Transient Analysis and Leakage Detection Algorithm using GA and HS algorithm for a Pipeline System

The impact of leakage was incorporated into the transfer functions of the complex head and discharge. The impedance transfer functions for the various leaking pipeline systems were also derived. Hydraulic transients could be efficiently analyzed by the developed method. The simulation of normalized pressure variation using the method of characteristics and the impulse response method shows good agreement to the condition of turbulent flow. The leak calibration could be performed by incorporation of the impulse response method with Genetic Algorithm (GA) and Harmony Search (HS). The objective functions for the leakage detection can be made using the pressure-head response at the valve, or the pressure-head or the flow response at a certain point of the pipeline located upstream from the valve. The proposed method is not constrained by the Courant number to control the numerical dissipation of the method of charac teristics. The limitations associated with the discreteness of the pipeline system in the inverse transient analysis can be neglected in the proposed method.     

Reliability Design for Impact Vibration of Hydraulic Pressure Pipeline Systems

The research of reliability design for impact vibration of hydraulic pressure pipeline systems is still in the primary stage,and the research of quantitative reliability of hydraulic components and system is still incomplete.On the condition of having obtained the numerical characteristics of basic random parameters,several techniques and methods including the probability statistical theory,hydraulic technique and stochastic perturbation method are employed to carry out the reliability design for impact vibration of the hydraulic pressure system.Considering the instantaneous pressure pulse of hydraulic impact in pipeline,the reliability analysis model of hydraulic pipeline system is established,and the reliability-based optimization design method is presented.The proposed method can reflect the inherent reliability of hydraulic pipe system exactly,and the desired result is obtained.The reliability design of hydraulic pipeline system is achieved by computer programs and the reliability design information of hydraulic pipeline system is obtained.This research proposes a reliability design method,which can solve the problem of the reliability-based optimization design for the hydraulic pressure system with impact vibration practically and effectively,and enhance the quantitative research on the reliability design of hydraulic pipeline system.The proposed method has generality for the reliability optimization design of hydraulic pipeline system.     

A portable air jet actuator device for mechanical system identification

System identification of limb mechanics can help diagnose ailments and can aid in the optimization of robotic limb control parameters and designs. An interesting fluid phenomenon--the Coanda? effect--is utilized in a portable actuator to provide a stochastic binary force disturbance to a limb system. The design of the actuator is approached with the goal of creating a portable device which could be deployed on human or robotic limbs for in situ mechanical system identification. The viability of the device is demonstrated by identifying the parameters of an underdamped elastic beam system with fixed inertia and stiffness and variable damping. The nonparametric compliance impulse response yielded from the system identification is modeled as a second-order system and the resultant parameters are found to be in excellent agreement with those found using more traditional system identification techniques. The current design could be further miniaturized and developed as a portable, wireless, unrestrained mechanical system identification instrument for less intrusive and more widespread use.     

列车水箱防溢器的研制与应用

实用新型列车水箱防溢器,是地面上水连接器和列车水箱管路之间的装置,包括活塞套筒和弹簧,其特点是与活塞套筒内周相应地保持间隙的双向活塞组件,其端面径向外环延伸;与筒体内壁隔绝的径向孔以及位于活塞套筒和列车水箱管路的连接.有效地进行流体防溢,而且结构简单,制造容易.     

通用型液压马达实验台的分析与设计

通用型液压马达实验台的检测实验装置能够模拟实际工况对不同类型、多种规格的液压马达进行性能测试。设计一种通用型液压马达,包括实验台的连接支架设计、转速扭矩仪选型、负载系统设计、油箱设计及油路优化,并对设计参数进行了计算与有限元验证。该实验台可按照国家标准和检测方法,对多种类型不同型号液压马达做性能测试。     

天然气压缩机管道喘振治理探讨

依据现场实测数据和国家标准GB10070-1988《城市区域环境振动标准》,明确因管道喘振引起的环境振动治理必要性。从振动源天然气压缩机本体分析管道喘振原因,介绍相应治理方法,并提出一种可有效治理管道喘振的系统解决方案,为类似增压站环境振动治理提供参考。     

高铁平台卫通天线罩结构设计与仿真优化

为了实现高铁平台卫通天线易共形要求,同时满足高运行速度载荷和安装工况需求,文中采用自顶向下设计思路完成超低轮廓天线罩结构设计。在保证天线罩实现大入射角和高透波性能的前提下,首先考虑具备良好气动性能的工业设计方案,并对天线罩的结构强度、刚性和气动外形进行详细设计;同时对承载部件底罩进行静力学、谐响应仿真分析和优化,保证底罩满足一体化天线传动系统安装精度要求;最后完成罩体在高动态下的流固耦合仿真分析与优化。结论表明天线罩可满足电性能、机械性能和载车平台要求。     

