一种压力过程的模糊自适应预测控制器

煤气生产过程的压力波动，影响了煤气的正常生产。煤气的输出气量，由于受用气量负荷影响呈随机扰动特性，这使得压力过程表现出不确定性，加之压力对象本身的非线性，为保证煤气生产过程的压力稳定，较早采用的一些传统控制方法效果较差。在此给出一种有效的压力过程控制方法：针对不确定的煤气生产压力过程，通过拟合原理，用局部线性模型代替非线性模型，完成了模糊模型辨识相模糊控制的算法；同时，采用简化的算法预测系统时延，并施加自适应控制算法；成功地解决了这一类控制问题。     

一种气体炮的建模与分析

应用气体动力学理论及配合间隙的影响建立了气体炮模型,采用MATLAB语言对其进行数字仿真分析,得出气体炮不同初始容腔的体积与压强对炮弹的速度-位移的影响曲线,便于设计气体炮选择合适的储气罐容积、压强以及身管长度等.     

Numerical and experimental investigation of the metering characteristic and pressure losses of the rotary tubular spool valve

This paper presents the results of numerical and experimental performance evaluation of the rotary tubular spool valve. The aim of this work is to develop further the novel design of the tubular spool valve by confirming experimentally the validity of the simulation model and its results, thereby proving the valve's potential to represent a feasible and more efficient alternative to conventionally used translation spool valves avoiding the use of two stage valve configurations. In this research the valve performance is assessed through numerical modelling and experimental studies of its metering characteristic and pressure losses. This paper demonstrates that the used valve model yields the results, which agree well with the conducted experimental study. Therefore, validation of the numerical model and the modelling results in the form of theoretical valve characteristics was accomplished. Firstly, the paper presents details of a numerical approach employed to evaluate valve performance and then analyzes the simulation results. Next, the valve performance is experimentally validated by testing a prototype valve on a hydraulic test rig capable of measuring the volume flow rate, pressure levels in up- and downstream lines of the valve across the entire spool angular stroke. Initially, average discrepancies between modelling and test results were 52.46% for the metering and 82.78% for the pressure loss characteristics. Correcting the model geometry aimed at eliminating differences between the valve model and the practically used prototype-test rig system enabled reduction of the error between experiment and modelling by 47.75% for the pressure loss function. This confirmed validity of the simulated characteristics of the valve. The benchmark comparison of pressure losses confirmed average 71.66% energy dissipation reduction compared to the industry-available analogue valve.     

差压法检测压力气体泄漏的研究

随着科学技术的发展,各种压力容器和设备的应用越来越广泛。相应地,压力气体的泄漏检测就显得尤为重要。在对比多种气体泄漏检测方法的优劣后,选择差压法来检测气体泄漏。对差压法泄漏检测的方法、原理、模型、检测回路、检测过程和气体泄漏量的计算进行了逐一的研究。     

Modelling pressure distribution in a rectangular gas bearing using neural networks

Gas ubricated bearings are of tremendous use especially in the biomedical and aerospace industries. For that reason, gas bearings have been the subject of much research for the past decade or so. Experimental as well as theoretical work has been done to calculate the pressure distribution inside the bearing. The models available to predict the pressure are primitive and need to be improved. This paper discusses a new modelling scheme known as artificial neural networks. The pressure distribution and the load-carrying capacity are predicted using feedforward architecture of neurons. The inputs to the networks are a collection of experimental data. This data is used to train the network using the Levenberg-Marquardt optimization technique. The results of the neural network model are compared to a theoretical model and the results are promising. The neural network model outperforms the avallable theoretical model in predicting the pressure as well as the load-carrying capacity.     

轮胎刚度和阻尼非线性模型的解析研究

根据轮胎的静态和动态试验结果,建立了轮胎刚度和阻尼的非线性解析模型.该模型分析了轮胎刚度与轮胎变形量、充气压力和振动频率之间的数值解析关系;同时还分析了轮胎阻尼与振动速度、轮胎变形速度和充气压力之间的关系.     

Computer aided modelling and diaphragm design approach for high sensitivity silicon-on-insulator pressure sensors

Silicon on insulator (SOI) pressure sensor diaphragm is a composite structure of the buried oxide and the SOI layer. This paper brings out the inadequacy of the existing analytical model in describing the deflection response of SOI square diaphragms and focuses on the computer aided burst pressure incorporated high sensitivity design approach using IntelliSuite for SOI pressure sensors. The simulation results indicate that the maximum sensitivity is achieved at a side length of 800 μm for burst pressures of 10 and 5 MPa and at 900 μm for burst pressure of 2 MPa. The new modified analytical model developed and presented in this paper for describing the load–deflection performance of SOI composite diaphragm is able to predict the deflection accurately when compared with deflection obtained by IntelliSuite FEA thus illustrating the validity of the computer aided design approach. Further the new model has demonstrated that the existing analytical model overestimates the deflection and hence inadequate for application to SOI pressure sensors. The subsequent piezoresistive analysis carried out on these SOI sensors also confirms these findings and the maximum sensitivity that can be achieved is estimated to be 56 mV/MPa/V for the burst pressure of 5 MPa. The experimental results reported in the literature have been compared with the simulation results to validate the design approach presented in this paper.     

