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Cavitation Optimization for a Centrifugal Pump Impeller by Using Orthogonal Design of Experiment 被引量:6
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作者 PEI Ji YIN Tingyun +2 位作者 YUAN Shouqi WANG Wenjie WANG Jiabin 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第1期103-109,共7页
Cavitation is one of the most important performance of centrifugal pumps. However, the current optimization works of centrifugal pump are mostly focusing on hydraulic efficiency only, which may result in poor cavitati... Cavitation is one of the most important performance of centrifugal pumps. However, the current optimization works of centrifugal pump are mostly focusing on hydraulic efficiency only, which may result in poor cavitation performance. Therefore, it is necessary to find an appropriate solution to improve cavitation performance with acceptable efficiency. In this paper, to improve the cavitation performance of a centrifugal pump with a vaned diffuser, the influence of impeller geometric parameters on the cavitation of the pump is investigated using the orthogonal design of experiment (DOE) based on computational fluid dynamics. The impeller inlet diameter D1, inlet incidence angle Aft, and blade wrap angle ~0 are selected as the main impeller geometric parameters and the orthogonal experiment of L9(3"3) is performed. Three-dimensional steady simulations for cavitation are conducted by using constant gas mass fraction model with second-order upwind, and the predicated cavitation performance is validated by laboratory experiment. The optimization results are obtained by the range analysis method to improve cavitation performance without obvious decreasing the efficiency of the centrifugal pump. The internal flow of the pump is analyzed in order to identify the flow behavior that can affect cavitation performance. The results show that D1 has the greatest influence on the pump cavitation and the final optimized impeller provides better flow distribution at blade leading edge. The final optimized impeller accomplishes better cavitation and hydraulic performance and the NPSHR decreases by 0.63m compared with the original one. The presented work supplies a feasible route in engineering practice to optimize a centrifugal pump impeller for better cavitation performance. 展开更多
关键词 cavitation optimization computational fluid dynamics orthogonal design of experiment range analysis
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光学玻璃磨削亚表面损伤预测模型及DOE实验设计
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作者 杨晓辉 周凌宇 +1 位作者 刘宁 孟宪宇 《机械科学与技术》 CSCD 北大核心 2024年第3期520-525,共6页
为了掌握光学玻璃材料杯型砂轮研磨与表面粗糙度(SR)和亚表面损伤(SSD)机理,本文建立BK7光学玻璃杯型砂轮研磨表面粗糙度的预测模型,通过改变磨削参数来研究对表面粗糙度的影响。设计DOE试验,研究影响SR与SSD的显著性特征因子,并分析了... 为了掌握光学玻璃材料杯型砂轮研磨与表面粗糙度(SR)和亚表面损伤(SSD)机理,本文建立BK7光学玻璃杯型砂轮研磨表面粗糙度的预测模型,通过改变磨削参数来研究对表面粗糙度的影响。设计DOE试验,研究影响SR与SSD的显著性特征因子,并分析了各因子的交互作用。实验结果表明预测模型的可靠性,得到表面粗糙度的预测模型数据与实验数据的平均误差为5.47%。采用角抛光法,通过电子显微镜观测表面裂纹,并测量裂纹的深度。最后,基于Li的模型,建立基于磨削工艺参数的亚表面损伤的新预测模型。实验结果表明:实验和预测模型结果具有很好的一致性,模型数据与实验数据的平均误差为6.19%,并且新预测模型结果要优于Li的模型。 展开更多
关键词 表面粗糙度 亚表面损伤 BK7光学玻璃 预测模型 杯形砂轮磨削 doe实验设计
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Modeling Approach and Analysis of the Structural Parameters of an Inductively Coupled Plasma Etcher Based on a Regression Orthogonal Design 被引量:3
