查询词典 convection

The transient natural convection and natural convective heat and mass transfer under constant-flux condition were also studied respectively. In experimental research, the electrochemical method was used to analogize natural convection in a porous enclosure.

在实验研究中，采用电化学方法，在多孔介质封闭腔体的两竖壁间建立浓度梯度和温度梯度，实验测量了腔体内的温度分布和电极间的极限电流，以此确定了总体的传热系数和传质系数。

A numerical calculation program is written up for the various solution methods in this paper and the program is being used in various aspects of inverse problem of environmental hydraulics, including inverse problem in reverse process of one-dimensional unstable diffusion, inverse problem in reverse process of convection-diffusion, inverse problem for the dispersion coefficient in water quality model, The inverse problem of coefficient identification for nonlinear Boussinesq equation, parameter identification inverse problem for water quality model, the inversion of parameter of BOD-DO water model, the inverse problem of the source of convection-diffusion, identification of the steady-state permeability for two dimensional isotropic medium, two-dimensional steady inverse problem of convection-diffusion and parameter identification inverse problem for two-dimensional parabolic equation, etc.

对本文提出的各种算法，编制了数值计算程序，并把它应用于环境水力学反问题诸多领域，包括污染物一维非恒定扩散逆过程反问题，对流扩散方程逆过程反问题，河流水质纵向弥散系数反问题，非线性Boussinesq方程反问题，河流水质多参数识别反问题，BOD-DO水质模型参数反演问题，对流—扩散方程源项反问题及二维恒定各向同性介质渗透系数反问题，二维定常对流——扩散方程及二维抛物型方程参数控制反问题等。

Our results indicate that not only the poloidal convection patterns in uppermost mantle have good correlations to surface tectonic motion, but also the toroidal ones reveal important information of their horizontal motion and rotation for the first time. There is a SEE_NWW strong convection zone close to the equator in toroidal convection patterns, which probably correlates with the large_scale shear zone near the equator and is the deep dynamic background of strong earthquake occurrence in this zone. The opposite rotating large_scale convection rolls in the Southern and Northern hemispheres suggest that maybe there is differential rotation between them.

研究结果表明，不但地幔浅部的极型场对流图像显示出了与大地构造运动的相关性并揭示了其深部动力学过程，更重要的是，地幔浅部的环型场对流图像首次为我们认识和理解板块构造的水平与旋转运动提供了重要的信息：环型场速度剖面中在赤道附近存在一条大致南东东—北西西向的强对流条带，可能与环赤道附近大型剪切带的形成相关，进而表明可能是该带强震发生的深部动力学背景；在南北半球存在的旋转方向相反的对流环表明它们整体上可能存在差异旋转。

The results show that the increasing Marangoni number will lead to more nonlinear distribution of temperature field, but streamfunction of the cell center; vorticity on the wall and peak value of velocity diminish first, then increase, finally lose stability. The thermocapillary convection in the whole liquid zone appears to get stronger along with the augmentation of Prantal number. The effect of increasing of Biot number on temperature and flow fields is not obvious although the convection is strengthened a little. As increasing the aspect ratio A, thermocapillary convection induced by temperature gradient and liquid viscosity becomes stronger.

结果表明：温度场的非线性分布随着Ma数的增大而加剧，但对流涡胞中心流函数、壁面涡量和轴向、径向速度峰值并不象温度场随着Ma数的增大而单调增大，而是先减小，然后增大，最后失稳，表明Ma数对热毛细对流的影响比较复杂，针对不同的物理模型，会导致完全不同的流态；Pr数愈大，流体的热扩散能力在粘性扩散与热扩散能力之比中愈占支配地位，当Ma数一定时，热毛细对流随Pr数的增大在整个液体区域内有增强的趋势；Bi数增大，热毛细对流有所增强，但不甚明显；A的增大使得由温度梯度和流体粘性诱导的热毛细对流随之增强。

In this paper, a high order accuracy difference method is presented for solving unsteady convection diffusion equation by using Implicit Perturbation Finite Difference scheme. Firstly, we use the steady convection diffusion equation, the constant coefficients of this equation are expanded to power series of grid-spacings, then the high-order Perturbation Finite Difference scheme is obtained by determining the coefficients of the power series. Put this scheme on unsteady convection diffusion equations and modified it, the IPFD scheme is constructed.

