为确保炮射制导弹药的结构及各分系统满足耐高过载要求,同时减少实验次数和缩短研制周期,对弹仓回收系统部分进行流场仿真和数据分析.弹仓在同口径回收管运动产生的空气阻力,一部分提供反向过载,另一部分在回流管内传递,使得弹仓减速并反向运动,在回收管内进行来回震荡3～4次.根据流场仿真数据结果,预充气体压力、弹仓的质量和回流管直径均影响回收过程的反向过载和回收状态,为后续软回收试验平台设计提供了理论依据.

针对可调节式的阀控式制退机,分析其结构及工作原理,建立模糊PID控制器,提出了基于粒子群算法对模糊PID控制器进行优化.分析阀控式制退机理论液压阻力曲线,基于此曲线对模糊PID控制器和粒子群算法优化的模糊PID控制器进行仿真,对比阶跃跟随曲线和ITAE性能指标.搭建模拟试验平台,使用粒子群算法优化的模糊PID控制器进行试验,分析液压阻力变化曲线.试验结果表明此次设计的控制器具有很好的控制精度和稳定性,能较好地提高系统的性能指标,研究结论可以为阀控式制退机在火炮上的使用提供参考.

为研究某新型阀控式制退机的缓冲性能,用等效运动方法,在Fluent中建立制退机内部流场模型,分析了流液孔的面积ax对液压阻力系数K值的影响,在一定范围内,随ax的减小,K值不断增大,取值范围在1.1～1.8.以模拟后坐试验平台为背景,构建了模拟后坐过程的动力学模型,采用Simulink进行动力学仿真,对比仿真与试验结果,验证了该阀控式制退机的缓冲性能和调节能力,为该制退机在火炮上应用奠定了基础.

研究了某新型阀控式火炮制退机的流场运动规律,以台架试验为背景,通过Fluent软件进行了等效流场分析,推导得出了主流流道液压阻力系数K的取值,并以某成熟的节制杆式制退机进行验证.研究了液压阻力系数K与流液孔面积ax的关系,K值在后坐过程中处于动态变化,其值为1.39～2.05,且随流液孔面积的减小而在一定范围内逐渐增大.建立了台架工况下的动力学模型,为后续制退机的台架试验.

设计了一种可调节式反后坐装置,其制退机部分的核心在于依靠电机控制内部的动活塞在后坐运动的短暂时间内按照规律转动.提出了一种利用CANopen通信协议DS301及伺服电机驱动子协议DSP402实现电机位置插值控制的方案.根据活塞转动要求对具体控制方式进行了研究分析并确定程序设计框架,基于CANopen协议进行伺服控制的原理进行了控制系统设计,监测结果表明该控制方案能够达到预期运动目标,为后续的实验和研究提供参考.

根据相似原理推导三层桨叶功率影响因素关联式,应用Fluent软件对铝熔体搅拌过程中的搅拌功率特性进行模拟分析,研究工艺参数和桨叶结构对搅拌功率的影响.分析结果表明:搅拌功率与搅拌转速的三次方成正比;搅拌功率随铝熔体温度的升高而降低,铝熔体温度升至1 073 K时搅拌功率变化趋于平缓;搅拌功率随桨叶倾角的增大而降低,倾斜角为0°时最大;此外,桨叶浸入深度和桨叶层间距对搅拌功率也有一定的影响.

In order to make full use of the color, shape, texture, and other features in the 3-D vehicle model, a 3-D vehicle model retrieval method is proposed based on angle structure features using render images as dataset. First, the 3-D vehicle model render images are taken as a testing set and the marked natural images are taken as a training set. The render images are classified based on their skeleton-associated shape context and the angle structure features are extracted to establish the feature library. Then, the angle structure features of the input natural image are extracted. The distance measure method is used to calculate the similarity between the angle structure feature of input natural image and those features in the feature library in order to achieve the 3-D vehicle model retrieval. The experimental results show that this retrieval method can effectively improve retrieval performance for the 3-D vehicle model.

为满足武器水下发射的特殊环境与特殊要求,对水下摆动模拟发射试验装置结构进行设计.对于在研的某水下摆动模拟发射试验平台,根据给定技术参数,运用3维建模软件设计了水下摆动模拟发射试验装置,对传动系统的结构进行了设计和不同运动模式计算分析,并对试验装置可能受到的各种阻力进行了分析计算.分析结果表明:该设计具有一定的实用性,满足设计要求,可为后续设计提供铺垫.

