Detection and analysis of transition from annular to intermittent flow in vertical tubes

In vertical co-current gas-liquid flow, the transition from annular to intermittent flow occurs when gas core becomes interrupted by liquid bridges due to the instability of the interfacial capillary waves. An analytical model is formulated to explain the liquid bridging in terms of the growth of finite amplitude interfacial capillary waves. Experimental results show that the longest wave length, which is associated with the transition, is about eight times the wave length of waves moving with the velocity of the liquid film.     

Fundamental solutions for half plane with an oblique edge crack

An elastic half plane with an oblique edge crack is considered in this paper. A pair of concentrated forces or point dislocations is assumed to act at an arbitrary point in the half plane. The half plane with an edge crack is first mapped into a unit circle by a rational mapping function so that the following analysis can be carried out on the mapped plane analytically. Then the complex stress functions are derived by separating the whole problem into two parts; one is the principal part corresponding to the infinite plane acted on by concentrated forces or dislocations, the other is the holomorphic part, which can be determined by making use of the property of regularity of complex stress functions. The stress intensity factors of the crack can be calculated with different inclined angles of the crack, and the displacement and stress components at an arbitrary position in the half plane can be expressed explicitly.     

Simulation of leachate migration in leaky aquifers

A two-dimensional cross-section finite difference model is presented to simulate density dependent leachate migration in leaky aquifers. Unlike existing models, a new approach is adopted to couple the groundwater-flow equation and the hydrodynamic dispersion equation with the elimination of the intermediate step of calculating velocities. The concept of the reference density is employed, permitting increased accuracy (over pressure-based models) in the representation of the transport process. The model is then used to study the effect of several hydraulic and transport parameters on the flow pattern and plume migration which are found to be very sensitive to most of these parameters. Equiconcentration and equipotential lines are overlapped to provide a better understanding of the coupling effect.     

液压胀形轧辊油槽深度的确定

对液压胀形轧辊（即国外的ＶＣ轧辊）辊套热装后的弹性变形进行了有限元分析，给出了确定油槽最小深度的计算公式。本文的有限元计算结果与实验结果吻合，某些结论可为液压胀形轧辊的结构设计提供理论依据。     

关于Imamura猜想1的一个结果

本文证明了GF(q)的特征为2且n为奇数时GF(q~n)在GF(q)上有自对偶正规基。     

分析恒载效应的有限元方法

本文在Takabatake关于恒载对梁静、动力影响的研究工作的基础上,导出了梁考虑恒载效应的动力分析有限元公式,提出了荷载影响刚度矩阵的概念。分析了分布和集中两种恒载型式对简支梁和悬臂梁自振特性的影响。计算结果表明,用本文方法与Takabatake应用Galerkin方法和近似闭合解方法的结果吻合良好。同时由于本文采用了矩阵形式,不仅便于编制计算机程序,且使方法有更广泛的适用性和灵活性,可更方便地用于各种不同的构造和边界条件下的实际结构。     

环件轧制中晶粒变化的计算机模拟

金属微观结构变化影响产品机械性能。本文将金属再结晶数学模型与三维热刚塑性有限元结合起来进行模拟计算，获得了环件轧制中晶粒变化的三维分布规律，及与以往不同的轧制力和力矩变化。所用方法有普遍适用性。     

双迭片弯曲压电陶瓷换能器及振动模态分析测量

介绍了双迭片弯曲压电陶瓷换能器的制作及边缘固定金属压电陶瓷双迭片弯曲振动，并利用有限元分析了换能器的谐振模式，采用激光多普勒干涉仪对换能器的谐振特性以及振动速度和位移分布进行了测量和分析，结果表明：换能器空载性能良好，通过有限元分析与先进测量手段的结合，能够对换能器器件的制作与分析进行指导。     

含钇奥氏体基堆焊焊条堆焊层研究

针对高温、磨损、热疲劳工况下服役零件的失效，研制了一种含稀土元素钇的奥氏体基沉淀强化型堆焊焊条，并对堆焊层组织与性能进行了较系统的研究。     

基于Ansys的电化学加工辅助阴极设计

根据电化学加工极间间隙电势分布的拉普拉斯方程，提出了一种阴极设计算法－误差调整法。该算法的实现主要采用了Ansys有限元计算软件。计算结果表明：该法计算迭代次数较为适当，对于精度要求不高的电化学加工阴极设计，基于Ansys的辅助阴极设计有效可行。