Compact difference approximation with consistent boundary condition

For simulating multi-scale complex flow fields it should be noted that all the physical quantities we are interested in must be simulated well. With limitation of the computer resources it is preferred to use high order accurate difference schemes. Because of their high accuracy and small stencil of grid points computational fluid dynamics (CFD) workers pay more attention to compact schemes recently. For simulating the complex flow fields the treatment of boundary conditions at the far field boundary points and near far field boundary points is very important. According to authors' experience and published results some aspects of boundary condition treatment for far field boundary are presented, and the emphasis is on treatment of boundary conditions for the upwind compact schemes. The consistent treatment of boundary conditions at the near boundary points is also discussed. At the end of the paper are given some numerical examples. The computed results with presented method are satisfactory.     

空气水两相段塞流的跟踪模拟及试验研究

分析了前人提出的段塞跟踪模拟方法的优缺点 ,根据液塞头部的加速压降和入口液塞长度分布特征对段塞跟踪模型进行了改进。采用面向对象技术 ,实现了水平和倾斜管道段塞流的跟踪模拟 ,并与多相流试验环道的空气水试验数据进行了对比。模拟结果表明 ,当不考虑加速压降时 ,用跟踪模型预测的压降低于实测值 ;当考虑加速压降时 ,用跟踪模型预测的压降高于实测值。在管道上固定位置测出的压力信号符合正态分布 ,管道上某一固定点处液塞头部和尾部的速度分布也符合正态分布。当不考虑气泡尾波作用时 ,液塞长度沿管线增长较慢 ,分布形状无变化 ;但是考虑气泡尾波作用时 ,在入口附近液塞长度平均值增长较快 ,统计分布沿管轴向呈对数正态分布。     

边水驱油藏调剖技术

针对边水驱油藏的地质及开发特点 ,提出了边水调剖技术 ,同时对调剖井点的选择、调剖剂的筛选、调剖剂用量的确定、调剖施工工艺等配套技术进行了研究。通过向优选的调剖井注入调剖剂 ,可以控制边水的侵入方向和推进速度 ,从而增大波及系数 ,提高最终采收率。 2 0 0 0年 5月到 1 1月 ,对高 1 0 4 5区块 8口井进行了边水调剖试验 ,共注入调剖剂 1 851 6m3。调剖后 ,内部井的含水率下降、产量回升 ,明显提高了区块的采收率。数值模拟预测结果表明 ,调剖增油超过 70 0 0t,投入产出比大于 1∶2。     

Design Optimization of Charger Based on PSPICE Simulation

The design of a high-frequency switching mode charger (HFSMC) was optimized using a PSPICE simulation of the charging system including a valve regulated lead-acid (VRLA) battery pack and the HFSMC.A high-frequency battery charging circuit model was developed to describe the battery dynamics when charging with DC current having high-frequency ripples. An IGBT circuit model, a high-frequency pulsed transformer coupling model and a silicon fast recovery diode model were also developed. Simulations were compared to laboratory measurements to verify the battery and system models. Simulation of the working states of an Fe-based nanocrystalline magnetic core used in the transformer shows that the transformer design can be optimized by adjusting the core gap and by employing an RC network. Further simulations show that the components in the output unit of the charger main circuit can also be optimized. Simulations also show that the battery dynamics Including the inductance should be considered for design optimization of the HFSMC.     

地球上远程抛射体的运动轨迹及计算机模拟

本导出了远程抛射体的运动轨迹，建立了一种计算机模拟实验的方法并画出了轨道图像．为理论研究提供了一种实验方法．     

感应测井信号处理及应用研究

综合论述了感应测井信号处理方面的成果 .重点涉及感应测井信号处理理论、信号处理中几何因子选择、滤波器最优化设计、实际非线性测量信号处理的实现 .总结了常用几何因子的应用局限性 ;提出了利用相关技术、软约束技术等方法解决最优化滤波器设计中的问题 ;采用真分辨率合成与分辨率匹配技术相结合的信号处理思想 ,极大地减小了井眼附近的影响 ;实现了非线性信号自适应处理算法 .研究成果分别在双感应测井、高分辨率感应测井、阵列感应成像测井和高分辨率阵列感应测井中得到了应用     

二维磁性纳米结构材料的Monte Carlo模拟

运用Monte Carlo模拟方法，通过分折系统自旋序参数与温度的变化关系了解纳米结构材料磁性的特征．计算模拟结果表明，磁性纳米材料具有比同等大小和平均密度的单晶低的居里温度，且在相变过程中往往会出现一些亚稳态．研究结果提供了一种解析金属纳米结构材料特性的重要方法．     

考虑钢框架节点局部断裂的滞回模型

在杆端多弹簧弹塑性模型中引入了断裂机制 ,采用根据J积分撕裂模量法建立的判别裂纹失稳的失效评定图设定模型参数 .通过和有关试验结果的比较 ,验证了建立的模型及算法可以充分反映局部断裂后节点滞回性能的主要特点 .根据若干算例结果 ,归纳出适用于整体结构分析的考虑节点局部断裂的非线性弹簧模型     

轿车制动效能试验数据的回归分析与仿真

针对国产轿车道路试验中的工况控制、试验结果比较以及试验与仿真的对比等问题 ,提出了在制动效能分析中采用试验实测数据回归分析 ,并利用整车简化模型进行仿真估算的方法 ,并依此分析了原车安装防抱死制动系统后的制动效果 .该方法可为国产化轿车安装防抱死制动系统提供一种简易的分析方法     

再现轨迹的凸轮连杆组合机构优化设计

分析了再现轨迹凸轮连杆组合机构的运动原理,推导出了计算公式,并给出了该组合机构尺度综合的优化设计方法。