A mathematical model that describes the transient flow is developed based on the conservation law of mass momentum and energy followed in the course of transient flow process of gasliquid phases.
根据气液瞬变流动过程中所遵循的质量、动量和能量守恒定律，建立了描述气液两相瞬变流动的数学模型。
Through building a mathematical model of gas water heater and using the non- structure grid and the K? εdouble equation model as a turbulence model, we can establish the closed equations composed with the continuity equation, the momentum equation component, K equation andεequation. Using eddy dissipation components combustion model, definition boundary conditions in turbulent flow of chemical composition mix and reaction, separation solver used for initialization and solve combustion model, we can obtain the temperature、pressure distribution of gas water heater, as well as CH4, O2, NO mass fraction of the concentration of distribution in combustion process. Through these distributions, the temperature field and each kind of combustion component characteristic were obtained, including some problems that in the design needs to be pay attention to. Through changing the air speed of flow in the software control panel, the difference of the combustion temperature and each kind of gas mass concentration distribution under the different excess air coefficient was obtained.
通过构建燃气快速热水器的数学模型，采用非结构化网格和K-ε双方程模型作为湍流模型，建立由连续方程、动量方程、K方程和ε方程组成的封闭微分方程组，使用涡耗散组分燃烧模型，定义带化学组分混合与反应的湍流流动边界条件，使用分离求解器初始化并求解燃烧模型，得出了新型燃气热水器内温度场、压力场的分布，以及燃烧过程CH_4、O_2、NO等气体质量分数浓度分布，通过这些分布，得出了温度场和各种燃烧组分的特点及设计中需要注意的一些问题；通过在软件控制面板改变空气流速，得出了不同过剩空气系数下燃烧温度及各种气体质量浓度分布的差异；另外，通过对热水器的引射器进行计算，发现其不能满足引射能力的要求，建议选用完全预混负压吸气引射器，并计算出了其尺寸。
Textile Group ruentex started since the establishment of the circulation into the flow of the cause of RT-Mart Corp., its very rapid development momentum.
纺织起家的润泰集团，自投向流通领域成立大润发流通事业股份有限公司以来，其发展的势头迅猛无比。
By considering the momentum source term of surface tension as well as the source term of heat and mass transfer in gas-liquid two-phase flow, a computational model based on the Volume of Fluid algorithm was established to describe the heat and mass transfer of two-phase falling film in a plate-type evaporative condenser.
在考虑表面张力动量源项和气－液两相间传热传质源项的条件下，基于Volume of Fluid算法，建立了板式蒸发式冷凝器气－液两相降膜流动传热传质的计算模型。
In the meantime, temperature profiles of bed were investigated in adsorption and decompression procedure by the adiabatic experiment and the coincidence between temperature wave and concentration wave was observed. Adiabatic experiment revealed the relation between temperature wave andconcentration wave in bed and showed that pressure swing adsorption of air separation for O2 product was a non- isothermal process. Secondly, pressure swing adsorption of air separation was calculated and analyzed based on mathematical models, which fully considered the mass-transfer, heat-transfer and momentum-transfer of non-isothermal process. The mathematical models consisted of axial dispersed plug flow models of fluid, energy balance models of gas-solid and bed wall, adsorption equilibrium model of LRC and mass transfer model of LDF, which was designed for six-step cyclic process(feed repressurization, adsorption, cocurrent depressrizing pressure equalization, counter-current depressrization or evacuation, product purge and countercurrent pressuring equalization).
针对一定设计要求（3000Nm`h，93％OZ）的 CZAVSA、LIX－VSA和 C.A－VSA过程进行模型化计算和工艺条件的敏感性分析，结果表明：VSA过程中的氧收率和能耗与所参照体系的实际值基本吻合，验证了选用的模型和计算方法以及模型参数的合理性，为变压吸附空分制氧过程的计算和优化提供了可靠的模型化手段，而且通过模型化计算得出床层内浓度和温度在不同步骤中变化也证实了循环过程中均压和冲洗步骤的必要性；（2）相同吸附剂量的前提下，CaA－VSA过程的收率明显高于CaA干SA过程且能耗远低于用A过程，CaA干SA过程更适合对能耗要求不高的较小规模氧的生产，而CaA刁SA过程适合较大规模的生产；o VSA过程有高的氧收率和产率，在装置投入、能耗和生产规模比CaAVSA过程有非常显著的优势，更适合大规模氧的生产；（4）VSA过程中吸附压力、脱附压力、循环时间和吸附柱长对产品气中氧纯度、收率和产率影响显著，而吸附压力、冲洗比、循环时间和吸附柱长为PSA过程的显著性因素，获得了影响VSA和PSA空分制氧过程的主要因素。
The results showed that larger momentum ratio, narrower width of the aperture, and 90° angle between wall jet and axial flow promoted a better flow field in the mixing zone.