航空液压管路支架参数灵敏度分析及优化

为解决航空液压系统高速高压化发展带来的航空液压管路振动加剧问题,将液压管路与管路支架视为整体振动系统。基于灵敏度分析方法,采用ANSYS软件平台中的灵敏度分析工具,分析航空液压管路支架参数对振动响应的灵敏度;在灵敏度分析结果基础上,采用基于Pareto最优的多目标遗传算法对管路支架参数进行优化设计,得到振动控制效果更好的管路支架布局,形成一种有效的航空液压管路被动振动控制参数优化方法。为控制航空液压管路振动、推动国产大飞机发展提供理论和技术基础。     

Multi-parameter Sensitivity Analysis and Application Research in the Robust Optimization Design for Complex Nonlinear System

The current research of complex nonlinear system robust optimization mainly focuses on the features of design parameters, such as probability density functions, boundary conditions, etc. After parameters study, high-dimensional curve or robust control design is used to find an accurate robust solution. However, there may exist complex interaction between parameters and practical engineering system. With the increase of the number of parameters, it is getting hard to determine high-dimensional curves and robust control methods, thus it’s difficult to get the robust design solutions. In this paper, a method of global sensitivity analysis based on divided variables in groups is proposed. By making relevant variables in one group and keeping each other independent among sets of variables, global sensitivity analysis is conducted in grouped variables and the importance of parameters is evaluated by calculating the contribution value of each parameter to the total variance of system response. By ranking the importance of input parameters, relatively important parameters are chosen to conduct robust design analysis of the system. By applying this method to the robust optimization design of a real complex nonlinear system-a vehicle occupant restraint system with multi-parameter, good solution is gained and the response variance of the objective function is reduced to 0.01, which indicates that the robustness of the occupant restraint system is improved in a great degree and the method is effective and valuable for the robust design of complex nonlinear system. This research proposes a new method which can be used to obtain solutions for complex nonlinear system robust design.     

普洱茶发酵罐的力学性能研究

发酵罐罐体工作时的变形量,应力分布,强度等直接影响到发酵罐能否安全有效的工作.本文主要运用有限元分析方法,建立发酵罐罐体模型,得出发酵罐的应力分布和位移分布,确定发酵罐的危险区域,对罐体的整体和局部受力条件有更直观准确的认识,为以后设计普洱茶发酵罐提供理论依据,并为发酵罐的进一步结构优化提供理论基础,从而提高设计的安全、经济性.     

Optimization of aero-engine pipeline for avoiding vibration based on length adjustment of straight-line segment

In the design and troubleshooting of aero-engine pipeline, the vibration reduction of the pipeline system is often achieved by adjusting the hoop layout, provided that the shape of pipeline remains unchanged. However, in reality, the pipeline system with the best antivibration performance may be obtained only by adjusting the pipeline shape. In this paper, a typical spatial pipeline is taken as the research object, the length of straight-line segment is taken as the design variable, and an innovative optimization method of avoiding vibration of aero-engine pipeline is proposed. The relationship between straight-line segment length and parameters that determine the geometric characteristics of the pipeline, such as the position of key reference points, bending angle, and hoop position, are derived in detail. Based on this, the parametric finite element model of the pipeline system is established. Taking the maximum first-order natural frequency of pipeline as the optimization objective and introducing process constraints and vibration avoidance constraints, the optimization model of the pipeline system is established. The genetic algorithm and the golden section algorithm are selected to solve the optimization model, and the relevant solution procedure is described in detail. Finally, two kinds of pipelines with different total lengths are selected to carry out a case study. Based on the analysis of the influence of straight-line segment length on the vibration characteristics of the pipeline system, the optimization methods developed in this paper are demonstrated. Results show that the developed optimization method can obtain the optimal single value or interval of the straight-line segment length while avoiding the excitation frequency. In addition, the optimization efficiency of the golden section algorithm is remarkably higher than that of the genetic algorithm for length optimization of a single straight-line segment.     

AMESim在带式输送机停机过程设计中的应用

利用AMESim软件建立带式输送机仿真模型,通过仿真分析带式输送机停机时头部和尾部重要参数在不同工况的变化情况,并利用AMESim仿真软件图形化的开发环境来优化设计参数,有利于提高设计效率。仿真过程和理论结果基本一致,取得良好的效果,说明利用AMESim仿真能为输送机制动过程的分析和控制以及输送机系统的优化设计提供一种新的分析手段和设计方法。     

