高温高压气井测试管柱井筒温压耦合预测分析

测试管柱入井之前对井底温度压力的预测是非常有必要的。该文根据动量、能量守恒定律以及传质传热学相关理论,对气体与管壁之间的摩擦生热以及气液两相流的影响因素进行了综合分析,建立测试管柱井筒温压耦合预测分析模型。利用四川某气田X井的实测数据对模型进行了验证分析,并将该结果、文献模型以及WellCat模型求解的结果分别与实测数据对比,同时对不同产量、不同气体密度和不同生产时间状况下井筒的温度压力分布进行敏感性分析。结果表明该文所提出的温压耦合模型的计算结果良好,精确度较高。     

SiCl4/H2辉光放电等离子体中电子特性的在线检测

SiCl4/H2混合气体被公认为低温沉积纳米晶以及多晶硅薄膜最具潜力的气源之一.首次利用加热可调谐Langmuir探针对等离子体增强化学气相沉积系统中的SiCl4/H2放电等离子体的电子浓度和电子平均能量进行了在线检测,并分析了电子特性随系统各参数:气体压强、射频功率及氢稀释度RH的变化规律.实验结果表明:随着气体压强的升高,电子浓度不断增大而电子平均能量不断减小;增大射频功率或减小氢稀释度RH,电子浓度和电子平均能量都相应增大.此外,并对实验结果进行了定性或半定量分析.本研究工作将有助于更好地理解SiCl4/H2放电机理,改善并优化沉积优质多晶硅薄膜的工艺参数.     

射频输入功率对DLC∶F∶Si薄膜结构和附着特性的调制机理

以SiC陶瓷靶为靶材,Ar和CHF_3为源气体,采用反应磁控溅射法在双面抛光的316L不锈钢基片上制备出了系列Si和F共掺杂的DLC∶F∶Si薄膜。研究了射频输入功率对薄膜的附着力、硬度和表面接触角的影响。结果表明,选取适当的输入功率(180W左右)可以制备出附着力达11N的DLC∶F∶Si薄膜。通过拉曼和红外光谱分析以及样品粗糙度分析,作者提出了输入功率对DLC∶F∶Si薄膜结构和特性调制的机理,即输入功率直接影响SiC靶的溅射产额、空间Ar~+的能量以及CHF_3的分解程度,继而影响空间Si、C、-CF、-CF_2,特别是F~*等基团的能量和浓度,调制薄膜中F含量以及Si-C键含量和C网络的关联度。Si-C、C=C键的增加有助于薄膜附着力的明显改善,F含量的减少则会导致薄膜的疏水性能有所下降。     

射频磁控溅射法ZnO薄膜制备工艺的优化

用射频磁控溅射制备ZnO薄膜,研究了溅射功率、溅射气体中氧氩以及工作气压对薄膜结构和光学性能的影响。通过对不同制备条件下的薄膜结构和薄膜的室温透射谱的分析,得到了磁控溅射制备ZnO薄膜的最佳工艺参数。     

等离子体状态对PECVD SiC薄膜微结构的影响

在PECVD法制备SiC薄膜过程中,深入研究了工作气压及工作气体中氢稀释比例对薄膜的影响．发现以上两个参数是通过共同调整等离子体状态的两个主要参数——等离子体成分及离子能量来起作用的。在此基础上,讨论了等离子体状态在SiC薄膜微结构从非晶转化为纳米晶过程中的作用．发现可以通过控制等离子体成分及离子能量来得到可用于场发射阴极的纳米晶SiC薄膜。     

脉冲激光沉积中高能量密度激光密度对Cu_2Se热电薄膜成分与性能的影响（英文）

本工作提出了脉冲激光沉积法生长Cu2Se热电材料薄膜中维持较高的激光切削能量密度对于实现薄膜与靶材成分等比例传输的重要性。使用较高的脉冲激光能量生长的Cu2Se薄膜具有纯的?-相,并具有与靶材相近的化学组分。这主要是因为较高的激光能量可以更加有效地引起等离子体对激光-固体直接作用的屏蔽,这可以使得靶材中的铜和硒元素的激光切削量更加接近靶材的化学计量比。由于硒具有较高的蒸汽压,降低激光能量会加强激光与固体的直接作用,从而更有效地切削硒元素,导致所沉积薄膜中产生铜缺陷。进一步讨论了所使用的氩气背景气体压力对于所生长的Cu2Se薄膜热电性能的影响。当使用高激光能量低背景气体压力时,所生长的薄膜具有最佳的热电性能。     

