非结构化网格浸入边界法的流固耦合数值模拟(英文)

This paper presents an improved unstructured grid immersed boundary method. The advantages of both immersed boundary method and body fitted grids which are generated by unstructured grid technology are used to enhance the computation efficiency of fluid structure interaction in complex domain. The Navier-Stokes equation was discretized spacially with collocated finite volume method and Euler implicit method in time domain. The rigid body motion was simulated by immersed boundary method in which the fluid and rigid body interface interaction was dealt with VOS (volume of solid) method. A new VOS calculation method based on graph was presented in which both immersed boundary points and cross points were collected in arbitrary order to form a graph. The method is verified with flow past oscillating cylinder.     

高科技助力海上大清污

<正>在"7·16"事故的海上清污工作中,遥感卫星监测、航空、航海雷达、红外线扫测、溢油漂移预测、船载溢油围收集成系统等高科技手段的运用,及时获取了溢油漂移扩散的准确动态,为海上清污行动提供了重要的决策参考,为有效地清除海上溢油污染,取得海上清     

低温对结构钢材主要力学性能影响的试验研究

钢材在低温条件下,其主要力学性能指标与常温条件下相比将发生变化．介绍了对常用结构钢材(Q235,16Mn,15MnV,16Mnq和14MnNbq)主要力学指标的低温试验研究成果,并分析了这些指标随温度变化的规律?试验结果表明．钢材的强度(屈服强度和极限强度）均随温度的降低而提高,塑性指标(伸长率和截面收缩率)随温度的降低而减小、该试验结果为进一步研究结构钢材在低温下的韧脆转变、断裂等行为提供了依据,有利于促进钢结构的推广应用。     

日产颐达轿车燃油蒸发排放系统故障诊断

介绍了日产颐达(TIIDA)轿车HR16DE发动机燃油蒸发排放系统的组成、工作原理及控制电路,说明了EVAP碳罐、油箱真空减压阀、EVAP碳罐清洁量控制电磁阀的检查方法,并对其故障诊断过程进行了阐述。     

利用遥测仪测量活塞运动

开发出一种利用新型数字遥测仪测量发动机运行时活塞运动的方法,能够确保较高的测量精度。遥测仪内有1个原始信号处理回路和1个自发电电机。整个遥测仪具有结构紧凑、质量轻的特点,能将测量活动对活塞的影响降至最小。利用遥测仪对活塞的二阶运动进行了测量,阐明了活塞重心位置、曲轴箱压力,以及添加到气缸的润滑油量等因素对活塞运动的影响。     

基层级雷达装备维修器材消耗预测模型研究

文章分析了影响基层级雷达装备维修器材消耗的各个因素,根据在各因素影响下维修器材消耗特点,对子因素建立了经典预测模型,然后运用层次分析法求得各子因素的权重,建立了最终的基层级雷达装备维修器材消耗预测模型。     

国外某重型车少片变截面钢板弹簧材料和制造工艺的研究

研究了国外某重型汽车少片变截面钢板弹簧材料的化学成分、非金属夹杂物、淬透性、显微组织、力学性能及变截面轧制、喷丸强化工艺,分析和讨论了材料化学成分、纯净度、变截面轧制和喷丸强化对少片变截面钢板弹簧性能的影响。结果表明,国外重型汽车少片变截面钢板弹簧材料为51CrV4弹簧钢,该材料具有高纯净度、高淬透性、高强度及良好的韧性,钢板弹簧在制造过程中应用了优良的变截面轧制和喷丸强化工艺,使其获得高的疲劳性能。     

空洞在围岩水平侧压力系数不同时对二次衬砌结构的影响

本文建立了山岭隧道衬砌背后空洞影响数值计算模型,并对水平侧压力系数不同时空洞对二次衬砌结构变形和内力的影响进行分析,研究结果表明：水平侧压力系数不同时,隧道衬砌结构的变形差异较大;水平侧压力系数不同时,弯矩的变化比轴力的变化更为明显,但水平侧压力系数的增加会导致轴力和弯矩都迅速增加;拱腰衬砌对拱顶空洞的产生是非常敏感的,尤其是当侧压力系数较大时,拱腰处的弯矩甚至会发生符号的改变;仰拱部位的衬砌结构在空洞产生后,随着侧压力系数的增加仰拱部位衬砌结构所受到的弯矩减小,但随着侧压力系数的增大,仰拱所受到的轴力大大增加,有可能产生压溃破坏。     

Surface reconstruction of scanned human body using radial basis functions and adaptive partition of unity

It is important to reconstruct a continuous surface representation of the point cloud scanned from a human body. In this paper a new implicit surface method is proposed to reconstruct the human body surface from the points based on the combination of radial basis functions (RBFs) and adaptive partition of unity (PoU). The whole 3D domain of the scanned human body is firstly subdivided into a set of overlapping subdomains based on the improved octrees. The smooth local surfaces are then computed in the subdomains based on RBFs. And finally the global human body surface is reconstructed by blending the local surfaces with the adaptive PoU functions. This method is robust for the surface reconstruction of the scanned human body even with large or non-uniform point cloud which has a sharp density variation. Foundation item: the National Natural Science Foundation of China (No. 50575139) and the Shanghai Special Fund of Informatization (No. 088)     

电池管理系统中电压电流检测不同步对电池内阻辨识影响的分析

针对当前电池管理系统中普遍存在的电压电流检测不同步问题,引入锂离子电池内阻等效电路模型,采用递推最小二乘算法实现对电池内阻的在线辨识.开展了基于Simulink的仿真分析,并着重讨论了各种客观因素如不同步程度、采样步长、采样噪声对内阻辨识的影响.