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作者 程嘉 朱煜 季林红 《Plasma Science and Technology》 SCIE EI CAS CSCD 2012年第12期1059-1068,共10页
The geometry of an inductively coupled plasma (ICP) etcher is usually considered to be an important factor for determining both plasma and process uniformity over a large wafer. During the past few decades, these pa... The geometry of an inductively coupled plasma (ICP) etcher is usually considered to be an important factor for determining both plasma and process uniformity over a large wafer. During the past few decades, these parameters were determined by the "trial and error" method, resulting in wastes of time and funds. In this paper, a new approach of regression orthogonal design with plasma simulation experiments is proposed to investigate the sensitivity of the structural parameters on the uniformity of plasma characteristics. The tool for simulating plasma is CFD-ACE+, which is commercial multi-physical modeling software that has been proven to be accurate for plasma simulation. The simulated experimental results are analyzed to get a regression equation on three structural parameters. Through this equation, engineers can compute the uniformity of the electron number density rapidly without modeling by CFD-ACE+. An optimization performed at the end produces good results. 展开更多
关键词 fluid model inductively coupled plasma regression orthogonal structural parameters design of experiment
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Mathematical model for abrasive suspension jet cutting based on orthogonal test design 被引量:5
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作者 胡贵华 朱文华 +5 位作者 蔡红霞 徐翀 柏余杰 程俊 苑进 俞涛 《Journal of Shanghai University(English Edition)》 CAS 2009年第1期37-44,共8页
This paper describes the application of orthogonal test design coupled with non-linear regression analysis to optimize abrasive suspension jet (AS J) cutting process and construct its cutting model. Orthogonal test ... This paper describes the application of orthogonal test design coupled with non-linear regression analysis to optimize abrasive suspension jet (AS J) cutting process and construct its cutting model. Orthogonal test design is applied to cutting stainless steel. Through range analysis on experiment results, the optimal process conditions for the cutting depth and the kerr ratio of the bottom width to the top width can be determined. In addition, the analysis of ranges and variances are all employed to identify various factors: traverse rate, working pressure, nozzle diameter, standoff distance which denote the importance order of the cutting parameters affecting cutting depth and the kerf ratio of the bottom width to the top width. ~rthermore, non-linear regression analysis is used to establish the mathematical models of the cutting parameters based on the cutting depth and the kerr ratio. Finally, the verification experiments of cutting parameters' effect on cutting performance, which show that optimized cutting parameters and cutting model can significantly improve the prediction of the cutting ability and quality of ASJ. 展开更多
关键词 abrasive suspension jet (AS J) orthogonal test design cutting depth the kerf ratio of the bottom width to the top width non-linear regression analysis verification experiment
