The mixing of gas-liquid flow with vapor and gas-solid flow

In the industrial production, the mixing of gas-liquid flow with vapor and gas-solid flow is a very common problem. In the process of the mixing, solid particle-clusters will form, and will have steady radii when the effect of the gathering of particles is balanced withthat of the breaking of particle-clusters. Then, the population distribution function n(a,⊄,t) of size of particles per unit length per unit volume is introduced, and its governingequation is derived on the analogy of the molecular kinetic theory. Finally, when the gas flow is very slow, the expression of steady average radius of particle-clusters is obtained.     

A note on a new theory of turbulence

In this paper,the creation and annihilaton of turbulent eddies are described aselementary particles in the quantum field theory.An elementary particle may be consideredas a solid entity as it exists in quantum theory,but a turbulent eddy is often changed in sizeand shape with time due to its energy dissipation in a turbulent field.Therefore,in order toapply the method of the quantum field theory to the turbulent field by analogy,the entity ofthe same eddy should be defined firstly.According to the linearized theory,the turbulenteddies with the similarity character in lime duration may be considered as the entity of thesame eddy,and the creation and annihilation of turbulent eddies without the similarcharacters are related to the interaction term φ_2 in equation(2.6).Then,the creationoperator and annihilation operator similar to those in the quantum field theory are used todescribe the state of turbulent eddy field.Finally,a“Schrǒdinger”equation of turbulenteddies is formulated based upon the nonline     

On the closure problem of turbulence model theory

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关于湍流理论中的不封闭性的讨论*

有一种观点认为湍流的不封闭性是由于N-S方程的非线性,这是一似是而非的错误说法。因为工程上要求的量并不仅仅限于湍流的平均速度和平均压力,即使方程式是线性的,也无法把工程上要求的这些量逐个求出来。本文论证了湍流的不封闭性来源于目前的湍流理论中缺少了一个与实际情况符合的有关分布函数,并且进一步说明了湍流模式理论的局限性和用N-S方程直接计算机模拟亦是相当困难的原因。     

The velocity of the collective motion of sedimentation of sand and clay

In this article.we shall discuss the velocity of the col-lective motion of sedimentation when the concentration ofclay particles is very high.we believe that the problemof the so-called velocity of the collective motion of sedi-mentation is not a real problem of sedimentation in physi-cal nature.but it is a problem of filtration in the porousmedium which is composed of colloidal clusters.That is tosay,those clusters consist of water and clay particles.Itis a problem of the water passing through the porous medium.Based upon this consideration.we put down the mathematicalexpression of the velocity of the collective motion of se-dimentation.In comparing with the theoretical curves withthe experimental data of the Institute of Hydraulic Research,of the Yellow River Conservancy Commission,we get congruousresults.     

泥浆的力学性质和砂粒在泥浆中运动时所受的阻力

一般认为泥浆在运动时候,它的力学性质已经有别于通常的牛顿流体而是宾汉体了.因此剪应力应该用宾汉体的剪应力关系式.本文作者则持另外一种见解.认为泥浆是一种接近于沥青一类的粘性极大,弛豫时间极长的流体.本文讨论了泥浆的力学性质,并且进一步讨论了圆球在泥浆中作匀速直线运动时所受到的阻力.在讨论过程中,我们利用了人们熟知的粘性流体绕圆球运动的Stokes解,得到了一个简单的阻力公式.当圆球在重力和浮力作用下在泥浆中作沉淀运动时候,我们求出了沉降速度.在沉降速度为零时候,我们就可以求出"不沉粒径"和"宾汉体极限剪应力"的关系.我们把计算结果得到的理论公式和陕西水科所及黄委会水科所等单位的实验数据[1][2]进行了比较,结果是令人满意的.     

The velocity of sand particles relative to water and the variation of fluctuation velocity due to the concentration of suspended sand particles

In this paper, we discuss three fundamental problems of the theory of suspended sand particles based on the theory of fluid dynamics. They are: (1) the relative velocity of sand particles to the surrounding fluid in the turbulent flow, (2) the variation of the velocity fluctuation of the fluid when the suspended sand particles exist, (3) the profile of the vertical distribution of the concentration of the suspended sand particles in two-dimensional uniform steady channel flow and the modification of usual diffusion theory. The results of our theoretical analysis are somewhat different from the corresponding expressions in the textbooks of hydraulics and river mechanics.     

泥沙对水的相对速度和含沙浓度对脉动速度的影响

本文从流体动力学的基本理论出发,讨论了泥沙运动理论中的三个基本问题.(1)泥沙在湍性水流中对水的相对速度.(2)水流挟带泥沙以后脉动速度的改变.(3)泥沙在二维渠道均匀定常流动中含沙量的垂直分布和通常的扩散理论的修正.按照我们理论分析的结果,发现和通常水力学及河道动力学中常用的表达式有一些出入.     

从流体动力学观点看半导体物理中的两个问题

本文从流体动力学的观点出发讨论了半导体物理学中间常常遇到的两个问题.其一为p-n结问题,发现过去对它的处理方法和得到的结论都是错误的.其二为方块电阻的c系数问题.发现过去对它的处理过程中的数学方法是错误的.     

THE THEORY OF SIMILARITY AND THE PROFILE OF VERTICAL DISTRIBUTION OF CONCENTRATION OF SAND PARTICLES

In this article,we treat the problem of two-dimensionaluniform steady channel flow of turbid water with theory ofsimilarity.Under the condition of similarity of turbulentfluctuation velocity and fluctuation of concentration ofsand particles,we obtain the profile of the vertical dis-tribution of concentration of sand particles.This profileof vertical distribution of concentration of sand particlesis slightly different from that obtained by diffusion theory,and departs from that obtained by gravitational theory.