基于粘性阻尼的地埋式旋转喷头限速系统研究

介绍了现有地埋式旋转喷头的结构及其减速机构的工作原理,分析并指出了其存在的传动比大、效率低下等不足.在此基础上,开发了一种基于粘性阻尼传动的新型限速机构,基于数学模型的仿真分析表明其输出转矩与转速成近似正比关系,具有良好的调节线性和稳定性,能够显著提高喷头输出转速的平稳性,并且具有低成本、高效率的优点,可满足农作需要.     

Effect of damping model on pre-yielding earthquake response of structures

The present paper examines differences between responses of single-degree-of-freedom (SDOF) systems with viscous and hysteretic damping to earthquake ground motions. Only responses within yield limits are considered. The structural behavior of SDOF systems with hysteretic damping is modeled by a generalized elasto-slip model of the Masing type. The model leads to a force–displacement relationship similar to that proposed by Ramberg and Osgood. The responses of the two systems are compared for a number of earthquake records. To achieve consistent comparison, parameters of the linear system with viscous damping are determined by the secant stiffness method. In many cases significant differences in the peak displacement responses and energy values have been observed between the systems. This indicates that the prediction of the response of structures to earthquake ground motions before yielding based on linear models with viscous damping may not be as accurate as used to be believed. Tentative estimates of error associated with such predictions are presented.     

粘介质成形工艺特点与应用分析

简要介绍了近来出现的利用粘性介质传压进行冲压成形的一种新工艺。通过粘介质成形实验与以水为介质的液压成形模拟的对比分析,得出了ＶＰＦ过程中的一些工艺特点,并分析了ＶＰＦ工艺在飞行器制造中的应用前景。     

齐40块稠油油藏聚合物驱可行性室内实验研究

分别用人造岩心和人造均质平面模型，在实际油层条件下研究了辽河油田齐４０稠油油藏实施水驱及聚合物驱的室内驱油效率及驱替特征。在驱油实验中用核磁共振成象技术研究了稠油油藏水驱和聚合物驱的驱油机理。结果表明，在一定条件下，稠油油藏在蒸汽吞吐后实施聚合物驱是可行的；聚合物驱主要通过扩大波及范围和增加坟差来提高驱油效率，聚合物驱后仍有大量的残余油滞留在孔隙介质中。     

螺杆泵在稠油出砂井中的应用

本文介绍了螺杆泵采油系统基本结构和工作原理，根据螺杆泵在稠油出砂井中的现场应用，分析了螺杆泵现场应用效果以及现场施工时要求，展现了螺杆泵采油系统在高粘稠油和出砂井等方面良好的现场应用前景。     

对拓宽油气资源领域的一点意见

我国油气工业的发展在于：①逆冲断裂带的勘探。②非构造类型油气藏的勘探，如岩性油藏、尖灭油藏、水动力油藏等。这两类领域的勘探要提高地球物理勘探工作的水平。③水合物天然气藏应给予足够的注意。国外开采特稠油油藏的经验要注意学习，为我所用。（秦同洛摘     

辽河油田杜84块超稠油油藏水平井开采数值模拟

针对辽河油田直井注蒸汽开采超稠油油藏效果差的实际情况，利用最新研制的水平井热采数值模拟软件———ＮＵＭＳＩＰ－４软件，研究了杜８４块不同水平井布井方式和开采方式的开发效果。结果表明，该块最佳开采方式为蒸汽辅助重力驱，并采用成对水平井组合，上注下采，水平段长３００ｍ，注采井距１５ｍ的布井方式。该项研究成果可以为类似超稠油油藏的开发所借鉴。     

The vibration rheometer: the effect of vibration on fresh concrete and similar materials

The use of the newly‐designed electronic accelerometer as an integral part of the vibration rheometer, for the first time made it possible to continuously and accurately record the acceleration of an apparatus piston as a solid mass oscillating in the test specimen of the material under sub‐base excitation. The research is focused on plastic concrete, mortar and appropriate reference materials whose behavior was approximated to a pseudoplastic fluid. An analytical solution to the oscillation of the piston in the specimen is also provided. The research showed that a layer of the material with the properties close to the ideal Newtonian fluid forms around each particle exceeding 0.25 mm causing a reduction in resistance to deformation and compression in a specimen. The effect of vibrations on plastic concrete and similar materials is also described.     

粘性不可压流动的全离散非线性Galerkin方法

这篇文章讨论了有限元情形下，粘性不可压流动的全离散非线性Ｇａｌｅｒｋｉｎ方法，此外，给出了用非线性Ｇａｌｅｒｋｉｎ方法进行的数值试验结果，和通常的Ｇａｌｅｒｋｉｎ方法比较，非线性Ｇａｌｅｒｋｉｎ方法是一种稳定性好，计算量少以及逼近精度高的数值方法。     

A boundary element study of the effect of surface dissolution on the evolution of immiscible viscous fingering within a Hele-Shaw cell

Fingering instabilities at the interface between two immiscible fluids can appear during the displacement of a fluid of higher viscosity by another one of lower viscosity. The evolution of the finger structures is determined by the interface kinematic and dynamic matching conditions, which describe mass and momentum conservation across the interface. In the case when the injected fluid is a gas and the resident one is a liquid, dissolution of the injected gas into the displaced liquid can occur at the interface between the two phases. In this case, the transfer velocity of the dissolved gas reduces the interface displacement velocity as described by the kinematic matching condition, delaying the evolution of the fingering. In addition, the momentum flux across the interface, due to the dissolution, modifies the dynamic matching condition with possible changes in the patterns of the fingers structures.This work studies the effects of gas dissolution on the evolution of fingering instabilities during the displacement of a viscous liquid by an immiscible injected gas in a Hele-Shaw cell. A boundary element numerical simulation of the growth of the injected gas bubble is developed and implemented. This numerical model takes into account the dissolution across a sharp interface between the two phases. Our numerical simulations suggest that the inclusion of gas dissolution can lead to the eventual breaking of the fingers. These “shed fingers” become individual bubbles, which move away from the injection source with the velocity of the surrounding fluid and eventually will dissolve into the ambient fluid. New fingers evolve, with their concurrent breaking, resulting in the possibility of a cascade of travelling and dissolving bubbles, instead of a continuous fingering structure.