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Computer modeling of high-pressure leaching process of nickel laterite by design of experiments and neural networks 被引量:1
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作者 Milovan Milivojevic Srecko Stopic +2 位作者 Bernd Friedrich Boban Stojanovic Dragoljub Drndarevic 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2012年第7期584-594,共11页
Due to the complex chemical composition of nickel ores, the requests for the decrease of production costs, and the increase of nickel extraction in the existing depletion of high-grade sulfide ores around the world, c... Due to the complex chemical composition of nickel ores, the requests for the decrease of production costs, and the increase of nickel extraction in the existing depletion of high-grade sulfide ores around the world, computer modeling of nickel ore leaching process be- came a need and a challenge. In this paper, the design of experiments (DOE) theory was used to determine the optimal experimental design plan matrix based on the D optimality criterion. In the high-pressure sulfuric acid leaching (HPSAL) process for nickel laterite in "Rudjinci" ore in Serbia, the temperature, the sulfuric acid to ore ratio, the stirring speed, and the leaching time as the predictor variables, and the degree of nickel extraction as the response have been considered. To model the process, the multiple linear regression (MLR) and response surface method (RSM), together with the two-level and four-factor full factorial central composite design (CCD) plan, were used. The proposed re- gression models have not been proven adequate. Therefore, the artificial neural network (ANN) approach with the same experimental plan was used in order to reduce operational costs, give a better modeling accuracy, and provide a more successful process optimization. The model is based on the multi-layer neural networks with the back-propagation (BP) learning algorithm and the bipolar sigmoid activation function. 展开更多
关键词 nickel laterite LEACHING computer simulation design of experiments doe response surface method (RSM) neural networks
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Design of Experiment (DoE): Implementation in Determining Optimum Design Parameters of Portable Workstation
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作者 Nafisa Ali Anika Nadia Tanzeem Himadri Sen Gupta 《Engineering(科研)》 2020年第1期25-32,共8页
In the modern era of manufacturing, it is important to optimize every design parameter in product development stage to reduce cost, material usage and to achieve the desired efficacy level. There are various models wh... In the modern era of manufacturing, it is important to optimize every design parameter in product development stage to reduce cost, material usage and to achieve the desired efficacy level. There are various models which serve those purposes, for instance, Design of Experiment (DoE) is used to check the parameters after adopting optimization tactics which results in reduced cost or saving operating time. In this regard, this research aims to construct a DoE model on a portable workstation to optimize its design parameters. The methodology of DOE would be a 2 level 3 factors full factorial DOE which is conducted to determine the optimal value for three design parameters (factors) which are material