根据GJB 4225-2001的规定,要求被试榴弹包装箱在车载装卸(模拟高度3m)或装船海运(模拟高度12m)期间意外跌落安全.为了考核被试榴弹包装箱跌落是否符合安全要求,需要一种装置来模拟榴弹包装箱任意姿态下进行自由跌落的试验.作者从柔性夹持装置出发,综合设计了一套适合榴弹包装箱跌落实验的试验装置,该试验装置采用压缩弹簧预紧系统实现了在夹持过程中可靠性和安全性的保证,采用激光传感器完成了对跌落高度关键数据的测量.通过AD-AMAS和MATLAB联合仿真和场地试验,结果表明,该系统满足榴弹包装箱任意姿态跌落且得到稳定可靠的试验数据.

针对某火炮液压缓冲器在工作过程中流道结构变化的特点,在Fluent软件中建立了缓冲器的等效流场模型;根据伯努利方程,由工作腔压力推导反映液体流动过程受流道结构特征和流速影响的压力损失的液压阻力系数K,分析了流速、节流杆直径与液压阻力系数K之间的关系.将系数K动态取值的方法应用到某火炮运动机构仿真分析中,通过试验对比缓冲器活塞杆位移验证了系数K动态取值方法的合理性.

Aiming at the shortcomings such as insufficient utilization of energy of single stage cylinder pneu-matic engine,low efficiency and unstable output torque,the structure device of inline four -cylinder pneu-matic engine is proposed,and the thermodynamics and dynamic analysis of two-stage four-cylinder are car-ried out respectively. Mathematical model of cylinder working process. Based on the working characteristics of in-line four-cylinder pneumatic engine,a number of control parameters are selected to simulate and ana-lyze the influence of each factor on the system′s aerodynamic efficiency and aerodynamic power. The simu-lation results of single-stage cylinder engine are compared with each other. The results show that the in-line two-stage four-cylinder pneumatic engine has the advantages of low speed and high torque in the condition of 0.8MPa. The two-stage four-cylinder expansion work mode is improved in the output of the pneumatic en-gine Torque while ensuring a higher aerodynamic efficiency;the second stage of the cylinder than the system has no significant impact on the aerodynamic efficiency.

According to the GJB 4225-2001,the tested grenade is required to be safely dropped during loading and unloading (simulated altitude 3 m) or during shipment (simulated height 12 m).In order to assess whether the tested grenade drop is safe,a device is needed to simulate the grenade free-fall at any posture.In this study,a set of test device for grenade drop experiment is designed:the tensile spring preloading system is to guarantee the reliability and safety during gripping process;the rotary dial is to achieve multi-angle drop control;the laser sensor is to the measure the key data of the drop height.Through ADAMAS and MATLAB combined simulation and field test,the system can meet the requirments.

A device based on memory test technology is developed to measure high acceleration of gun launching for a test system.The system recycles projectile without damage.Importantly,the projectile experiences high overload inside the barrel.STM32 is the control center of this device,which can achieve signal conditioning,data storage,serial ports communication.One external trigger with multiple internal trigger is used in the software.The test phenomenon of false triggering is avoided effectively.In addition,the acceleration sensor and storage test circuits are installed separately,which is convenient to remove the sensor.This device can be installed in the tail of the projectile,which can measure and record acceleration data in the process of launching projectile.Recycling the device after the experiment,the collected data can be read by the PC and can be displayed by waveform.It will provide important experimental basis for theoretical analysis,parameter settings of non-destructive recycling projectile.

针对有限容积减压对控制元件的要求,设计了高压气动大流量电磁开关阀,并根据其结构,运用电磁学、热力学、流体机械力学原理,建立了电磁-气热-机械耦合的数学模型.通过电磁阀的数学模型进行了计算机仿真,结果表明:电磁阀在运动过程中分为四个阶段:先导阀触动、先导阀运动、主阀运动、主阀保持.通过分析各个电磁阀参数发现,对响应时间影响较大的是前三个阶段.采用遗传算法对主要的电磁阀结构参数和控制参数进行多参数优化,取得了较好的优化效果.