进一步利用计算流体力学手段对相应的流场进行了模拟，与PIV实验结果吻合很好，验证了模型对冷态流动的预测能力。
And the downstream flow of the muzzle changes when the droplet diameter or momentum flux ratio varies.
雾化液滴直径的大小或者动压比的大小对喷口下游流场的影响区域是不同的。
The whole course to solve the finite element analysis of 3D viscoelastic coextrusion flow was presented. During the solution of viscoelastic equation by coupling format, the stress was divided into purely-viscous component and elastic component, the Streamline Upwind method was used to correct the convection term in momentum equation. The kinematics and dynamics condition of moving free boundary and die swell boundary were analyzed. The solution step of the free boundary problem was presented. The non-linear equation was solved by the evolution arithmetic method. It was shown that this technique is an effective method to solve the non-linear problem in polymer melts coextrusion simulation.
根据粘弹流体耦合格式有限元计算的基本方程，提出了在求解基本方程的过程中，对应力采用粘弹分量格式，以简化求解，采用对动量方程中的对流项进行迎风修正，形成非协调流线迎风有限元格式的方法解决对流项占优时数值解振荡问题；研究了共挤出过程数值模拟中所涉及的自由边界问题，分析了计算自由边界条件所需要的运动学条件和动力学条件，给出了自由边界问题的求解步骤；提出了用参数渐变算法逐渐逼近收敛值的思路，通过计算证明该算法是解决聚合物共挤出流动模拟非线性问题的有效方法。
The swirl-producing ability, characterized by angular momentum swirl ratios, of different intake ports was analized, and compared with swirl ratios measured by vane anemometry in steady flow rig.
利用进气道气门口流速稳态测量数据，计算并比较了直气道和斜气道气门口速度分布产生的进气涡流角动量的时间历程，证实了由于气门口速度分布不同，不同气道产生的角动量的大小和成份也不同，提供了一种评价气道性能的微观分析方法。
The momentum of traffic flow is redefined while the assimilating relationship between traffic flow and fluid flow is adjusted.
提出了新的交通流连续性假设，引入了车域和定常交通流的概念，重新定义了交通流的动量，调整了交通流与流体流的比拟关系。
Based on the free radical reaction kinetics, kinetic models of the free radical polymerization and grafting were constructed, and expressions of reaction rate, monomer concentration, monomer conversion and initiator concentration were deduced. According to the statistical theory of polymeric reactions, the average molecular weight can be divided in three hierarchies: the first is that of polymer chains instantaneously produced, the second is that of polymer chains considering the cumulative effect and the third is that of the fluid with both the reactant and the production taken into account. Expressions of the number-average molecular weight and weight-average molecular weight for each hierarchy were constructed. The continuity equation, the momentum equation as well as the initial and bondary conditions were derived to describe the viscous incompressible fluid flow process. On the basis of polymer physics, expressions of zero shear viscosity and apparent viscosity related to processing conditions and material structures were built.
结合上述空间模型，给出了反应挤出过程的化学反应场、材料结构场与化学流变场的基本控制方程：根据自由基反应动力学理论，构建了自由基均聚及接枝反应的动力学模型，得到了反应速率、单体浓度、单体转化率、引发剂浓度的计算式；根据高分子反应统计理论，考虑相对分子质量三层意义上的统计平均——瞬时生成的聚合物平均相对分子质量、考虑了历史累积效应的聚合物平均相对分子质量与同时考虑反应物和产物的整个材料体系的平均相对分子质量——构建了每个层次数均、重均相对分子质量的计算式；给出了黏性不可压缩流体流动过程的连续性方程、运动方程和边界条件；根据高分子物理学，建立了反应体系的零剪切黏度、表观黏度与工艺条件、材料结构的关系式。
Interfacial momentum transfer and velocity slip during the relaxation process of high speed gas-droplet two-phase flow are stu...
超音速气—雾两相瞬态流动特性对低温等离子体—液相反应体系的传质与混合具有十分重要的影响。
In addition, k-ε model is used to calculate the flow field of downshot flame furnace. The effects of momentum ration between arch air and side-wall air, injection angle and elevator of staging air are similar to modeling test results.