density, the length of the table and the length of the table stand in terms of the response which is the required time of fold ability function of the portable workstation. Based upon the evaluated interactions between the parameters, the optimized parameters are chosen for responses. Here, the resultant design parameters are at their lowest level, so the goal of time efficiency in fold ability function is achieved. This similar sort of DoE can be implemented in the furniture and other manufacturing industries who wish to optimize their material usage as well as increase efficiency and reduce cycle time. 展开更多
关键词 design of experiMENT (doe) PORTABLE WORKSTATION design Parameters Response Time Efficiency Improvement
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利用DOE实验设计方法模拟聚苯硫醚热氧处理的研究
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作者 周贵阳 吕林君 +2 位作者 连明 李沃源 张雄伟 《化工管理》 2024年第27期42-46,74,共6页
文章研究了聚苯硫醚热氧处理的模拟预测,利用MSA方法对熔体质量流动速率(MFR)的测试系统进行评估,并使用DOE实验设计方法模拟了聚苯硫醚热氧交联工艺。结果表明,对MFR不超过1000 g/10 min的样品,可以使用现有MFR测试系统得到可靠数据;根... 文章研究了聚苯硫醚热氧处理的模拟预测,利用MSA方法对熔体质量流动速率(MFR)的测试系统进行评估,并使用DOE实验设计方法模拟了聚苯硫醚热氧交联工艺。结果表明,对MFR不超过1000 g/10 min的样品,可以使用现有MFR测试系统得到可靠数据;根据JMP软件模拟可以得到PPS热氧交联过程的模型和交联产物MFR的计算公式。交联MFR随热空气温度升高而降低,但热空气温度接近或超过PPS树脂初熔点时,PPS树脂容易部分熔融、黏附在设备内壁或结块,影响交联反应;通过单因子验证实验,确定了模型的使用范围是热空气温度200~240℃、热处理时间大于20 h,模型偏差为-6.0%~6.2%。利用JMP软件指导PPS树脂的交联品生产,并进行DOE扩充设计,进一步建立实际生产用热氧处理模型,用于技术指导。 展开更多
关键词 聚苯硫醚 热氧交联 实验设计(doe) 测量系统分析(MSA)
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Solution for integer linear bilevel programming problems using orthogonal genetic algorithm 被引量:9
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作者 Hong Li Li Zhang Yongchang Jiao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第3期443-451,共9页
An integer linear bilevel programming problem is firstly transformed into a binary linear bilevel programming problem, and then converted into a single-level binary implicit programming. An orthogonal genetic algorith... An integer linear bilevel programming problem is firstly transformed into a binary linear bilevel programming problem, and then converted into a single-level binary implicit programming. An orthogonal genetic algorithm is developed for solving the binary linear implicit programming problem based on the orthogonal design. The orthogonal design with the factor analysis, an experimental design method is applied to the genetic algorithm to make the algorithm more robust, statistical y sound and quickly convergent. A crossover operator formed by the orthogonal array and the factor analysis is presented. First, this crossover operator can generate a smal but representative sample of points as offspring. After al of the better genes of these offspring are selected, a best combination among these offspring is then generated. The simulation results show the effectiveness of the proposed algorithm. 展开更多
关键词 integer linear bilevel programming problem integer optimization genetic algorithm orthogonal experiment design
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基于DOE的加工汽车碳纤维材料的新型钻头设计与优化
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作者 汪洋 杨兰杰 《汽车零部件》 2023年第2期15-20,共6页
