A study on improving the course-keeping ability of a pure car carrier in windy conditions

The course-keeping ability of a pure car carrier (PCC) in windy conditions is discussed in this article. Numerical simulations of two PCCs were carried out to compare their course-keeping abilities in wind. The two PCCs had the same hull form but different types of rudder. One PCC was fitted with a semispade rudder (hereinafter, the normal rudder), whereas the other was fitted with a spade-type Schilling rudder (hereinafter, the Schilling rudder). Both PCCs were designed to a new concept for the accommodation structure and hull form above the load water line. In this new design concept, there are no sharp corners in the superstructure so as to reduce wind resistance and improve steering performance. The limits of course keeping for the two PCCs were investigated through simulations. The course-keeping abilities of the two PCCs, each with two different types of autopilot system, were also investigated in wind. To develop the numerical simulation, the hydrodynamic coefficients of the two PCCs were predicted based on the data published for a third PCC having similar principal particulars. The numerical model of the two PCCs was validated by comparing its behavior with the respective full-scale trial results. Wind resistance coefficients were predicted by combining the results of wind tunnel experiments of the object PCCs and a regression model. Numerical simulations under steady wind conditions were also carried out and the results compared with some full-scale experiments to validate the mathematical model of the PCC.     

全风向梯度集沙仪的研制

兰新铁路风区防风沙工程的建设对保证列车风区安全行驶至关重要,而掌握风沙流规律是防沙工程设计的基础,为此,根据历史大风特征统计分析结果研制了全风向梯度集沙仪,对风沙流进行现场观测。全风向梯度集沙仪为兰新铁路第二双线防沙减灾工程的建设提供了基础数据依据。     

优化JT6120型客车气动特性的风洞试验

对影响ＪＴ６１２０型客车气动特性的主要外形结构参数进行了系列风洞试验，并对整车气动特性进行了优化，获得了最优化形设计方案，其空气阻力系数由０．７１下降至０．３４，其它气动特性指标也得到相应改善。     

高速铁路接触网风致振动与风偏的动态计算方法

利用ANSYS软件建立接触网弹链、简链风致响应有限元模型,从导线弛度、张力及弹性角度,验证有限元模型的准确性;采用谐波合成法(WAWS)模拟针对接触网结构特点的脉动风场;计算系统在风荷载作用下的动态响应,利用空气动力学理论计算接触网平均位移,采用时程分析方法计算接触网动态位移,并将二者叠加得到接触网风致响应总位移。通过开展接触网气动弹性风洞试验,结果表明:提出的基于有限元的风致振动与风偏的动态计算方法与风洞试验结果基本吻合;该方法计算结果准确,具有较好的工程应用价值。     

风力发电机组远程监控及风场风机管理软件的开发

为使风电机组可靠运行、高效发电及便于管理,开发了风机远程控制及风电场管理软件。该软件采用WINDOWS操作系统下的VC++加后台关系数据库、C/S(客户端\服务器)体系结构、多线程数据联系方式,界面友好,使用方便,现场运行可靠。文章描述了该软件数据库中风机特性表和数据处理表,介绍了其数据通信及处理模块等主要模块及部分关键技术。     

高原用兆瓦级风电机组电气系统的改进设计

分析了高原气候对兆瓦级风力发电机组电气系统的影响,以WT1650型变速恒频双馈异步风力发电机组(1.65 MW)为例,提出了该风电机组在海拔4 000 m环境条件下运行的解决方案,并对其电气系统做了改进设计,整个改进方案对常规风电机组在高原环境下运行有良好的指导作用。     

水泥石灰稳定风积砂作为路面基层材料的试验研究

采用均匀设计的方法来优化安排试验,以水泥、石灰、碎石、风积砂为原材料进行试验研究,得到水泥石灰稳定风积砂的最佳含水量、最大干密度、无侧限抗压强度、回弹模量等指标,并通过SPSS软件进行回归分析,建立了回归方程,得到满足工程要求的最佳配合比为:水泥掺量9%、石灰掺量10%、碎石掺量30%、风积砂掺量53%。通过现场工业性试验和观测,结果表明,试验段水泥石灰稳定风积砂基层状况良好,且弯沉值满足有关的要求。     

Strain estimation for offshore wind turbines with jacket substructures using dual-band modal expansion

Structural fatigue is a design driver for offshore wind turbines (OWT). In particular, the substructures, like jackets, are strongly affected by fatigue. Monitoring the fatigue progression in the welds is vital for the maintenance and a potential lifetime extension. However, inspections of critical locations are costly due to the limited accessibility of the mostly submerged jacket. Considering the high number of potentially critical welds, it is regarded as economically unfeasible to equip all fatigue hot spots with sensors. Thus, an indirect method to monitor the fatigue progress of the structure and point out critical locations is desirable. For a consistent support of ongoing maintenance, it has to yield reliable results for varying operational and environmental conditions. This paper applies a virtual sensing approach to jacket substructures. From a small set of sensors on the tower, fatigue at every desired location of the jacket is estimated using dual-band modal expansion. Simulations using the OC4 jacket design are performed to show potentials and limitations of the method. Namely fatigue progress on leg welds of K-joints is predicted with high accuracy over a wide range of load cases. However, some difficulties in fatigue prediction of X-joints due to the occurrence of local modes and limitations in the extrapolation of wave loading have to be resolved in future work.     

接触网参数对接触网风致响应的影响及风洞试验验证

大风作用会使接触网发生更大更复杂的振动与风偏,为给大风区接触网的防风设计提供科学依据,采用有限元计算与风洞试验相结合的方法进行研究。利用ANSYS软件建立包括支撑结构和悬挂部分的有限元耦合模型;采用谐波合成法(WAWS)模拟针对接触网结构特点的脉动风场;通过计算不同接触网参数组合方案在风荷载下的风致响应位移,定量分析得出悬挂类型、张力组合、跨距对接触网风致响应的影响。接触网气动弹性风洞试验结果表明,接触网参数对风致响应的影响的研究结果正确。研究成果应用于兰新铁路第二双线大风区接触网系统方案设计和技术参数选择,并作为主要理论支撑之一,形成了首个国内外铁路电化行业的风区接触网装备技术条件。     

舰用燃气轮机RMS参数体系研究

根据舰用燃气轮机的任务需求和使用环境特点,综合RMS参数体系需要考虑的因素,按定量参数和定性要求,提出了舰用燃气轮机RMS参数体系,并给出了定量参数的含义以及计算公式.