求平面弹性问题的更普遍的位移型解

本文得到了平面弹性问题的更普遍的位移型解答.文献[1]所得到的位移通解,只是本文的一个特殊情况.和文献[1]相比较,本文的通解中含有较多的任意常数因而可以满足更多的边界条件.     

The polynomial stress function solution for the rectangular strip bending

In this paper, we propose some formulas for seeking a part of the particular solutions of the heavy harmonics and Tricomi equations and obtain the precise polynomial solutions of the finite-item number for rectangular strip bending problem when the intensity of the distributed load varies with the fourth power of longitudinal coordinate.     

威远气田改造挖潜技术探讨

文中介绍了威远气田震旦系气藏的基本特征、开发历史及存在问题,然后分析了存在问题的原因及可能的解决办法,最后对威远气田震旦系气藏改造挖潜工作提出了一个综合治理技术框架。文中提出:通过综合治理,实现该气藏的长期稳产是可能。     

在高能气体压裂工况下井下射孔套管承载能力的有限元分析

目前国内现有的高能气体压裂技术,在1000米以上的浅地层内,能有效地将砂岩地层压裂,提高油气产量．但对于1500米以下的深地层,却不能有效地造缝,其主要原因是对套管的承压能力不明,担心提高压力会将井壁炸塌．为此,本文利用有限元法,确定了1500米井下,在不损坏套管情况下,高能气体的极限压力。     

Laminar boundary layer between two planes perpendicular to each other

In this paper, we obtain a third-order approximate solution for the laminar boundary layer between two planes perpendicular to each other.In boundary layer equations, the viscous and the inertial terms have the same quantity step. In this paper, at first, supposing that the inertial terms are bigger than the viscous terms, we solve the boundary layer equations, and then we suppose that the viscous terms are bigger than the inertial terms. At last, we take the mean value as the valid solution of the boundary layer equations.The first- and the second-order approximate solutions obtained in this paper coincide with the results in ref. [1], while the third-order solution obtained in this paper is better than that in ref. [1].     

The approximate solution of the self-similar problem for radial flow of non-newtonian fluids through porous media

In this paper, we study the approximate solution of the self-simikar problem for radial flow of non-Newtonian fluids through porous media. Assuming that the fluids obey the exponential function law, we obtain an exact solution for the exponent n=0 and compare it with the approximate solution in ref. [1]. For n>1 and n<1, we obtain respectively approximate solutions. Some exampls are presented.     

ANALYTICAL SOLUTION FOR THE SELFSIMILAR PROBLEMS OF VISCOUS FLUID FLOW

This paper presents a step-by-step approximating method to obtain the analyticalsolutions of the differential equations for the self-similar problems of viscous fluid flow(1.1-1.4).Prosnak(1969)obtained solutions of these equations by using a small paremetermethod,but he reduced the governing equations to the linear differential equations withconstant coefficients.     

小范围屈服时的应力强度因子

对于实际金属材料,裂纹前端总是存在一个或大或小的塑性区.对于小范围屈服,线弹性断裂力学分析仍适用,但必须对塑性区的影响作修正.传统的修正方法(以下简称lrwin法)[1,2],是引入有效裂纹长度的概念,即认为由于塑性区的存在,实际裂纹长度必有所增加,如取裂纹长度等于有效裂纹长度2(a+r_y),其中2a为裂纹的原长,2r_y为裂纹的增长量,则可不必考虑塑性区的存在,仍按线弹性断裂力学处理.本文则认为:由于塑性区的存在,实际的裂纹长度和外加应力均会增大.即是说,应力强度因子中的两个参量a及σ₁(外加应力)值均将改变.文中指出,按本文方法确定的应力强度因子式(3.2),较通用公式(3.4)更接近于Duffy[4]的符合实验结果的经验公式(3.6).     

对流热交换的一维非等温流动

文献[1]研究了在有稳定换热过程的管道流动中.当粘性系数μ是温度的指数函数时,在甚么条件下发生一维非等温流动.对于平面渠道及圆管的流动,还研究了速度及温度场.本文对同样问题补充提出了二种新的解法.文献[1]的方法可看成是本文方法的一个自然的分支.两个新解法中的一个只能求解文献[1]的同样问题,其计算过程的复杂程度也和文献[1]不相上下;但是另一个却能超出文献[1]的研究范围,即对管道的横截面的周界不是等曲率曲线的情形亦可求解.