针对加工汽车碳纤维材料的钻头寿命短、加工质量差的问题,设计了一种新型钻头。通过DOE(design of experiment)试验方法,给出了钻头齿数、前角和后角等3个参数的全因子试验方案。利用MINITAB软件对试验数据进行回归分析,并利用响应优化... 针对加工汽车碳纤维材料的钻头寿命短、加工质量差的问题,设计了一种新型钻头。通过DOE(design of experiment)试验方法,给出了钻头齿数、前角和后角等3个参数的全因子试验方案。利用MINITAB软件对试验数据进行回归分析,并利用响应优化获得最优设计参数。结果表明:齿数和后角对钻孔个数及钻头寿命影响不显著,前角对钻头寿命有显著影响,后角与前角的交互作用对钻头寿命也有显著影响。齿数、前角和后角对第一孔钻孔时间及钻孔速度有显著影响,齿数与后角的交互作用以及前角与后角的交互作用对钻孔速度有显著影响。通过试验测试验证优化后的最佳设计参数是有效合理的。 展开更多
关键词 碳纤维 钻头 试验设计 回归分析 优化响应
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Design of experiment study on hardness variations in friction stir welding of AM60 Mg alloy 被引量:2
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作者 S.Richmire K.Hall M.Haghshenas 《Journal of Magnesium and Alloys》 SCIE EI CAS 2018年第3期215-228,共14页
Identification of process parameters,their effects and contributions to the outcomes of the system using experimental approach could be a daunting,time consuming,and costly course.Using proper statistical methods,i.e.... Identification of process parameters,their effects and contributions to the outcomes of the system using experimental approach could be a daunting,time consuming,and costly course.Using proper statistical methods,i.e.,Taguchi method,could significantly reduce the number of required experiments and statistical significance of the parameter can be identified.Friction stir welding is one of those welding techniques with many parameters which have different effects on the quality of the welds.In friction stir welding the tool rotational speed(RPM)and transverse speed(mm/min)influence the strength(i.e.,hardness distribution)of the stirred zone.In this study,these two factors are investigated to determine the effect they will have on the hardness in the stirred zone of the friction stir welds and how the two factors are related to one another for as-cast magnesium alloy AM60 with nominal chemical composition of Mg-(5.5-6.5)Al-(0.24-0.6)Mn-0.22Zn-0.1Si.Experimental data was taken at three different tool rotational speeds and three different transverse speeds.The data obtained was then analyzed using a 32 factorial design to find the contribution of these parameters.It was determined that both tool rotational speed and transverse speed possess significant effects on the stir zone hardness.Also,the interactions between the two factors were statistically assessed. 展开更多
关键词 AM60 Mg alloy design of experiment(doe) Statistical method Friction stir welding
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基于DOE的电机多目标多变量快速参数化设计分析
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作者 杨伟涛 《微特电机》 2023年第12期40-44,共5页
以一台9槽6极洗碗机用水泵电机为例,选取了绕组匝数、铁心高度、槽口大小、气隙直径、气隙大小、定子齿宽、定子齿高为变量,以交直轴电感、反电动势为优化目标,通过基于DOE的多目标多变量的电机快速参数化设计优化方法,实现了通过部分... 以一台9槽6极洗碗机用水泵电机为例,选取了绕组匝数、铁心高度、槽口大小、气隙直径、气隙大小、定子齿宽、定子齿高为变量,以交直轴电感、反电动势为优化目标,通过基于DOE的多目标多变量的电机快速参数化设计优化方法,实现了通过部分析因实验设计完成了常规参数化扫描最少2 187个节点的设计目标,大大节约了项目资源,提高了设计人员的设计效率,缩短了项目的交付周期。给出了各变量与优化目标间的定量关系,提高了设计人员对产品的理解以及经验设计和理论设计的水平。 展开更多
关键词 实验设计 参数化扫描 多目标优化 洗碗机用水泵电机
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基于机-电-磁-流整体耦合的油阻尼断路器保护特性的容差设计
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作者 乔延华 苏秀苹 李建娜 《现代电子技术》 北大核心 2024年第12期122-128,共7页
油阻尼断路器的主要特点是在电路发生短路、过载等情况时能够自动脱扣,断开电路,从而保护人员和设备的安全,常用于变电站等场所。文章在以往对油阻尼断路器油阻尼力、电磁铁静态特性、操作机构性能等研究的基础上,构建一个基于机-电-磁... 油阻尼断路器的主要特点是在电路发生短路、过载等情况时能够自动脱扣,断开电路,从而保护人员和设备的安全,常用于变电站等场所。文章在以往对油阻尼断路器油阻尼力、电磁铁静态特性、操作机构性能等研究的基础上,构建一个基于机-电-磁-流多体多自由度多场耦合的一体化虚拟样机整体耦合模型;接着对该整体耦合模型的保护特性进行了仿真与分析,通过仿真得到了不同电流倍数下动触头的分断特性,并通过实验验证了整体耦合模型和仿真结果的正确性;最后,为减小产品保护特性的分散程度,提高油阻尼断路器的稳定性,文中结合稳健容差设计技术,选取不同电流倍数下触头的断开时间作为目标函数,以极靴半径、细铁芯半径、粗铁芯半径、粗铁芯高度作为关键设计参数,通过正交试验和贡献率分析法对目标函数进行容差分配,使得触头断开时间的分散度比原来减少39.165%。研究成果将会对电器产品的研发提供理论指导。 展开更多
