流态粉煤灰室内试验研究

从流动性和力学性能两个角度研究了水泥掺量、用水量、养护环境对流态粉煤灰性能的影响;设计出适应于流态粉煤灰的CLSM材料流动性试验方法及评价指标;结果表明,流态粉煤灰流动性随水泥掺量影响不大,与用水量成正比,并存在最佳用水量点。流态粉煤灰强度与水灰比成正比,养护环境对流态粉煤灰强度发展影响较大。     

某国IV柴油机催化器流场分析

为分析某国IV柴油机后处理装置内部流场的气流分布,文章通过CFD软件AVL-FIRE对该柴油机的催化器进行了CFD仿真分析,计算得到了催化器载体DOC和POC前端的速度均匀性系数,该结果符合评价标准。结果表明,裁体前端的速度均匀性系数均处在一个较高的水平,能够满足气流分布均匀性要求。     

计算流体力学方法在船舶领域的实用性研究

通过CFD（计算流体力学）方法对船舶领域两个典型的工程实例进行了数值计算和流场模拟,模拟的流场与船池试验的流场很吻合。数值计算结果和试验值比较,在特定n范围内相对误差在6．6％以内,满足工程要求。表明数值方法在船舶航速预报方面具有一定的工程实用性,以CFD计算结果为依据光顺流场流线优化船舶阻力性能的可行性也得到工程实例证明。     

Directional performance issues in evaluation and design of articulated heavy vehicles

This review of the dynamics of heavy road-vehicle systems emphasizes directional performance. The review presents information on the following topics: why are articulated vehicles used; units, hitches, and combination vehicles; multiple axle suspensions and steering systems; important performance issues; models and simulation tools; and controlling directional performance. The concluding section summarizes the material presented and provides ideas regarding the application of vehicle system dynamics concepts in developing controllers for road trains.     

振动钻削时钻头的动力学模型

为了给振动钻削的进一步发展提供有力的理论依据，根据欧拉－伯努利梁理论并用哈密顿原理，建立了振动钻削时钻头的动力学模型。该模型包括了钻头以及钻削操作的重要特性，即钻头的截面几何特征、螺旋角、转速和钻削过程中产生的切削力。     

考虑塑性变形的振动压路机非线性动力学仿真

借助于土壤变形的一种塑性模式，提出了一种振动压路机压实过程的非线性动力学模型。在此基础上，借助计算机技术，探讨了振动压实中机架与振动轮的运动规律，并对激振力减少、土壤刚度变大和塑性变形增大等情况进行了仿真研究，发现了一些对压路机设计有参考价值的新现象     

A simplified model of wheel/rail contact mechanics for non-Hertzian problems and its application in rail vehicle dynamic simulations

The presented model assumes semi-elliptical normal pressure distribution in the direction of rolling. The contact area is found by virtual penetration of wheel and rail. The normal pressure is calculated by satisfying contact conditions at the geometrical point of contact. The calculation is non-iterative, fast and completely reliable. It may be carried out on-line in MultiBody Systems (MBS) computer codes. The tests using the programme CONTACT by Kalker and experience from application in MBS codes show that the model is suitable for technical applications. The creep forces have been calculated with the FASTSIM algorithm, adapted for a non-elliptical contact area. Some applications in rail vehicle dynamics and wear simulation have been outlined.     

基于CFD方法的6500TEU集装箱船舵空泡腐蚀数值模拟研究

舵的空泡腐蚀研究在船型优化设计和新船型开发中具有重要意义。文章以6 500 TEU集装箱船的NACA0021舵为研究对象,通过对船、桨、舵整体三维建模,运用CFD方法在3D计算域下对舵的非定常空化现象进行数值模拟,得到了与试验比较一致的结果。同时还对改善舵空蚀现象的措施进行了分析。研究表明,通过整体建模的数值模拟方法对舵空泡性能进行预测研究,其结果是合理可信的。     

流场控制体对喷水推进器性能预报影响的研究

为准确预报喷水推进器设计工况与非设计工况的水动力性能,采用CFD方法对喷水推进器性能预报所需流场控制体进行了研究.在验证计算方法和数值模型可信的基础上,通过对比不同流场控制体的计算结果,分析了流场控制体对喷水推进器性能预报的影响.首先,确定了设计工况下流场控制体的大小;然后,对非设计工况下流场控制体的选取进行了分析讨论.结果表明,非设计工况下流场控制体的大小对喷水推进器性能预报的影响比设计工况大,而且非设计工况下所需流场控制体要大于设计工况时的情况.     

Dynamics Performance of Subgrade-Tunnel Transition on Chongqing-Suining Ballastless Track

Experiments were conducted on China railway high speed electrical multiple units (EMUs) CRH2 and freight car C80 on Chongqing-Suining high-speed ballastless track. Based on the experimental results, the dynamics performance of cement concrete transition and cement stabilized aggregate transition was analyzed. The results show that the dynamic stress, vibration displacement, vibration velocity, vibration acceleration and other vibration parameters vary steadily on the profile section of transitions, and that at the adjoining position between subgrade and tunnel portal, cement concrete transition has gradual hardness change, whereas cement stabilized aggregate transition exhibits good elasticity, small shock, and small dynamic effect of the cars.