偏压对反应磁控溅射TiN薄膜结构以及性能的影响

本文采用直流反应磁控溅射技术,以Ar和N2为反应前驱气体制备了TiN功能装饰薄膜.重点研究了衬底负偏压对沉积TiN薄膜的色泽、性能及微结构的影响.采用台阶轮廓仪、X射线衍射仪、EDS能谱仪、纳米压痕仪等分析了薄膜的粗糙度、晶相、组分、纳米硬度以及弹性模量.结果表明,采用适宜的衬底负偏压调控轰击离子能量,能够有效阻止薄膜结构中空位以及缺陷的产生,从而有效避免薄膜表面的紫黑色氧化钛的生成,有利于表面光滑的金黄色TiN薄膜制备,同时使薄膜具备更优异的力学性能.实验结果还表明基体偏压可显著影响TiN薄膜的择优生长取向:随偏压增加,薄膜由(111)晶相择优生长转变为(200)晶相的择优生长,(200)晶相的薄膜比(111)晶相薄膜具有更佳的力学性能.     

原位氮掺杂对CVD金刚石薄膜生长和结构的影响

以氮气为杂质源 ,采用微波等离子体化学气相沉积技术进行了金刚石薄膜的原位掺杂 ,研究了氮掺杂对CVD金刚石薄膜的形貌结构和生长行为的影响。运用SEM ,Raman ,XRD和FTIR等手段对样品进行了分析表征。实验结果表明 ,原位氮掺杂的CVD金刚石薄膜的晶面显露、晶粒尺寸、致密性、生长速率以及薄膜的微结构特征等均强烈地依赖于反应气体中氮源浓度比 ;如果氮源气体流量适当 ,杂质氮不仅能进入金刚石薄膜晶格中 ,还能与薄膜中碳原子形成化学键结合     

气调性包装材料的制备及其性能研究

采用单体六甲基二硅氮烷(HMDS)和氧气作为反应气体,采用等离子体增强化学沉积的方法在壳聚糖、PET等基材上沉积薄膜。在薄膜的制备工艺中,改变各种工艺参数制备了阻隔薄膜,通过分析沉积薄膜厚度、傅里叶红外光谱、水蒸气和氧气的透过率,探讨了薄膜性能的变化。实验证明:等离子体输入功率以及单体的比例对薄膜的选择透过性有很大的影响,利用这种工艺可以很好地改善薄膜的气体透过性。最后对薄膜的选择透过性的机理进行了初步的探讨。     

可展开薄膜结构折叠方式和展开过程研究

薄膜材料广泛运用于太空可展开航天器,薄膜的折叠和展开分析是其中的关键技术。从树叶的仿生学出发,提出薄膜结构的几种折叠方式。建立弹簧-质点系统描述薄膜材料,模拟薄膜结构的展开过程。薄膜展开过程中薄膜不可避免地发生自身的接触碰撞,提出了自接触对的判别准则,采用罚函数法有效地解决薄膜自接触问题。分析了三种折叠方式的薄膜的展开过程,并进行比较,叶外折叠方式和Miura折叠法比较适合平面薄膜的折叠。     

Numerical method of inertance tube pulse tube refrigerator

A nodal analysis method for simulating inertance tube pulse tube refrigerators is introduced. The energy equation, continuity equation, momentum equation of gas, energy equation of solid are included in this model. Boundary condition can be easily changed to enable the numerical program calculate thermal acoustic engines, inertance tube pulse tube refrigerators, double inlet pulse tube refrigerators, and others. Implicit control volume method is used to solve these equations. In order to increase the calculation speed, the continuity equation is changed to pressure equation with ideal gas assumption, and merged with momentum equation. Then the algebraic equation group from continuity and momentum equation becomes one group. With this numerical method, an example calculation of a large scale inertance tube pulse tube refrigerator is shown.     

Disappearing bodies and ghost vortices

In many dispersed multiphase flows bubbles, droplets, and particles move and disappear due to a phase change. Practical examples include vapour bubbles condensing in subcooled liquids, fuel droplets evaporating in a hot gas and ice crystals melting in water. After these 'bodies' have disappeared, they leave behind a remnant 'ghost' vortex as an expression of momentum conservation. A general framework is developed to analyse why and how a ghost vortex is generated. A study of these processes is incomplete without a detailed discussion of the concept of momentum for unbounded flows. We show how momentum can be defined unambiguously for unbounded flows and show its connection with other expressions, particularly that of Lighthill. We apply our analysis to interpret new observations of condensing vapour bubbles and discuss droplet evaporation. We show that the use of integral invariants, widely applied in turbulence, introduces a new perspective to dispersed multiphase flows.     

