离散流

Then we summarize three basic mathematical-mechanical models of granular flow dynamics: kinetic theory model, friction-plasticity model and discrete element simulation model.

首先叙述了颗粒流研究的背景和基本概念，接着概述了颗粒流动力学研究的三种基本数学力学模型：颗粒动理论模型、摩擦塑性模型和离散元模拟模型。

Using about 3,120,000 grid cells and 512 CPUs, the parallel program has been successfully transplanted to the SZ MPP machine for massive parallel computation, giving for the first time the detailed flow properties of a model engine's combustor, offering a thorough performance analysis, and unprecedentedly obtaining some flowfield characteristics.

第三章介绍了数值计算方法及其验证。本文运用时间相关法，采用格心有限体积离散，—-—通鲤登经军巡型遇逊生匕一一一一一独立建立和发展了-谁球解混合与燃烧流场的基于PVM环境的并行计算程序。

Using about 3,120,000 grid cells and 512 CPUs, the parallel program has been successfully transplanted to the SZ MPP machine for massive parallel computation, giving for the first time the detailed flow properties of a model engines combustor, offering a thorough performance analysis, and unprecedentedly obtaining some flowfield characteristics.

第三章介绍了数值计算方法及其验证。本文运用时间相关法，采用格心有限体积离散，—-—通鲤登经军巡型遇逊生匕一一一一一独立建立和发展了-谁球解混合与燃烧流场的基于PVM环境的并行计算程序。

First of all, this paper establishes the simulation method for fluctuating wind with a multivariate normal distribution model and an autoregressive filter. On the basis of simulation results of the wind field, the time dispersion of the buffeting forces by turbulent wind is achieved.

首先，本文利用多变量正态分布模型并结合线性滤波法的自回归模型建立了脉动风的仿真模拟方法，从而实现了对紊流抖振力的时间离散。

Because the method employs the technique along the characteristics to discretize the convective term and it is unnecessary to determine the boundary condition of the vortex ahead of time, it is very convenient to solve the Navier-Stokes equation and natural convection problem.

该方法对对流项仍采用沿特征线离散技术，并且不需要事先确定漩涡度的边界条件，从而可以方便地求解流函数-漩涡度形式的Navier-Stokes方程及自然对流问题。

The percolation equation of the natural gas and the rock body deformation equation have been discreted respectively to obtain their corresponding functional equation while the calculation method was derived and the coupled solution method was presented bas...

对天然气渗流方程和岩土体变形场方程分别进行离散，得到其相应的泛函方程。根据有限元法原理推出其计算方法，并给出耦合求解方法，这对于真实模拟气藏的开发，指导气田生产具有重要的意义。

This make it difficult to know the essence of fluidized beds. In order to viewthe motion behavior of a single particle in a fluidized bed in a reasonable cost, thegas-solid flow in a fluidized bed is modeled by a combined approach of discrete particlemethod and computational fluid dynamics, in which the motion ofindividual Particles is obtained by solving Newton\'s second law of motion and gas flowby the Navier-Stokes equation based on the concept of local average.

为了用数值模拟方法来弥补传统实验方法的不足，达到从单个颗粒的尺度上来研究流化床中颗粒的运动和气体流场的剧烈变化情况的目的，本论文建立了基于用Newton第二定律计算单个颗粒运动轨迹的离散颗粒法和基于区域平均值的计算流体动力学方法的数学模型的建立和求解过程；并依据Newton第三定律建立了DPM模型和CFD模型的耦合模型，编写和调试了DPM和CFD的耦合程序。

A fourth-order compact finite difference alternating-direction-implicit algorithm is proposed for solving the unsteady-state Navier-Stokes equations of fluid flow and heat transfer using the streamfunction-vorticity formulation. Point-successive overtaxation iteration is used to achieve the steady solutions.

本文构造了求解二维非定常涡量流函数形式Navier-Stokes方程组的一种四阶紧致交错方向隐式差分算法，对包括能量方程在内的离散化方程组采用逐次超松驰迭代法求得稳定解，求解了二维非定常粘性不可压缩流体的流动与传热问题。

Side skirts continue the aggressive trend set by the new front spoiler, while at the back an impressively sized rear-diffuser accompanies two fat, ovular exhaust pipes and a small bootlid spoiler - underneath which lies a discrete 'Carlsson' badge.

侧裙继续积极趋势所规定的新的前扰流板，而在后面的一个令人印象深刻的中小型后方扩散伴随两个脂肪，胚珠排气管和一个小bootlid扰流-下面这是一个离散'卡尔松'徽章。

Firstly, based on the method of pressure-velocity coupling introduced by SIMPLE algorithm and a revised method of solving the unsteady equation of stream function and vorticity on uniform grid, a special algorithm called primitive-variable-time-dependent approach is formed in the present study. In this algorithm the Navier-Stokes equation in primitive variable form is solved by using the time-dependent approach on non-uniform staggered grid system. The second-order accuracy finite difference is used for the first and second partial derivatives of all variables of the convective terms and diffusion terms.

首先，本文在SIMPLE算法系列处理速度与压力耦合问题的思路和均匀网格下改进的关于流函数涡量方程的数值求解方法的基础上，将非定常原始变量Navier-Stokes方程的求解推广至非等距交错网格剖分，形成了具有本文特色的原始变量时间推进方法，其中对流项和扩散项中各变量的各阶导数均采用二阶精度公式，包括温度在内的离散方程组采用ADI迭代方法求解。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。