查询词典 boundary condition

The method is easily realized with small computation amount,and its absorption effect is better than conventional paraxial approximation absorption boundary condition.

该方法简单易行，计算量小，而吸收效果比常规旁轴近似吸收边界条件更好。

Therefore,it is necessary to research diffusion equation for suspended sediment because it describes the sediment move process in the water body.The equation is a various coefficients second-order linear partial differential equa-tion,such equation under complex boundary condition is very difficult to get its analytical solution,while its numerical solution relative analytical solution is more easier and has the obvious superiority:simple,the computation convenience.but to get a kind of difference format which is good accuracy and stability is not easy.

泥沙扩散方程实际上是一个变系数的二阶线性偏微分方程，这样的方程在各种复杂边界条件下求解是十分困难的，求它的解析解在数学上存在着难以克服的障碍，无法求出其精确解，因此常用数值方法求它的近似解，相比较而言，数值方法有着明显的优势：即简单灵活、计算方便快捷，但要寻找一种精度高、稳定性好、计算方便的差分格式也并非易事。

Numerical results for perfectly conduction and homogeneous penetrable circular cylinder are presented and compared with the solutions by using second-order differential operator B2 type absorbing boundary condition.

本文使用这种边界条件对理想导电及均匀电磁可穿透材料圆柱散射体的表面场进行了数值计算，并与使用二阶微分算子B_2型的吸收边界条件的结果作了比较。

To obtain more detailed and accurate temperature distribution inside large size hydrostatic bearing, a simulation method was present, combined with a given example of prevalent applied large size hydrostatic bearing in heavy equipment. It consisted of three dimensional numerical model and boundary condition of hydrostatic sliding way and hydrostatic sliding way inside 3-D flow. The model equations were solved by the Finite Volume Method and by selecting segregated solver of FLUENT according to CFD principle. The more accurate results of temperature rise distribution on periodic surface are obtained. The effect of partial important parameters on temperature distribution was analyzed.

为了能够数值模拟出较详细和较准确的大尺寸静压轴承内部流体的温升分布，以重型装备中所广泛应用的大尺寸静压轴承为研究对象，建立了模拟静压轴承本体及轴承内部三维流动的数学模型及边界条件；利用计算流体动力学原理，采用有限体积法并选取FLUENT中的分离式求解器进行求解，得出了轴承周期端面较准确的不对称温度分布，并分析了部分重要参数对温度分布的影响。

The physical property of the material,the space structure and the boundary condition are three important parts of the guided-wave system.

材料的物理属性、结构的空间表现和系统的边界状态是波导系统的3个组成要素。

In the symplectic system of plane elasticity in rectangular coordinates, by separating variables and abandoning the homogeneous boundary condition, the symplectic solution of a rectangular beam subjected to distributed load in a power function form is obtained.

在弹性力学平面直角坐标辛体系中，采用分离变量法，放弃齐次边界条件，得到了矩形梁侧边受幂函数形式分布荷载问题的辛解答，给出了这类问题在辛体系中的一般解法，分别对矩形梁受法向和切向分布荷载的问题进行了求解，显示了此方法的有效性。

Some new method is presented in this paper: A. An Integrated parameters computation method to analysis asynchronous operation of the turbine generator is given, including the equivalence of short circuit and open circuit of field windings, deducing boundary condition of 〓 method and computing frequency parameters. B. A new memory structure for sparse complex matrix and a PCCG method based on it are introduced to save memory and computation time. C. An equivalent method of vacuum is presented, and effectively eliminate the effect of corner point and accelerate convergence of PCCG method. D. Coupling the computation of electromagnetic and temperature field is discussed and model for computing temperature field of the turbine generator rotor at asynchronous operation is built.

文中提出了以下新方法：(1)在失磁异步运行转子三维涡流场计算中提出了完整的参数计算方法，其中包括励磁绕组开、短路的等效，〓法边界条件的推导及频率参数的计算方法；(2)提出了铁心内空气域的等效方法，有效地解决了开槽引起的角点奇异问题，并提高了方程组的迭代收敛速度；(3)在〓法有限元模型中，创立了一种能节约内存、提高计算速度的压缩存储矩阵格式，并建立了基于该格式的方程组解法；(4)提出了涡流电磁场和温度场两种不同场计算的合理结合方法，建立了转子三维稳态和时变温度场的有限元计算模型。

The scattering wave velocity potential to the flexible circle pile was the solution of the Laplace equation, which satisfied the cylindrical surface non-homogeneous boundary condition.