本文利用摄动差分思想，对定常对流扩散方程中的空间微商系数进行摄动展开，展开幂级数系数通过消去摄动格式修正微分方程的截断误差项求出，由此获得方程的隐式摄动差分格式，将此方法应用于非定常对流扩散方程，并加以修正，得到该方程的修正隐式摄动差分格式。

By using the Eulerian-Lagrangian combined method, the convection-diffusion equation is spitted into the diffusion terms and convection terms. For convection terms, the implicit method of characteristics using time-line interpolation with high accuracy is adopted. While for the diffusion terms the conventional finite difference method is used.

采用欧拉—拉格朗日混合解法，将对流—扩散方程中的扩散项和对流项分裂求解，应用高精度时间序列插值的特征差分隐格式求解对流项，扩散项采用传统的有限差分法。

Experiment results show as follows in the processing of semiconductor etching, chemical heat centers in the semiconductor material, and is convected gradiently in all directions; the vertical heat convection velocity is obviously swifter than the horizontal; the process of heat convection can be real- timely recorded, and the heat convection situation can be gotten in any small area at any time by infrared camera which makes the analyse and understanding of heat convection characteristic in the processing of wet etching more intuitionistic.

实验结果表明：在半导体腐蚀过程中，化学热以半导体材料为中心，向四周梯度状对流；向上的热对流速率明显大于水平的热对流速率；红外热像仪可以实时纪录热对流过程，并获得任意时刻、任意小区域的热对流情况，使得对湿法腐蚀过程中热对流特性的分析和理解更加直观。

The research results are as follow: 1. Through the air convection experiment in laboratory, we find that the real measurement of natural convection in laboratory under obturated circumstances is almost sameness to theory calculation. The most notable part of air convection is in the middle part of crushed stones. The bigger the size of the crushed stones is, the bigger the measured wind value is.

主要结论如下： 1、通过室内模拟自然对流试验，得出在室内封闭条件下测得的自然对流效应跟理论计算值相差不大，自然对流效应最明显的部分位于块石层的中间部位；实测的对流涡包都是由一开始的无序状态往块石层的中间部位发展；随着块石粒径的增大，测得的最大风速值也随之增大。

Any high Re number flow over bodies consists of three basic flows: the flow with convection-dominant in all spatial directions, the flow with convection-diffusion competition in all directions and the flow with convection-dominant in part directions and convection-diffusion competition in part directions, which is called the interacting shear flow; the features of the three basic flows are different; their simplest conservation equations, i.e. the Euler equations, Navier-Stokes equations and diffusion parabolized NS equations, have different mathematical characteristics; there is a great disparity in domains of the three basic flows and the domains of NS equations are very small. Therefore, adopting Euler-DPNS-NS equation system to analyze and compute high Re number flows over bodies is a logical approach. There exists a mutual examined-complemented relationship of this approach with the usual one of adopting only NS equations.

主要内容如下：（1）高Re数绕流包含3种基本流动：所有方向对流占优流动、所有方向对流扩散竞争流动和部分方向对流占优部分方向对流扩散竞争流动，3个基本流动的特征彼此不同且在流场中所占领域大小彼此相差悬殊，NS方程区域很小，它们的最简单控制方程组Euler、Navier-Stokes和扩散抛物化NS方程组的数学性质彼此不同，因此利用Euler-DPNS-NS方程组体系分析计算高Re数绕流流动就是一个合乎逻辑的选择，该法与利用单一NS方程组的常用方法可以彼此检验和补充。

Evaluates the zero-equation model provided by Chen based on CFD simulation of three typical airflows(forced convection,mixed convection and natural convection)in air-conditioned and ventilated rooms.

为了对Chen提出的零方程模型进行评价，研究了三种典型的空调通风房间气流组织工况(强迫对流、混合对流和自然对流)，同时采用Prandtl的混合长度理论和双方程K-ε湍流模型的计算结果作为比较。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失