混入气液泵油液后的危害分析和消除措施

阐述气体进入气液泵油液的途径和危害,分析计算混入气体后油液体积的弹性模量,给出油液混气量的推算方法,介绍了在设计、使用过程中减少气体混入量的措施。     

水环泵气量测定方法研究及工程应用

本文研究了水环泵对于干空气和饱和空气气量测定方法,探讨水环泵工作过程中对性能影响的温度、湿度等因素,并给出理论计算方法。介绍了湿空气实验室和饱和空气发生器工作原理,提出了特定条件下水环泵对干空气和饱和空气抽除能力的计算方法。通过水环泵性能测试实践与理论数据比较,分析了工程实践中水环泵应用常见的工况对工作效能的影响。水环泵系统可以通过改变抽除气体温度、液环温度等边界条件和增加喷淋措施,增加水环泵对饱和气体"凝化"产生的附加抽气量,提升水环泵工程适应性。     

托卡马克装置的脉冲充气问题(Ⅱ)积分方程方法

本文用解析的方法研究脉冲充气时气体分子在托卡马克装置的环形真空室内的空间过程。首先把气体分子运动化为无规行走问题,并推导出相应的积分方程。积分方程的数值解和本文第一部分的计算结果一致。在 tτ时,积分方程过渡到扩散型微分方程,这一微分方程可从稳态通导公式用唯象的方法导出。本文还对分子流的非稳态真空空间过程按其时间行为划分为以下三个区域:准稳态真空过程,扩散态真空过程,瞬态真空过程。     

快速脉冲充气阀

本文介绍快速脉冲充气阀的结构、理论、实验回路与测量方法。阀门开启时间为20微秒,注入气量可调节。实验结果与理论计算相符。     

快速真空阀门

本文介绍快速电磁真空阀门的结构、理论计算和试验。阀门开通持续时间为1～2毫秒,注入气量可以调节。控制电路使用可控硅做触发开关,并和引燃管、接触器进行了比较,阀门的理论计算和实验基本符合。     

新型碳化钙发气量测定装置的研发

介绍了一种新型碳化钙发气量测定装置,通过测量仪器装置内反应物前后质量的变化,计算出乙炔气体的质量,根据气体公式PV=nRT即可得出发气量G（L／kg）。与传统检测方法比较,该法操作简便,小巧轻便,测定准确,实现了对碳化钙发气量的快速经济检验,具有较高的实用价值。     

高效节能 回报无限——贺尔碧格HydroCOM压缩机气量无级调节系统系统

贺尔碧格集团公司的HydroCOM往复式压缩机气量无级调节系统自1995年面世以来，到目前已有近300套系统交付使用，广泛应用在化工厂．炼油厂．气体储运和联合热电厂等工业领域。HydroCOM系统以其技术的先进性和产品的成熟性占据国内外市场，在全球范围内已逐渐成为往复式压缩机气量调节系统的首选方案。     

小型活塞式膨胀机气量偏大的分析

本文通过对两台小型活塞式膨胀机气量偏大的测量,分析了造成气量偏大的三个主要原因:气体重度计算误差、忽视长活塞形成的余隙和实际转速超过设计转速。最后归结了今后设计小气量活塞式膨胀机时应注意的几个问题。图2,表1,参考文献4。     

油蒸汽流泵的抽气量和它所需的蒸汽喷射量之间关系的探讨

本文根据气体分子碰撞理论，讨论了油蒸汽流泵的蒸汽射流中起抽气作用的油蒸汽分子在流动过程中与空气分子之间的碰撞次数。求出了泵的抽气量与它所需的各喷嘴蒸汽喷射量之间的数量关系。     

分子筛吸附器再生工艺及装置

介绍一套通过原料加工气和再生气体交变流动来再生纯化的工艺及装置。在吸附器内部安装一块隔板使得靠近筒壁的吸附剂和其它区域分开,通过靠近吸附器筒壁的单位面积吸附剂的再生气体与加工气体之比,大于通过其它区域单位面积吸附剂的再生气体与加工气体之比,使得吸附器再生彻底。另外,二次排气和充气,与调节再生气量用的隔板面积有关。图3。     

Mathematical modeling of a cylinder with a sorbent and natural gas

A cylinder for adsorption storage of natural gas is modeled. A system of differential equations describing the dynamics of nonequilibrium sorption is formulated. The process of withdrawal of gas from the cylinder is numerically analyzed.     

Piezoelectric Behavior of an Inhomogeneous Hollow Cylinder with Thermal Gradient

An analytical solution to the axisymmetric problem of a radially polarized, radially orthotropic piezoelectric hollow cylinder with a thermal gradient and subjected to various boundary conditions is developed. The elastic coefficients, piezoelectric coefficients, stress-temperature moduli, dielectric coefficient, pyroelectric coefficients, thermal conductivity coefficient, and thermal expansion coefficients of the hollow cylinder are assumed to be graded in the radial direction according to a simple power-law distribution. The governing second-order differential equations are derived from the equilibrium equation, the charge equation of electrostatics, and steady state heat transfer equation through the radial direction of the inhomogeneous hollow cylinder. The displacement, stresses, and potential field distributions in the cylinder are examined. The influence of the inhomogeneity parameter on the numerical results is investigated.     

Continuous accretion of a composite cylinder

Summary A new model is derived for winding of a composite thick-walled cylinder with finite strains. Continuous growth of a cylinder is treated as a limit of successive accretion of built-up portions (thin-walled shells) consisting of a fiber bundles and resin. Due to preload of fibers, a gradient of pressure arises in the cylinder which causes resin flow. Nonlinear partial differential equations are developed which permit stresses and displacements in a wound cylinder to be determined with account for the material accretion and resin flow. At infinitesimal strains, these equations are reduced to a linear Volterra integral equation for pressure on mandrel. This equation is solved numerically to analyze the effect of material and structural parameters on stresses in a wound cylinder.     

