and main dimensions.The results were as follows.(1)The maximum and average temperatures of the water cold plate structure were reduced by 25.5%and 30.5%,respectively,compared to that of the outer spiral water jacket motor;(2)Compared with the outer spiral water jacket structure,the water cold plate structure can reduce the overall mass and volume of the motor.Considering a 100 kW high-speed permanent magnet motor as an example,a water cold plate cooling system was designed,and the temperature distribution is analyzed,with the result indicating that the cooling structure satisfied the cooling requirements of the high loss density motor.

Applying UML and Machine Learning to Enhance System Analysis and Design

System analysis and design (SAD) is a crucial process in the development of software systems. The impact of modeling techniques and software engineering practices on SAD has been the focus of research for many years. Two such techniques that have had a significant impact on SAD are Unified Modeling Language (UML) and machine learning. UML has been used to model the structure and behavior of software systems, while machine learning has been used to automatically learn patterns in data and make predictions. The purpose of this paper is to review the literature on the impact of UML and machine learning on SAD. We summarize the findings from several studies and highlight the key insights related to the benefits and limitations of these techniques for SAD. Our review shows that both UML and machine learning have had a positive impact on SAD, with UML improving communication and documentation, and machine learning improving the accuracy of predictions. However, there are also challenges associated with their use, such as the need for expertise and the difficulty of interpreting machine learning models. Our findings suggest that a combination of UML and machine learning can enhance SAD by leveraging the strengths of each technique.

Finding Symbolic and All Numerical Solutions for Design Optimization Based on Monotonicity Analysis and Solving Polynomial Systems

A method for determining symbolic and all numerical solutions in design optimization based on monotonicity analysis and solving polynomial systems is presented in this paper. Groebner Bases of the algebraic system equivalent to the subproblem of the design optimization is taken as the symbolic (analytical) expression of the optimum solution for the symbolic optimization, i.e. the problem with symbolic coefficients. A method based on substituting and eliminating for determining Groebner Bases is also proposed, and method for finding all numerical optimum solutions is discussed. Finally an example is given, demonstrating the strategy and efficiency of the method.

Vibration Control of the Rail Grinding Vehicle with Abrasive Belt Based on Structural Optimization and Lightweight Design

As a new grinding and maintenance technology,rail belt grinding shows significant advantages in many applications The dynamic characteristics of the rail belt grinding vehicle largely determines its grinding performance and service life.In order to explore the vibration control method of the rail grinding vehicle with abrasive belt,the vibration response changes in structural optimization and lightweight design are respectively analyzed through transient response and random vibration simulations in this paper.Firstly,the transient response simulation analysis of the rail grinding vehicle with abrasive belt is carried out under operating conditions and non-operating conditions.Secondly,the vibration control of the grinding vehicle is implemented by setting vibration isolation elements,optimizing the structure,and increasing damping.Thirdly,in order to further explore the dynamic characteristics of the rail grinding vehicle,the random vibration simulation analysis of the grinding vehicle is carried out under the condition of the horizontal irregularity of the American AAR6 track.Finally,by replacing the Q235 steel frame material with 7075 aluminum alloy and LA43M magnesium alloy,both vibration control and lightweight design can be achieved simultaneously.The results of transient dynamic response analysis show that the acceleration of most positions in the two working conditions exceeds the standard value in GB/T 17426-1998 standard.By optimizing the structure of the grinding vehicle in three ways,the average vibration acceleration of the whole car is reduced by about 55.1%from 15.6 m/s^(2) to 7.0 m/s^(2).The results of random vibration analysis show that the grinding vehicle with Q235 steel frame does not meet the safety conditions of 3σ.By changing frame material,the maximum vibration stress of the vehicle can be reduced from 240.7 MPa to 160.0 MPa and the weight of the grinding vehicle is reduced by about 21.7%from 1500 kg to 1175 kg.The modal analysis results indicate that the vibration control of the grinding vehicle can be realized by optimizing the structure and replacing the materials with lower stiffness under the premise of ensuring the overall strength.The study provides the basis for the development of lightweight,diversified and efficient rail grinding equipment.

Analysis of the Application of Ink Art in Graphic Design Imagery

The graphic design industry has been developing rapidly in recent years.People have begun to focus on steering the development of graphic design in the direction of localization,integrating more traditional Chinese elements,raising the level of acceptance toward graphic design content,and disseminating traditional culture on this basis.Ink art plays an important role in the historical and cultural development process.It uses simple color contrast to construct different situations and possesses unique artistic charm and cultural heritage.Incorporating ink elements into graphic design may enhance the graphic design style and provide inspiration.This article focuses on the reasons,advantages,and strategies of using ink art in graphic design imagery,hoping to provide references for graphic design activities.

Impact Performance Research of Re-Entrant Octagonal Negative Poisson’s Ratio Honeycomb with Gradient Design

Based on the traditional re-entrant honeycomb,a novel re-entrant octagon honeycomb(ROH)is proposed.The deformation mode of the honeycomb under quasi-static compression is analyzed by numerical simulation,and the results are in good agreement with the experimental ones.The deformation modes,mechanical properties,and energy absorption characteristics of ROH along the impact and perpendicular directions gradient design are investigated under different velocities.The results indicated that the deformation mode of ROH is affected by gradient design along the direction of impact and impact speed.In addition,gradient design along the direction of impact can increase the initial peak stress of ROH and accelerate its densification phase.Gradient design perpendicular to the impact direction can enhance the energy absorption performance of ROH,especially for ROH,with wall thickness increasing from the inside outwards.Compared to ROH with uniform wall thickness at the same relative density,ROH with a gradient design can increase the plateau stress by over half.With the elevation of impact velocity,the plateau stress and specific energy absorption exhibit an upward trend,aligning with the dynamic performance pattern observed in conventional honeycombs.The results can be used as a reference for the design and application of honeycomb and provide a new idea for developing more efficient and reliable energy-absorbing materials.