采用动力Winkler弹性地基梁模型模拟桩土动力的相互作用，通过求解满足柱面非齐次边界条件的Laplace方程，直接构造波浪对柔性桩的散射速度势，考虑了流体和桩体的相互作用，由解析法给出了埋置圆桩在波浪荷载下的动力响应。

The primitive variable and pressure Poisson equation formulation is employed for the numerical solution of the N-S equations, in tensor forms, on an H-0 type of non-staggered grids that makes it convenient to apply a strict inflow and outflow boundary condition.

计算网格采用H-O型非交错网格系统，易于采用严格的入流和出流边界条件。

In this topic, the dynamic analysis methods for piezoelectric vibrator are studied systematically based on the theoretical model, FEM numerical experimentation and FEM governing equation for given compound-mode vibrator, and some valuable conclusions are obtained. The main work accomplished is summarized as follows: 1.Elaborate the main modeling methods for piezoelectric vibrator and the significance and necessity to study the dynamic characteristics of piezoelectric vibrator which emphasize the urgency of this paper. 2.Take the bending deformation induced by piezoelectric ceramic as example, the energy transfer mechanism of electric energy to mechanical energy are analyzed; the motion and force transfer mechanism are analyzed for the longitudinal-bending vibrator. 3.Based on mode assumption and Hamilton principle, the coupling model of piezoelectric vibrator of linear USM is built; moreover, the equivalent circuit model is obtained and a coupling equation represents the relation between electric parameters and mechanical parameters is derived which provides foundation to match the vibrator and driving circuit. 4.Combine the constitutive equation of piezoelectric ceramic with elastic-dynamical equation, geometric equation in force field and the Maxwell equation in electric field and the corresponding boundary condition equation, the FEM control equation for piezoelectric vibrator of USM to solve dynamic electro-mechanical coupling field is established by employing the principle of virtual displacement. The equation lays the foundation to study the non-linear constitutive equation of piezoelectric ceramic driven by high-power. 5.Define the dynamic indexes of characteristic of vibrator and carry out variable parameters simulation by calculating the model parameters and the electric characteristics of vibrator are simulated according to the equivalent circuit model. By numerical experimentation, the working mode of vibration of vibrator and the shock excitation results of the working frequency band which provides the mode frequency to realize bimodal are analyzed. Detailed calculation of the electro-mechanical coupling field parameters is made by programming the FEM control equation.

本课题从理论模型、有限元数值试验、有限元控制模型等方面以复合振动模式振子为例对超声电机压电振子的动力学特性及其分析方法进行了全面系统地研究，得出了许多有价值的结论，主要概括如下： 1、阐述了目前针对超声电机压电振子的主要建模方法，对压电振子动态特性的研究意义和必要性进行了论述，突出了本文研究内容的迫切性； 2、以压电陶瓷诱发弹性体发生弯曲变形为例，分析了压电陶瓷通过诱发应变来实现机电能量转换的机理；对基于纵弯模式的压电振子的运动及动力传递机理进行了分析； 3、基于模态假定，利用分析动力学的Hamilton原理，建立了面向直线超声电机压电振子的机电耦合动力学模型，并据此建立了压电振子的等效电路模型，导出了电参量与动力学特性参量的耦合方程，为压电振子与驱动电路的匹配提供了依据； 4、从压电陶瓷的本构方程出发，综合力场的弹性动力学方程、几何方程、电场的麦克斯韦方程以及相应的边界条件方程，采用虚位移原理，建立了压电振子动态问题机电耦合场求解的有限元控制方程，为研究其大功率驱动下的非线性本构模型奠定了基础； 5、界定压电振子的动力学特性指标，对压电振子的机电耦合动力学模型参数进行计算及变参数仿真；依据等效电路模型，对压电振子的电学特性进行了仿真分析；通过有限元数值实验，对压电振子工作模态附近的模态振型及工作频率附近的频段进行了激振效果分析，找出了实现模态简并的激振频率；利用有限元控制方程，通过编程计算，对压电振子的力电耦合场参数进行了详细计算，得出了一些有价值的结论。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。