关键词 油阻尼断路器 保护特性 容差设计 多场耦合 正交试验 贡献率
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正交实验法在水性木器清漆助剂选择中的应用
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作者 姜佳丽 冯才敏 +3 位作者 卢锦莲 邢诗绵 罗逸珊 练翠霞 《广州化工》 CAS 2024年第11期100-105,共6页
水性木器清漆的配方设计主要包括原材料选择及各组分比例确定两方面内容,如采用全面实验,则实验数目多、实验时间长、效率低。本论文基于探索性初配方进行助剂的正交实验,考察润湿剂、分散剂、消泡剂、成膜助剂和增稠剂的最佳种类搭配,... 水性木器清漆的配方设计主要包括原材料选择及各组分比例确定两方面内容,如采用全面实验,则实验数目多、实验时间长、效率低。本论文基于探索性初配方进行助剂的正交实验,考察润湿剂、分散剂、消泡剂、成膜助剂和增稠剂的最佳种类搭配,然后采用正交实验考察上述助剂最佳用量搭配。通过实验数据分析,结合漆膜表观、光泽度和对比率等性能,获得漆膜无弊病、透明度较高的水性木器清漆配方。 展开更多
关键词 正交实验 水性木器漆 涂料配方设计
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火麻仁黄嘌呤氧化酶抑制肽的酶解制备工艺研究
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作者 魏连会 董艳 +6 位作者 姬妍茹 石杰 李国巍 张正海 杨庆丽 高媛 潘静 《农产品加工》 2024年第7期33-35,43,共4页
为寻找开发火麻仁蛋白,提高火麻应用价值的最佳条件,以火麻蛋白为原料,通过酶解法制备火麻仁黄嘌呤氧化酶抑制肽,采用正交试验法优化中性蛋白酶酶解火麻蛋白制备多肽的最佳工艺条件。以中性蛋白酶用量、酶解时间、酶解温度进行单因素试... 为寻找开发火麻仁蛋白,提高火麻应用价值的最佳条件,以火麻蛋白为原料,通过酶解法制备火麻仁黄嘌呤氧化酶抑制肽,采用正交试验法优化中性蛋白酶酶解火麻蛋白制备多肽的最佳工艺条件。以中性蛋白酶用量、酶解时间、酶解温度进行单因素试验,通过正交试验分析获得制备火麻仁黄嘌呤氧化酶抑制肽的最佳酶解条件为pH值6.5,料液比1∶5,酶用量6000 U/g,酶解温度50℃,酶解时间5 h。在此条件下进行的验证试验中,多肽抑制率为78.98%,表明该工艺稳定、可行,具有较高的应用价值。 展开更多
关键词 火麻蛋白 酶解 多肽 单因素试验 正交设计
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Construction of column-orthogonal designs for computer experiments 被引量:2
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作者 SUN FaSheng PANG Fang LIU MinQian 《Science China Mathematics》 SCIE 2011年第12期2683-2692,共10页
Latin hypercube design and uniform design are two kinds of most popular space-filling designs for computer experiments. The fact that the run size equals the number of factor levels in a Latin hypercube design makes i... Latin hypercube design and uniform design are two kinds of most popular space-filling designs for computer experiments. The fact that the run size equals the number of factor levels in a Latin hypercube design makes it difficult to be orthogonal. While for a uniform design, it usually has good space-filling properties, but does not necessarily have small or zero correlations between factors. In this paper, we construct a class of column-orthogonal and nearly column-orthogonal designs for computer experiments by rotating groups of factors of orthogonal arrays, which supplement the designs for computer experiments in terms of various run sizes and numbers of factor levels and are flexible in accommodating various combinations of factors with different numbers of levels. The resulting column-orthogonal designs not only have uniformly spaced levels for each factor but also have uncorrelated estimates of the linear effects in first order models. Further, they are 3-orthogonal if the corresponding orthogonal arrays have strength equal to or greater than three. Along with a large factor-to-run ratio, these newly constructed designs are economical and suitable for screening factors for physical experiments. 展开更多
关键词 computer experiment Latin hypercube design orthogonal array ROTATION uniform design
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纯电动环卫车电池托架的轻量化设计 被引量:1
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作者 杨布尧 陈江义 +1 位作者 王婷婷 秦东晨 《重庆理工大学学报(自然科学)》 CAS 北大核心 2024年第4期290-294,共5页