The influence of thermal relaxation and thermal damping on transient processes with cyclic boundary conditions

Variants of the differential equation of heat conduction in a solid body, which follow from the Fourier and Cattaneo–Vernotte hypotheses and the Lykov equation, are considered. A boundary value problem describing temperature fields in a body (cylinder) upon cyclic heat transfer with cold and hot media is formulated. An analytical solution to the boundary value problem with a hyperbolic differential equation of heat conduction with allowance for thermal relaxation and temperature damping with cyclic boundary conditions of the third kind is given. The thermal transient processes calculated by the classical heat conductance equation and hyperbolic equation of heat conduction on the axis of the cylinder at different values of factors such as the ratio of the thermal damping time to the thermal relaxation time, the duration of cyclic periods, the Fourier relaxation number, and the Biot number are compared. A conclusion is made that the theory of regenerative air heater should be improved by taking into account thermal relaxation and thermal damping in the nozzle and measurements of the thermal relaxation and thermal damping times of the corresponding materials.     

T700碳纤维增强树脂复合材料气瓶封头非测地线缠绕强度

利用微分几何理论和四阶龙格库塔法求解气瓶封头上T700碳纤维增强树脂复合材料（CFRP）非测地线缠绕角微分方程,得到稳定的非测地线缠绕轨迹;利用有限元仿真软件建立T700 CFRP缠绕气瓶有限元模型,分析不同非测地线轨迹对工作压力（30 MPa）下T700 CFRP缠绕气瓶强度的影响,并采用渐进损伤模型分析爆破压力的变化规律。对于封头高h=50 mm的T700 CFRP缠绕气瓶,滑线系数为0.2时承载能力最强,比T700 CFRP测地线缠绕气瓶提高了7 MPa,约为6.4%;对于封头高h=160 mm的T700 CFRP气瓶,滑线系数为0.2时承载能力最强,比T700 CFRP测地线缠绕气瓶提高了6 MPa,约为11.5%。结果表明,优化设计得到的缠绕线型既能满足缠绕工艺的基本要求,又提高了T700 CFRP缠绕气瓶的结构力学性能,可为实际缠绕工艺提供参考。      

The elastic rotating cylinder

A fully relativistic formulation is presented for an infinitely long, elastic cylinder of constant density, rotating uniformly about its axis. The problem is reduced to a non-linear differential equation in the displacement which is linearised to obtain classical and special relativistic solutions. These are compared with a typical general relativistic numerical solution.     

Mathematical analysis of thermoelastic characteristics in plasma-sprayed thermal barrier coatings

The thermoelastic characteristics of plasma-sprayed thermal barrier coatings (TBCs) have been analyzed using mathematical modeling. Two types of TBC model, cylinder and circular disk which are commercial plasma-sprayed TBCs, subjecting to symmetric temperature distribution to the radial and longitudinal directions, respectively, were taken into consideration. Based on the thermoelastic theories, a second order ordinary differential equation was derived for the cylinder model and a pair of partial differential equations were set up for the circular disk model. The analytic solution was obtained from the ordinary differential equation, while a finite volume method was developed for numerical solutions to the pair of partial differential equations due to the complexity of governing equations. The thermoelastic characteristics of TBC models, such as temperature distributions, displacements, and stresses, were displayed according to the obtained solutions. The rate of heat conduction in the section of the top coat is relatively slow in comparison with the substrate, and no profound difference appears in the temperature distribution between two TBC models. The highest longitudinal tensile stress is expressed at the bond coat of both models, and the substrate is under the compressive stresses to the circumferential direction. While the cylinder expands to the positive longitudinal direction only, the expansion in the circular disk occurs to both the positive and negative longitudinal directions. Relatively large displacement and stresses exhibit in the cylinder as compared with the circular disk. In the circular disk, the stresses to the radial direction undulate at each section, and the displacement profile displays that the width of the circular disk is slightly narrowed. The results demonstrate that the mechanical and thermal properties of the top and bond coats are the crucial factors to be considered in controlling the thermoelastic characteristics of plasma-sprayed TBCs.     

柱塞式校准器检定临界流喷嘴的实验研究

介绍了一种采用标准柱塞结构的临界流喷嘴校准器的原理和组成.根据临界流喷嘴的流量特性建立了检定数学模型,同时建立工作腔气体状态方程,并进行分析.对该校准器工作腔的压力和温度进行了大量实验研究,结果表明,工作腔内气体的压力和温度在检定过程中能够保持稳定,有益于提高检定的精度和效率.利用该校准器进行临界流喷嘴背压比试验,调节被测喷嘴背压比,检测其实际流量,得到与理论曲线相一致的流量特性曲线,从而为临界流喷嘴的特性研究提供了一个良好的手段.     

基于精细传递矩阵法的变厚度圆柱壳自由振动分析

结合精细积分和传递矩阵方法,对变厚度圆柱壳的自由振动进行计算分析。该方法基于圆柱壳的基本微分方程,推导得到关于位移内力向量的一阶齐次偏微分方程,采用精细积分求得场传递矩阵,将其进行组装得到总传递方程,根据边界条件求解总传递方程中系数矩阵的行列式,计算得到变厚度圆柱壳的固有频率。将计算结果与有限元结果进行对比,验证方法的准确性及有效性。同时探究了边界条件、厚度变化形式、厚度变化系数及长径比对自由振动的影响规律。