水铰链压力损失的有限元分析与测试验证

压力损失是水铰链的重要技术指标之一,文中通过建立水铰链流体通道的压力损失数值模型,应用FLUENT工具进行有限元分析,得出计算结果,并通过压力损失测试系统实测出压力损失数据。两者的比较结果验证了数值模型的准确性。该模型的建立为进一步降低水铰链流体通道的压力损失提供了数值模拟方法,对水铰链研究及改进具有指导意义。     

压力继电器的设计

建立了压力继电器的数学模型，明确了设计要点，确立了实现系列化设计的结构。     

活塞膜片式压力补偿器的分析

针对深海大压力平衡问题，提出一种活塞膜片式压力补偿器，阐述了补偿器的工作原理。采用O型圈密封结构，并通过 ANSYS 大型分析软件对其密封性能进行了分析。建立了补偿器的数学模型，利用Simulink进行了仿真，证明该补偿器能够实现深海压力和油液体积的补偿，拥有较好的密封性能和良好的动态特性。     

基于ANSYS的热声制冷机谐振管强度的验证

介绍了热声制冷机的相关内容,并设计了一种等直径谐振管。在ANSYS 12CFX中建立谐振管中空气三维模型,并施加交变的压力边界条件,对空气场受到的压力进行分析,得到其所受的最大压力。将分析得到的最大压力加载到谐振管的三维模型的内表面,进行应力分析。根据最后得到的应力云图进行计算,得出结论,证明所设计的谐振管符合强度要求。     

数字比例阀先导级输出压力调节特性研究

用高速开关阀组建数字比例阀的先导级,通过对高速开关阀的输入电流脉冲信号进行调制实现对先导级输出压力的比例控制.建立了先导级输出压力比例控制的数学模型,分析了脉冲调制方式和先导级各油路液阻对输出压力调节特性的影响,利用AMESim组建先导级的仿真模型.仿真结果可为先导级的设计提供相关参考.     

超声波非接触检测液压系统压力的辨识与仿真研究

本文介绍超声波检测液压系统压力的原理,通过辨识得到了测压的精确传递函数;利用MATLAB环境下的仿真工具SIMULINK进行了仿真研究,并通过实验数据的验证,表明了数据模型的建立及超声波检测压力的理论是正确的。     

大型矿用挖掘机风道压力损失的计算

以流体动力学为理论依据,阐述了大型矿用挖掘机风道压力损失的计算方法。以35 m3挖掘机通风除尘系统为例,建立了风道模型并计算了风道的沿程摩擦阻力及局部压力损失,同时也进一步验证了35 m3挖掘机风道设计的合理性。     

A lumped-parameter model to investigate the effect of plantar pressure on arterial blood flow in a diabetic foot

This paper presents a lumped-parameter model for the big-toe region that investigates the effect of plantar pressure on the diameter of the blood vessels, specifically the arteries, in the presence of arterial and/or tissue changes. The model developed in this paper uses a multi-domain energy system approach to develop the lumped-parameter differential equations. Blood flow is modelled as fluidic flow through compliant pipes that have inertia, stiffness, and damping. The tissue material is treated as a soft compliant material that transmits the external force to the blood vessels. Conclusions have been drawn to show the effect of plantar pressure, tissue damage, and their combination on the diameter of the blood vessels. The principles used here can be used to model the entire foot and the model used to investigate the effect of plantar pressure, tissue damage, and arterial changes on different parts of the foot. The work presented here may also have applications in other vascular diseases.     

高速列车气流组织变化对空调机组的影响分析

分析了列车提速以后,车体表面压力的变化情况和规律.采用Fluent 6.3应用SIMPLE算法对高速列车表面气流组织建立计算模型,进行了不同车速的列车表面气流组织变化的数值模拟计算和分析,得到列车表面压力随车速的变化,通过与相关文献提供的实测列车压力分布进行比较,得到模拟结果与实测结果基本一致.分析了气流组织变化对列车空调机组的影响,为分析因提速引起的空调变工况性能的影响提供了重要的技术依据。     

大型矿用载重车轮辋强度计算的建模分析

以轮辋只受胎内气压并卸去车轮隔圈的工况为例这是一较危险的工况，对轮辋的受力作了分析研究，建立了强度计算的两种解析模型－梁模型和壳模型，使轮辋的强度计算大为简化。模型的建立提供了轮辋受力分析的原则，这一原则同样适应于其他工况。本文将所建立的模型用于某百吨矿用车强度计算分析中，并用有限元法作了分析对比，证明了所提出的计算模型及分析方法的可靠性。     

新型补偿式疏水器的设计及应用

针对氧化铝生产高压溶出、蒸发器、高压蒸汽、冷凝水的特点 ,以及国产和引进的手动、气动控制阀存在的不足 ,我们研制了补偿式疏水器1) ,保证了上述生产系统的正常运行 ,取得了良好的效果。本文将从工作原理、机械设计 ,使用效果以及推广前景予以探讨     

On the effective length of the top piston ring involved in hydrodynamic lubrication

This paper describes a simple analytical model for top piston ring lubrication. The model is constructed using the open‐end boundary condition hypothesis, with an assumption of minimum hydrodynamic pressure in the effective ring length equal to the saturation pressure. The analysis confirms that not all of the ring length is involved in the case of hydrodynamic lubrication, and the effective length is found to be less than 40–50% under some operating conditions. The results are in agreement with previous investigations.     

3D FE modelling of contact pressure response in cold rotary forging

Investigating the contact pressure response in metal forming is significant for effectively predicting the die wear and controlling the metal flow of the workpiece. This paper is aimed to utilize FE methods to reveal the contact pressure response in a complicated metal forming technology of cold rotary forging. For this purpose, a 3D FE model of cold rotary forging is first developed. Then, the contact pressure is numerically calculated. Finally, the effect of the process parameters on the contact pressure response is revealed. More importantly, the relationship between the contact pressure response and metal flow of the workpiece is clarified.