保证高等级公路沥青混凝土路面平整度的工艺措施

以西宝高速公路西段沥青混凝土路面的施工为例，从施工准备、摊铺、碾压及其它工艺环节控制等方面，详细介绍了要保证高等级公路沥青混凝土路面平整度施工工艺方面应采取的措施。     

我国民用汽车拥有量的计量经济模型与分析

根据近二十年来国内多项经济指标,运用逐步线性回归的方法建立了民用汽车拥有量的计量经济模型,并对模型进行评价和检验。利用该模型可以对今后的民用汽车拥有量进行理论预测,为发展规划提供有依据的理论指导。     

Aerodynamic design optimization of rear body shapes of a sedan for drag reduction

This study proposes an aerodynamically optimized outer shape of a sedan by using an Artificial Neural Network (ANN), which focused on modifying the rear body shapes of the sedan. To determine the optimization variables, the unsteady flow field around the sedan driving at very fast speeds was analyzed by CFD simulation, and fluctuations of the drag coefficient (C _D ) and pressure around the car were calculated. After consideration of the baseline result of CFD, 6 local parts from the end of the sedan were chosen as the design variables for optimization. Moreover, an ANN approximation model was established with 64 experimental points generated by the D-optimal methodology. As a result, an aerodynamically optimized shape for the rear end of the sedan in which the aerodynamic performance is improved by about 5.64% when compared to the baseline vehicle is proposed. Finally, it is expected that within the accepted range of shape modifications for a rear body, the aerodynamic performance of a sedan can be enhanced so that the fuel efficiency of the sedan can be improved. The YF SONATA, a sedan manufactured by Hyundai Motors Corporate, played a major role in this research as the baseline vehicle.     

集装箱船线型优化研究

为了充实船型数据库及满足将来可能的市场需求,结合传统经验设计方法和CFD技术同步进行了集装箱船的线型研发。通过两个方案的船模试验结果的比较,得出一些有意义的结论,对将来的线型设计工作具有一定的启迪意义。     

海洋作业工程船空调设计

随着海上石油勘采、矿产资源开发的日益升温,海洋作业工程船是近几年市场需求量较大的一类船型,由于船员配置及作业环境的特殊性,空调系统的设置同常规船舶相比有其特殊的要求。同时随着造船技术的发展,人们对船舶空调系统的舒适性、经济性的要求也越来越高。该文通过4 000 t全回转起重打捞工程船空调系统设计,对此类工程作业船舶空调设计方面的一些问题进行论述,可供读者参考。     

VW-MSPC方法在变压器状态评估中的应用研究

针对变压器状态评估变量指标之间具有相关性以及重要性不同的特点,在基于马氏距离的传统多元统计控制图中引入加权马氏距离,设计一种基于变量加权的多元统计过程控制的变压器评估方法。该方法结合关联规则方法给出的变压器关键指标变量体系利用多元控制图的波动检出能力,将变压器各类故障对应的多元实时监测数据转化为一个检验统计量,进而对变压器运行状态进行评估。电流回路过热故障的实例分析表明,相对于现行的变压器状态评估标准,该方法具有更快的故障检出速度;对于已知故障的样本数据的回顾检测表明该方法具有较高的故障检出率。     

Collision avoidance path planning in multi-ship encounter situations

Journal of Marine Science and Technology - Collision avoidance path planning is still one of the essential problems in the design and application of an intelligent maritime navigation system. Its...     

120m内河邮轮线型设计与试验

运用CFD数值模拟技术和模型试验相结合的方法,优化设计豪华邮轮线型和螺旋桨,模型试验和空泡激振力试验表明,设计的船型阻力低,推进效率优良,设计桨空泡性能优良,诱导激振力非常小,使船舶的经济性和舒适性得到了保证。