New one-dimensional hydrodynamics of circulating fluidized bed risers

A one-dimensional analysis of the hydrodynamics of circulating fluidized bed risers is performed following brand new mass and momentum balances for a gas–solids flow that the author has recently proposed. This analysis also includes a characteristic slip velocity between the phases derived from classical particle mechanics (the single particle equation). The predictions of the pressure drop and the solids holdup axial profiles, and the dense bed height are successfully compared with a rather limited amount of data.     

动量式气体流量计内部流场特性与测量性能研究

采用数值模拟与实验验证相结合的方法,得到了动量式气体流量计内部的流场,分析了流量变化时受力元件阻力系数的变化规律,研究了受力元件的形状、安装误差对测量性能的影响。研究结果表明,动量式流量计的阻力系数在量程范围内有较大变化,必须对阻力系数随雷诺数的关系式予以拟合;长方形受力元件阻力系数的拟合公式计算误差最小,拟合结果与实验数据的最大误差为0.32%,应优先选用;安装误差引起的阻力系数误差不大于0.32%,对测量精度影响较小,动量式流量计适合在线安装。     

Measurements of the relative momentum accommodation coefficient for different gases with a viscosity vacuum gauge

The viscosity vacuum gauges are based on the gas momentum transfer phenomena between a moving part of the gauge and a stationary surface. Thus, they may be used for the study of the momentum accommodation coefficient for various combinations of gas species and surfaces. The aim of the present work is to determine the momentum accommodation coefficient by means of the viscosity vacuum gauge with vibrating metal ribbon. The relative accommodation coefficient was computed from the measurements for Xe, Ar, He and H₂ on the bronze ribbon of the gauge in the molecular conditions. The values of the relative coefficients were 0.90 for Xe, 0.95 for Ar, 1 for He (values were normalised to data obtained for He) and 0.94 for H₂.     

基于折痕特性的柔性结构展开过程分析

研究展开过程中的折痕特性,并在弹簧质点系统基础上,提出一种基于折痕展开特性的简化分析模型,将平行折叠的柔性结构转化为折痕上的质点及连接的弹簧．分析了折痕刚度对展开的影响,给出完全展开的判定准则及通用拓扑关系,并推导了理想展开时点的运动轨迹．应用本模型对正四边形柔性结构在边框张拉受力下进行展开分析,利用自编程序通过特定功能模块实现非理想展开过程仿真．仿真展开过程与理论轨迹基本相符,验证了分析模型的合理性．并对展开过程中的受力、变形进行分析,探讨了折痕刚度对模型展开的影响．拓展了弹簧质点系统的应用范围,为柔性结构的分析、建模及仿真给出建议．     

Gasdruckschwingungsverteilung im Arbeitskanal von Seitenkanalverdichtern

The magnitude of energy transfer in side channel compressors depends on intenseness of gas pressure oscillation and transport of specific momentum in the side channel. For analysis of energy transfer from impeller to gas, the static pressure distribution and the intenseness of gas pressure oscillation in meridian profile of the side channel subject to radius and also to axial distance to impellers grid was measured with a high tightness of reading points. In order to plot the intenseness of gas pressure oscillation in meridian profile of the side channel, gas pressure oscillation in side channel has been characterized by RMS, peak value and amplitude value of gas pressure oscillation at blade rotation frequency. The results of gas pressure oscillation and tangential velocity progression in side channel from laser measurement show that the strongest gas pressure oscillations and highest velocities appear in outer region of the impeller and side channel, which refer to intense energy transfer in this region.     

The Effect of Inelastic Collisions of Molecules of a Diatomic Gas with Rotational Degrees of Freedom

The problem on Barnett slip of gas along a plane surface is solved within the suggested kinetic model for a diatomic gas with rotational degrees of freedom of molecules, which takes into account transitions from rotational degrees of freedom to translational and vice versa. The Barnett slip coefficient is obtained in the form of a function dependent on the frequency of inelastic collisions of gas molecules and on the coefficient of accommodation of tangential momentum.