轻量化是提升纯电动环卫车续航里程及工作时间的重要方式,其中电池托架是承载电池模组的重要结构部件。为探究更有效的构件布置方式,建立电池托架的有限元模型,并使用拓扑优化方法得到改进结构,使电池托架在各工况下的位移和应力显著下... 轻量化是提升纯电动环卫车续航里程及工作时间的重要方式,其中电池托架是承载电池模组的重要结构部件。为探究更有效的构件布置方式,建立电池托架的有限元模型,并使用拓扑优化方法得到改进结构,使电池托架在各工况下的位移和应力显著下降。为进一步减轻质量,采用Hammersley试验方法对模型中各构件的壁厚进行采样;基于采样数据,使用2种策略的自适应响应面法对主要构件进行尺寸优化,在满足应力及位移的许用要求下,得到优化设计方案,质量减轻40%,实现了轻量化目标。 展开更多
关键词 纯电动环卫车 电池托架 轻量化设计 有限元分析 试验设计
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排气道压力波动对发动机二冲程减压制动性能的影响 被引量:1
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作者 欧阳裕茹 倪计民 +6 位作者 刘勇 黄荣 乔瀚平 尹升 石秀勇 欧成 唐田 《内燃机工程》 CAS CSCD 北大核心 2024年第1期78-85,共8页
为分析排气管内压力波动对发动机二冲程制动功率的影响,以某重型柴油机为研究对象,利用GT-Power建立发动机二冲程制动一维模型,通过修改排气型线开展排气道压力波动对制动性能影响的研究。结果表明:第二次减压制动(the second compressi... 为分析排气管内压力波动对发动机二冲程制动功率的影响,以某重型柴油机为研究对象,利用GT-Power建立发动机二冲程制动一维模型,通过修改排气型线开展排气道压力波动对制动性能影响的研究。结果表明:第二次减压制动(the second compression release braking,2nd CRB)相位开启时的压力波动会影响到其他气缸的排气回流,进而影响发动机的制动功率。进一步对排气管进行三维流场计算,证明了其他气缸2nd CRB相位排气门开启时的压力波传递对排气回流阶段排气回流的影响。最后通过试验设计(design of experiment,DoE),结合响应面拟合和粒子群算法对排气管几何尺寸进行优化,优化后该柴油机二冲程减压制动模式下2100 r/min工况的最大制动功率可达到395.08 kW。 展开更多
关键词 二冲程制动 减压制动 排气回流 进气道压力 排气道压力 试验设计
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精密轴承用PEEK保持架结构及注塑工艺优化 被引量:1
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作者 董胤喆 宁仲 +2 位作者 李建星 孙小波 席博伦 《轴承》 北大核心 2024年第4期36-39,47,共5页
针对原PEEK保持架兜孔无锁口,采用侧向抽芯机构进行注塑加工时外圆精度低的问题,将保持架兜孔分成内外两部分且设计为球面,注塑模具采用单分型面注塑模结构。并对注塑工艺浇口结构和浇口数量进行优化,基于正交试验得到最优工艺参数为模... 针对原PEEK保持架兜孔无锁口,采用侧向抽芯机构进行注塑加工时外圆精度低的问题,将保持架兜孔分成内外两部分且设计为球面,注塑模具采用单分型面注塑模结构。并对注塑工艺浇口结构和浇口数量进行优化,基于正交试验得到最优工艺参数为模具温度180℃、熔体温度390℃、保压时间5 s和保压压力55 MPa。实际加工表明:外径面圆度不大于0.15 mm占86%;拉伸强度远高于65 MPa;200℃高温摩擦系数平均值为0.195,磨痕宽度平均值为0.9625 mm,磨损量平均值为0.1394 mm^(3);与相应公差等级套圈、球合套后,轴承旋转精度达到P4,振动值达到Z4。 展开更多
关键词 滚动轴承 深沟球轴承 保持架 工程塑料 注塑 翘曲 正交试验 模具设计
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富水混合花岗岩地层地铁隧道施工中地面注浆止水帷幕的设计参数优化 被引量:1
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作者 刘健美 刘旭 +4 位作者 徐加兵 张聪 魏井申 王树英 蔡根森 《城市轨道交通研究》 北大核心 2024年第6期105-110,共6页
[目的]富水混合花岗岩地层新建隧道施工受地下水的影响显著,通常采用地面预注浆形成止水帷幕的措施来降低地下水对隧道施工过程的影响。但止水帷幕设计参数的选择大多以经验为主,可能存在隔水效果不佳、水位降低显著导致地层沉降超限,... [目的]富水混合花岗岩地层新建隧道施工受地下水的影响显著,通常采用地面预注浆形成止水帷幕的措施来降低地下水对隧道施工过程的影响。但止水帷幕设计参数的选择大多以经验为主,可能存在隔水效果不佳、水位降低显著导致地层沉降超限,以及隧道周围突涌水等现象,故需要对富水混合花岗岩地层注浆帷幕设计参数进行优化。[方法]依托广州地铁18号线番禺广场站—南村万博站区间工程,基于正交试验设计,通过数值模拟分析了止水帷幕设计参数(帷幕深度、帷幕厚度、帷幕渗透系数及帷幕与隧道间距离)对注浆隔水效果的影响;采用SPSS软件进行多元线性回归分析,拟合了选取止水帷幕设计参数的经验公式,获取了止水帷幕最优设计参数并进行工程应用。[结果及结论]止水帷幕的影响因素按影响程度排序依次为:帷幕渗透系数、帷幕深度、帷幕厚度、帷幕与隧道间距离;现场选取的止水帷幕设计最优参数中,帷幕深度为58 m、帷幕厚度为2.0 m、帷幕渗透系数为1×10-10m/s、帷幕与隧道间距离为0.5 m。现场工程实践表明,采用最优参数后,止水帷幕降低地下水位效果较好,隧道开挖时的围岩稳定且开挖面干燥,地下水对隧道开挖的影响得以有效降低。 展开更多
关键词 地铁 隧道施工 止水帷幕 正交试验 设计参数
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基于变截面积流道的液力变矩器叶栅系统设计
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作者 柯志芳 刘城 +2 位作者 郭猛 魏巍 闫清东 《北京理工大学学报》 EI CAS CSCD 北大核心 2024年第5期512-520,共9页
流道截流面积分布对液力旋转机械的液力性能具有重要影响.为了减少扩散等液力损失,变矩器流道截面积分布通常采用等截面积分布的形式,但并未充分发挥截面积分布参数在流场调节和性能优化方面的优势.因此,文中研究提出了过流截面积表征模... 流道截流面积分布对液力旋转机械的液力性能具有重要影响.为了减少扩散等液力损失,变矩器流道截面积分布通常采用等截面积分布的形式,但并未充分发挥截面积分布参数在流场调节和性能优化方面的优势.因此,文中研究提出了过流截面积表征模型,并建立了基于可变截面积分布的变矩器循环圆及叶栅设计系统,对变截面积流道的液力变矩器循环圆设计方法进行了研究.通过设计多组不同截面积分布的实例,采用DOE方法进行比较分析,进一步研究了叶轮截面积分布形式对变矩器性能的影响.同时,通过对不同叶轮的组合设计,获得了组合型性能优化的循环圆设计结果.实验结果表明,基于变截面积流道优化设计的变矩器泵轮转矩提升了18.5%,起动变矩比也提高了3.9%.说明基于变截面积分布的液力变矩器循环圆设计方法是一种有效的优化设计方法,能够在保持外形尺寸的同时提升变矩器性能. 展开更多
关键词 流体力学 液力变矩器 截面积分布 实验设计(doe) 叶栅系统
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