Flexible Fixture Design for the Top and End Surface Processing of NP2_NP4 Cylinder Heads

This paper focuses on the design of fixtures for NP2 and NP4 cylinder heads on a horizontal machining center of flexible machining automatic lines.It began with an analysis of the diagrams of part processing and working procedure which formed the basis for the design of the processing technology scheme,a selection of suitable machine tools,and the setting of processing parameters.Fixtures tailored to the chosen machine tools were then designed to meet the processing requirements.Additional aspects of the project included the design of part drawings,calculation of working time quota,design of auxiliary guides,support clamping,and hydraulic circuits,all aimed at fulfilling practical production requirements.

基于Cast Designer的壳体铸件铸造工艺设计及智能优化

使用Cast Designer铸造仿真分析软件,通过可铸性评估系统DFM,完成浇冒系统的辅助设计,然后使用DOE技术和基于遗传算法GA的智能优化技术,评估不同工艺设计方案与铸造过程参数对壳体铸件质量的影响,分析在不同的冒口、冷铁和浇注温度条件下得料率和缩孔量的关系。根据对DOE模拟结果的分析,发现顶冒口和侧冒口尺寸是影响得料率和缩孔量的关键因数,再利用遗传算法GA选择最佳设计方案和参数。通过帕累托曲线得到了生产壳体铸件的最优工艺方案。

基于MATLAB App Designer的加工误差统计分析实验系统设计

机械加工误差的统计分析是机械制造基础课程中典型的实验内容,同时也是机械专业生产实习期间评定工艺过程加工精度的重要巩固环节。为了使学生从理论更直接地过渡到实际应用中,改善传统实验教学手段的单一化,设计了一种基于MATLAB App Designer的加工误差统计分析实验系统。该系统针对多个常见工序随机产生能够模拟真实工序尺寸的样本,并引导学生按照实验步骤完成工艺过程的分布图法分析与点图法分析。实验过程中可随时查看分数,学生可反思纠错、反复练习。同时提供了可用于参考的测量尺寸频数分布图、x−R图,能帮助学生灵活直观地掌握加工误差的统计分析原理与应用过程,提高实验教学的水平。

Assessment of the stiffened panel performance in the OTEC seawater tank design:Parametric study and sensitivity analysis

Ocean thermal energy conversion(OTEC)is a process of generating electricity by exploiting the temperature difference between warm surface seawater and cold deep seawater.Due to the high static and dynamic pressures that are caused by seawater circulation,the stiffened panel that constitutes a seawater tank may undergo a reduction in ultimate strength.The current paper investigates the design of stiffening systems for OTEC seawater tanks by examining the effects of stiffening parameters such as stiffener sizes and span-over-bay ratio for the applied combined loadings of lateral and transverse pressure by fluid motion and axial compression due to global bending moment.The ultimate strength calculation was conducted by using the non-linear finite element method via the commercial software known as ABAQUS.The stress and deformation distribution due to pressure loads was computed in the first step and then brought to the second step,in which the axial compression was applied.The effects of pressure on the ultimate strength of the stiffener were investigated for representative stiffened panels,and the significance of the stiffener parameters was assessed by using the sensitivity analysis method.As a result,the ultimate strength was reduced by approximately 1.5%for the span-over-bay ratio of 3 and by 7%for the span-over-bay ratio of 6.

The Survey on Course Design for Business English Majors on the Base of Needs Analysis

Based on the needs analysis theory, a survey on the course design of Business English at Honghe University are conducted. Business English majors' learning needs and attitudes towards course design of Business English are researched through questionnaires. Business English competences needed in workplaces and society's needs for Business English talents are investigated. After analyzing recruitment information for Business English talents collected from domestic credible websites, some suggestions on course design of business English are supplied.

Site Analysis of Residential Community Design—A Case Study of the Residential Community of the Fifth Agricultural Construction Division in Bole City of Xinjiang Uygur Autonomous Region in China

Based on the concept of site characteristic and site spirit,by taking the Residential Community of the Fifth Agricultural Construction Division in Bole City of Xinjiang Uygur Autonomous Region for example,the paper has analyzed its background and general situation,and the site characteristic,and emphasized that its planning and design should manifest the comfortable and cozy environment of the residential community,army culture unique in the Fifth Agricultural Division of Xinjiang Crops,and its enterprising spirit.It has pointed out the design should highlight people orientation;stress the quality of living environment;emphasize the individuality of the residential community;combine new technologies;respect the sunshine,terrain and waterscape of the site;well deal with the spatial location of the site;and pay attention to the inheritance of historical culture in the site,so as to create a high-grade residential community integrating army crops feature and water style,with complete supporting facilities,and in possession of unique sharing space,broad landscape avenue and wide building span.

Detailed Statistic Analysis Method of Split-split Plot Design in Agricultural Research

Based on a practical research test, the statistic analysis method for the experimental data in the split-split plot design was introduced in detail, especially in- troduced the significant test method of three-factor interaction and the calculation of test value, which solved the problem of how to make statistical analysis on the data in split-split plot design.

ELT Materials Design of a Speaking Unit based on Needs Analysis

In this article,the authors design a speaking unit based on needs analysis following Hutchinson and Waters'(1987) model.First,the rationale in designing this unit is introduced,which involves the teaching approach adopted and relevant theories in organizing the materials.Then,the teaching plan of this speaking unit is provided and some activities are designed to create an authentic and optimal situation for students to practice their speaking skill.