为了确定单级气动发动机的最优配气持续角区间,根据该气动发动机的工作原理建立了基于MATLAB/Simulink的仿真模型.在负载扭矩恒定的前提下,通过改变仿真参数,发现输出功率随着配气持续角的增大呈先增大后减小的趋势,气耗率在70°～100°区间内较低,在70°～100°区间内呈迅速增大趋势,而能量利用率的变化趋势与气耗率相反.通过对仿真结果的分析,考虑动力性能指标和经济性能指标,确定气动发动机最优配气持续角区间为80°～100°,该结论可为多级气动发动机的结构设计和控制策略的制定提供参考依据.

Hydraulic resistance coefficient k1 reflecting mainstream channel structure’s characteristic is a key parameter in artillery recoil mechanism design.It can be initialized with tests when channel structures are similar, otherwise it may be different completely.Here,a cylinder wall groove recoil mechanism was studied.For obtaining the reasonable range of k1 in theoretic design,the influencing parameters were studied.Based on the mainstream channel structure analysis and reasonable simplification,the piston rod was fixed,the recoil velocity of the recoil rod V was simulated with inlet velocity V′and the free outlet was set,the equivalent flow field model was built and simulated in Fluent.Under the certain condition of inlet velocity V′and the channel cross-section area ax,the piston force was calculated.And then,the coefficient k1 was deduced with Bernoulli equation.The presented method was validated with a mature recoil mechanism.According to this method,the influences of V and ax on k1 were studied.It was shown that the coefficient k1 increases within a range gradually with decrease in V and ax during recoil;under conditions of the recoil mechanism’s parameters here,and using the comparison between the simulated recoil force and the tested one,the reasonable range of k1 is 2.4~2.7.

In modern intelligent ammunition,terminal sensitive unit,guidance device and fuze are mainly composed of precision micro optical electro-mechanical systems,microprocessors and power units,etc.High overload test with these components is an important method to study artillery great and ammunition suitability and ballistic linkage characteristics.To stop a high speed projectile experiencing over great acceleration inside a barrel within a limited distance and without damage,the soft recovery method was studied with theoretical analysis and tests.By compressing air ahead a projectile in an identical caliber recovery tube with a single stage diaphragm rupture,the projectile’s kinetic energy was absorbed and released.The compressed air chamber was described with an one-dimension constant cross-section unsteady inviscid flow equation.And combined with the projectile dynamic equation,the mathematic model of the soft recovery system was set up.The second order MacComark scheme with an artificial viscous term and the four order Runge-Kutta method were applied to solve equations numerically.The matching relationship among projectile’s initial velocity,chamber initial pressure and diaphragm rupture pressure was analyzed.With the proposed method,test results showed that the soft recovery system can successfully catch a projectile having a mass of 36 kg,a length of 1 55 mm and the max initial velocity of 548 m/s within a distance of 42 m.

在分析传统的机械类专业生产实习组织模式存在的弊端的基础上,结合宁波市制造类企业对毕业生的需求情况,提出了一种跨暑期工作型的生产实习模式.该模式通过校企合作的方式,针对学生就业竞争能力、工程实践能力和创新素质的培养,安排学生在暑假期间以及后续时间进入合作企业,历时两到四个月时间在实际生产环境下真刀真枪地实习.文章还从学生、企业和学校三方面论述了该实习模式的优越性,并展望了该模式在机械工程类专业实践教学体系里的推广价值.

针对单级膨胀器的效率低下等缺陷,提出两级膨胀器的结构形式,并对其进行热力学和动力学分析,建立了数学模型.根据两级系统模型进行计算机仿真,结果表明:两级膨胀器在进气高压的工况下,高压气体膨胀更加充分,并符合膨胀器高扭矩、低转速的性能要求.此外,还选取若干个控制参数,研究其对气动效率和气动功率的影响.在相同的设计时速下,不同的进气行程比和传动比相匹配,系统的气动效率基本相同,且低负载率有利于提高系统效率;第二缸尺寸对系统气动效率影响不大,但对功率具有较大影响,需要选择适宜的尺寸.

It uses the spiral spring as energy storage component to design the equipment for braking energy recov-ery.This equipment can achieve the braking kinetic energy storage and release it when the vehicle starts or ac-celerates.It builds the mathematical model for braking recycling process and the release process of the equipment and simulates the relationship between its characteristic curve and characteristic curve of traditional friction brake, verifies its feasibility.It analyzes the simulation result, discusses the influence of spring and initial veloc-ity of the flywheel in the efficiency of braking energy recovery, and verifies that the method of spiral spring for braking energy recovery is efficient and feasible.