在对PAX燃烧器的进行冷模试验和数值模拟的基础上，对拱顶风为旋流的W型火焰炉进行了冷模试验研究，着重于拱顶风旋流强度、拱顶风侧墙风动量比、分级风入射角度和入射位置对炉内流场的影响，并认为在采用旋流燃烧器时，拱顶风旋流强度对w型炉炉内流场起着关键性的作用。
Vibration tube from install in vibration the tube carry the electromagnetism of department to drive the vibration that the coil drives to make to looklike in the sound fork, be fluid in flow discharge tube is accepted discharge compulsory to take care of of the perpendicularity exercise, heading uping oscillatory half aperiod in the discharge tube, flow to resist a pipe to heading up to exercise asto it's the perpendicular momentum increase but the amount of convection takecareof a house a dint for getting down.
振动管由安装于振动管端部的电磁驱动线圈驱动作近似于音叉的振动，当流体流入流量管时被强制接受流量管的垂直运动，在流量管向上振动的半个周期时，流涕反抗管子向上运动对其垂直动量的增加而对流量管事家一个向下的力。
Vibration tube from install in vibration the tube carry the electromagnetism of department to drive the vibration that the coil drives to make to looklike in the sound fork, be fluid inflow discharge tube is accepted discharge compulsory to take care of of the perpendicularity exercise, heading uping oscillatory half aperiod in the discharge tube, flow to resist a pipe to heading up to exercise asto it's the perpendicular momentum increase but the amount of convection takecareof a house a dint for getting down.
振动管由安装于振动管端部的电磁驱动线圈驱动作近似于音叉的振动，当流体流入流量管时被强制接受流量管的垂直运动，在流量管向上振动的半个周期时，流涕反抗管子向上运动对其垂直动量的增加而对流量管事家一个向下的力。
Momentum of the injector effluent streams can contribute to lateral flow, either intentionally or un intentionally.
喷注器单元喷注射流的动量可能有意或无意地影响横向流。
Momentum of the injector effluent streams can contribute to lateral flow, either intentionally or unintentionally
喷注器单元喷注射流的动量可能有意或无意地影响横向流。
By using the theories of conservation of momentum, conservation of energy and hydrokinetics, a mathematical model for describing the relationship among the fluid parameters, the formation parameters and the vibrant operation parameters was established. The analytic solutions of one-dimensional and radial transfusion equation for compressive and single-phase fluid flow through the compressive formation were obtained. The effects of each parameter on the vibrant operation were also gotten. On the basis of the above results, the computation models were established.
应用动量守恒、能量守恒、流体动力学等基本原理，建立了地层参数、流体参数和振动作业参数之间相互耦合的数学模型，求出了单相微可压缩流体在可压缩地层中的平面一维和平面径向渗流方程的解析解，得到了各项参数与振动作业效果之间的关系，为振动采油的数值模拟提供了初始压力分布表达式。
In this paper, such disciplines as polymer chemistry, polymer physics, statistical theory of polymer reaction, computational fluid dynamics, mechanical science and software engineering were used together to analyze the reactive extrusion process for the anionic polymerization and copolymerization. The conservation equation of momentum, continuity equation, and the numerical calculation equations of monomer conversion, the average molecular weight and viscosity were numerically solved by means of the finite volume method and the uncoupled semi-implicit iterative algorithm. And then, the evolutions of such variables as flow velocity, shear rate, pressure, released heat of reaction, reactive calorific intensity, polymerization rate, monomer concentration, monomer conversion, average molecular weight, fluid viscosity were obtained quantitatively under the given initial and boundary conditions.
本文综合应用高分子化学与物理、高分子反应统计理论、计算流体力学、机械科学和软件工程等学科知识，研究阴离子均聚体系、共聚体系的反应挤出过程，采用有限体积方法和解耦合的半隐式迭代算法，数值求解动量守恒方程、连续性方程、单体转化率的数值计算式、流体平均分子量的数值计算式、流体粘度的数值计算式，在给定的初始条件和边界条件下定量获得聚合体系在挤出过程中的流动速度、剪切速率、压力、反应热强度、反应热的释放量、聚合速率、单体浓度、单体转化率、平均分子量、材料粘度等物理量的动态演变情况。
By combing the constitutive equation of Bingham fluid with the momentum equation, the velocity profiles of the Bingham fluid in a concentric annulus with an moving inner pipe were obtained by the dimensional analysis in order to analyze the effects of the movement of inner pipe on the flow of Bingham in annuli.
为了分析内管的运动对宾汉流体在环空内流动规律的影响，将宾汉流体的本构方程和运动方程相结合，利用因次分析的方法，得到了宾汉流体在内管作轴向运动时环空内的速度分布。