污水罐在线清洗车转向系统设计与研究

设计了一种污水罐在线清洗车,重点对新型污水罐在线清洗车转向系统进行优化设计。根据Ackerman转向原理,将清洗车转向系统的实际转角关系无限趋近于理论转角关系作为优化目标,运用最小二乘法对转向梯形机构进行优化,得到了整体最优解,以此作为转向系统梯形机构的初始参数,依据现场工况对转向系统重要零部件进行设计计算,建立各主要零部件的几何模型,并进行运动仿真。内外侧车轮转角曲线与理论曲线较为接近。车轮的极限转角远远大于普通车辆的极限转角,从而能够满足清洗车转向系统较高的机动性的设计要求。     

Performance optimization of hypervelocity launcher system using experimental data

This study presents the performance optimization of hypervelocity launcher system by using the experimentall data. During the optimization, the RSM (Response Surface Method) is adopted to find the operating parameters that could maximize the projectile speed. To construct a reliable response surface model, 3 full factorial method is used with the selected design variables, such as piston mass and 2 driver fill pressure. Nine test data could successfully construct the reasonable response surface, which used to yield the optimal operational conditions of the system using the genetic algorithm. The optimization results are confirmed by the experimental test with a good accuracy. Thus, the optimization can improve the performance of the facility.     

水下干式高压焊接试验系统研究

研制了一种水下高压焊接试验装置。水下高压焊接试验装置由配气储罐、高压试验舱、气体环境检验舱、监控系统等部分组成，控制系统选用PLC，采用PROFIBUS协议，通过WINCC软件实现系统的监控和试验参数的显示、存储、记录。试验结果表明，高压焊接试验装置性能可靠，功能齐全，操作方便，控制与监控功能达到高压焊接试验的设计要求。     

往复压缩机气量调节控制失稳自愈调控方法研究

针对往复压缩机无级气量调节常见的调控失稳故障，构建包含压缩机、管道、缓冲罐、执行机构等部件的无级气量调节多系统耦合控制模型，仿真往复压缩机无级气量调节动态特性。以控制系统输出的脉宽调制控制信号作为输入，以压缩机各级排气压力作为输出，研究执行机构动态响应和控制系统调控参数对气量调节结果影响的规律；进一步针对执行机构性能参数变化导致气量调节控制失稳的问题，利用BP神经网络构建多参数负荷动态反馈模型实现调控失稳故障诊断和故障类型识别。基于故障异常类型识别结果提出一种调控参数自适应优化补偿的自愈调控方法。试验结果表明，提出的自愈调控方法可在失稳故障发生后主动施加调控参数补偿量，使得气量调节系统恢复到正常状态，实现故障在线自愈。     

船用水泥罐充压管路智能化设计

船用水泥罐充压系统能使散装物料保持絮状流动,为准确计量物料提供方便条件。对船用散装水泥罐充压系统管路结构改进设计,将充压管路进行树状分布,通过远程传感器对气室内的压力分布情况进行实时监测和调整,使絮状物料始终保持均匀流动状态,提高水泥罐的计量精确性。     

超超临界储水罐调节阀及管配系统汽蚀特性分析

针对合川电站超超临界锅炉储水罐调节阀出现的严重汽蚀现象,基于两相空化流动方程和FLUENT流场数值模拟方法,对该调节阀及其管配系统的流场特性进行分析。将模拟结果与实际失效结果相比较并提出优化方案。结果表明:基于FLUENT的空化模型模拟结果与实际工程失效情况比较吻合,加长出口管道至4m后,在三通底板处速度降低71.4%,含汽量降低84.9%。该分析方法对储水罐调节阀设计有较好的指导作用,对促进其国产化进程也有积极意义。     

基于虚拟样机技术的加油车设计

根据虚拟样机设计技术特点,详细分析了加油车管路系统零部件的结构特征和设计信息组成规律,阐述了加油车的虚拟设计结构系统,以及虚拟设计系统涉及的关键技术和应用软件的开发方法;对加油车管路系统关键零部件进行了三维建模、管路系统虚拟装配、车载油罐性能仿真分析,为虚拟设计技术在油料设备的应用打下基础.     

并联机构敏感性分析和多目标优化设计方法

为了解决并联机构全局性能指标高计算成本引起的敏感性分析和多目标优化设计困难,提出了一种结合多项式响应面模型、基于方差的敏感性分析方法和智能优化算法的高效计算方法。首先,确定并联机构的目标函数和设计参数,增加节点密度以提高目标函数的计算精度,基于拉丁超立方体抽样方法和最小二乘多项式拟合技术建立全局目标函数与设计参数之间的响应面解析映射模型,并结合基于方差的Sobol’敏感性分析方法得到对目标函数有重要影响的设计参数。然后,结合敏感性分析结果简化设计参数并建立并联机构的多目标优化设计模型,包括目标函数、约束函数和设计参数,结合响应面模型与智能优化算法开展并联机构多目标优化设计。最后,考虑规则工作空间体积、运动学性能和动力学性能指标为目标函数,以DELTA并联机构为例实现了本文提出的方法。优化前后的结果对比证明了算法的有效性。