油门踏板杆材料的断裂优化分析

针对上海通用别克桥车油门踏板总成踏板杆在国产化过程中出现了100万次疲劳试验断裂，进行了材料成分、力学性能、有限元分析、台架试验等分析，找到了材料替代中硬度低的原因，提出了最佳的硬度值。     

天然气发动机最高转速准均质压燃特性的研究

就国产6110增压中冷发动机燃烧天然气的一些性能进行了研究。在压缩终了被少量柴油引燃的均匀天然气混合气的燃烧接近均质压燃燃烧过程。采用了发动机缸内分析以及相应工况的排放测试对比分析方式，对发动机的燃烧特性进行了试验研究。     

Modeling gas dissolution in deepwater oil/gas spills

Gases in deepwater oil/gas spills can lose considerable amounts of the gas phase due to dissolution in water. Gas dissolution has a significant impact on the behavior of the oil/gas jet/plume because of its impact on the buoyancy. A method is presented in this paper for computing gas dissolution that covers a broad range of water depth, from shallow water where gases behave as ideal ones under low pressure to deepwater where gases behave as non-ideal ones under high pressures. The method presented also accounts for the spherical and non-spherical shapes of gas bubbles. The gas dissolution computations are validated by comparing the computed results with observed data from previously conducted laboratory experiments. The gas dissolution computation module is then integrated with a model for underwater oil/gas jets/plumes by Yapa and Zheng [J. Hydraul. Res. 35 (5) (1997) 673]. Scenario simulations are presented to show the impacts of gas dissolution on the behavior of jets/plumes. These scenarios show the impact of dissolution on the behavior of the jet/plume. The comparison of results using ideal gas conditions and non-ideal gas conditions is also shown.     

船舶尾板振动性能研究

通过应用有限元法和流体边界元法对船舶尾板的振动性能作较全面的分析研究,从而了解尾板自身的振动特性及尾板对船体结构振动响应的影响,为尾板的设计提供结构动力性能方面的依据。     

船舶结构疲劳强度分析中的几个问题

讨论了有关确定船舶结构疲劳寿命的几个重要因素;应为周期数、Ｗｅｉｂｕｌｌ分布形状参数ξ与船长关系、热点应力和切口应力等。以２５８,０００ｔ现有超大型油船（ＶＬＣＣ）的舷侧纵骨和甲板纵骨的疲劳强度为例进行了计算,计算结果表明预示的疲劳寿命较好反映了超大型油轮的疲劳寿命。     

液化天然气专用码头系泊安全操作仿真研究

考虑液化天然气码头对安全的特殊要求,结合船舶系泊作业中的诸多因素,以液化天然气专用码头为例,运用船舶操纵模拟器对液化天然气船靠离码头的过程进行仿真实验,由此分析港口水域的风、流、浪及回旋水域尺度等因素对液化天然气船系泊作业的影响,为船舶靠离泊安全操纵提供参考数据,也可为液化天然气码头的建设提供科学的论证。     

液化天然气动力船供气系统动态模拟

本文以液化天然气(LNG)动力船供气系统的工作流程为原型,讨论发动机在工况变化时如何设置控制方案,以达到更好的温度控制效果,满足双燃料发动机的工作需求。使用Aspen HYSYS流程模拟软件对该工作流程进行模拟,研究动态模拟时系统的运行情况。针对供气时的工况变化,改变液化天然气的流量,同时供气温度需要稳定在一定范围内,提出两种维持供气温度相对稳定的调节方案：改变热源的供热量或调节加热介质（水乙二醇）的流量,在HYSYS中分别进行动态模拟。改变热水流量时,输气温度可以控制在20℃-32℃;改变水乙二醇流量时,输气温度控制在22℃-28℃。两种调控方式结合的综合方案中,天然气温度也较好稳定在22℃-28℃之间,并且不需要引入其他外加冷源,响应较快,最适合应用于实际系统中。     

一种步进电机控制的气体压力闭环控制系统的设计与实现

介绍了一种步进电机控制的气体压力闭环控制系统。该系统的主控计算机根据气体实际注入情况和预期的注入设定值进行准确计算后,控制步进电机驱动卡驱动相应的步进电机,调节精密减压器的开度,从而确保工作气体的长时间、高精度恒压注入。本系统具有控制精度高、控制速度快、通用性好、价格低等特点。     

The overall effects of road works on global warming gas emissions

Road characteristics influence the amount of pollution generated by traffic. They govern the rolling resistance, which includes: the viscoelastic behaviour of the pavement structure, surface texture, and profile unevenness. Road works are performed on a periodic basis to maintain these characteristics at proper levels of service (e.g. safety, comfort, and noise). While such works produce additional pollution (due to congestion around worksites or extra fuel consumption along the detour route), they still result in less pollution over the long term. This article assesses the balance between an increase in gas emissions during road works and the reduction in emissions from traffic once the works are completed. It is demonstrated that when road works are introduced to correct longitudinal profiles, rather than texture, the emissions benefit is substantial.     

基于运行模态分析的船舶推进轴系状态监测

论文提出一种基于运行模态分析(OMA)的新的船舶推进轴系状态监测方法。论文以船舶推进轴系试验台为试验对象,获取轴系运行时不同加载工况下的扭振信号,利用基于数据的随机子空间法(DD-SSI)识别扭振的固有频率,并与已知的试验模态分析(EMA)识别的轴系静态时同一加载工况下的结果进行对比,验证运行模态分析识别结果的准确性,并研究不同加载工况下轴系扭振固有频率随加载工况的变化规律。试验结果表明,运行模态分析能够准确识别轴系的扭振固有频率,且扭振固有频率的增量与加载量呈正相关,因而运行模态分析可以用作一种新的船舶推进轴系状态监测方法。