Estimation of Design Wave Heights for Coastal Sea Areas

Based on historical wind fields in the Bohai Sea, a sequence of annual extremal wave heights is produced with numerical wave models for deep-water and shallow water. The design wave heights with different return periods for the nearest deep-water point and for the shallow water point are estimated on the basis of P-III type, Weibull distribution, and Gumbel distribution; and the corresponding values for the shallow water point are also estimated based on the HISWA model with the input of design wave heights for the nearest deep-water point. Comparisons between design wave heights for the shallow water point estimated on the basis of both distribution functions are HISWA model show that the results from different distribution functions scatter considerably, and influenced strongly by return periods; however, the results from the HISWA model are convergent, that is, the influence of the design wave heights estimated with different distribution functions for deep water is weakened, and the estimated values decrease for long return periods and increase for short return periods. Therefore, the numerical wave model gives a more stable result in shallow water design wave estimation because of the consideration of the effect of physical processes which occur in shallow water.

Offshore Design Waves for Dayaowan Port Area of Dalian Port

This paper introduces the calculating procedure of the offshore design waves for the Dayaowan port area of Dalian Port. Some suggestions are proposed about the conventional calculating methods with measured waves data.

Discussion on the parameters of design waves

为了在设计上回答耻辱，挥动标准并且挥动参数在设计上推荐新考虑，基于波浪的统计特征和给回来时期定义的海状态的短期的概率性质的长期的分发，回来时期的计算，高度，时期，和设计波浪和预报方法的海洋的波浪参数在这篇论文被讨论。为了在极端海为漂浮的结构的操作可靠性提供参考书，说，决定设计波浪参数的方法是 resurveyed。一个建议被推荐设计波浪，它能是也重要的波浪与回来时期，或有超过概率的 1/N 的最大的波浪 500 年，回来时期 100 年，能在设计设计实践被使用。

基于NX/WAVE技术的内燃机并行设计的应用研究

目前,大多数设计研发类公司进行自顶向下设计时,常采用Siemens NX软件中的WAVE技术来缩短研发周期,提高团队工作效率和增强企业竞争力。该技术在复杂的关键零部件如变速器、曲轴箱、曲轴和连杆等的设计中应用较为常见,而在内燃机整机设计中应用较少。以某中置卧式直列双缸摩托车发动机为研究对象,采用NX/WAVE技术对发动机整机进行并行设计。

Hydraulic Design Method of Wave Dissipating Structure with Partially Perforated Front Wall

Based on the matching conditions of different fluid regions, the eigenfunction expansion method is used to develop a theoretical formula for wave reflection in front of the perforated structure with a partially slit front wall. The accuracy of the solution is verified by comparing the numerical results with experimental data. In addition, a new hydraulic design method is developed by derivation of the theoretical formula with respect to the porosity of the slit wall, and the results of this design method is drafted for harbour engineers to use.

Structural Design and Protective Methods for the 100 kW Shoreline Wave Power Station

The structural design and protective methods for the 100 kW shoreline wave power station in China are described in detail. The proper structural type is designed for effective minimization of wave loads and bending stress. Various protective devices are adopted to protect the station in the extreme conditions against excessive power of airflow, excessive torsion of the shaft, over-pressure of the chamber, over-speed of rotation, power failure, and so on. It turns out that the structural design and protective methods for the 100 kW shoreline wave power station are successful.

Design of Distorted Wave Protection Armor Units

In consideration of the global optimization for engineering projects, a group of calculation formulas have been derived by means of theoretical derivation and model tests. On this basis, a design procedure for the distorted units is proposed, by means of which the distorted units of an anology shape and an identical porosity ratio with the original units can be obtained after conducting a distorted enlargement and a normal contraction. The stability waveheight and stability factor of the distorted unit can be calculated with the enlargement factor, a, of the horizontal dimension of the distorted unit, or with the contraction scale, A , of the contracted distorted unit. As a result, the stability of the armor unit can be significantly improved without increasing the quantity of concrete. For the same wave met by the original units, the thickness of placement of the contracted distorted unit can be obviously reduced, thus, a large quantity of concrete can be saved, consequently, economic benefit can be achieved.

A Novel Beam Design Method for mm Wave Multi-Antenna Arrays with Mutual Coupling Reduction

To overcome the mutual coupling (MC) of multiple antennas in millimeter wave (mmWave) communication systems, a novel beam design method with low complexity is proposed in this paper. Firstly, an equivalent channel model incorporating the effect of MC is analyzed and established, and then an optimal precoding / combiner vector for beamforming is derived. On this basis, by using greedy geometric (GG) algorithm, a novel hybrid beam design method is proposed. Finally, the performance of proposed method is analyzed and compared with other traditional ones. The simulation results show that the proposed method has better suppression of the MC effect as well as lower complexity.

Design and Experiment for Exhaust Pipes of Pressure Wave Supercharged Diesel Engine

NOx and soot emissions from diesel engines can be greatly reduced by pressure wave supercharging(PWS).The diesel engine matched with PWS needs redesigning its exhaust pipes.Except for meeting the installation requirements,the exhaust gas must be stable in pressure before rushing into PWS.In this paper the lateral and center ported divergent exhaust pipes are designed,modeled geometrically and analyzed structurally based on a 3-D design software-CATIA to determine the structure of two exhaust pipes having the required inner volume.Then flow analysis for two exhaust pipes is done using a flow analysis software-ANASYS.Moreover,the optimal exhaust pipes are determined comprehensively and cast for engine test.Engine test results show that PWS is superior to turbocharging at low engine speeds and inferior to turbocharging in power and emissions at medium-to-high engine speeds.The performance of PWS engine under high speed operating conditions can be improved by contriving larger surge volume intake and exhaust pipes.

10 MW级海上风电新型浮式基础结构强度分析

针对应用于50 m水深海域的10 MW海上风力机,设计由三浮筒及三立柱组成的新型浮式基础,建立带有骨材结构的有限元分析模型。对于有关此新型浮式基础的设计波参数,一般选用随机性设计波的方法来确定,对波浪载荷工况下的整体结构。重点研究浮筒的骨材尺寸以及骨材间距对新型浮式基础强度的影响规律,并得到纵横骨材尺寸组合对新型浮式基础整体强度的影响规律。研究表明,新型浮式基础结构高应力区域位于3个浮筒连接处,浮筒板单元应力水平受骨材尺寸和骨材间距的共同影响,采用合适的尺寸间距组合可在应力水平相当的情况下显著降低用钢量。

基于波峰焊桥连改善的设计优化研究

波峰焊是一种常见的电装工艺焊接方式,而桥连是波峰焊工艺最为常见的焊接缺陷之一。介绍了波峰焊接桥连产生的机理,并分析了焊盘间距过近、引脚出脚长度过长,以及器件布局方向不当三种典型可制造性设计引起桥连的原因,并探讨了有助于波峰焊接桥连改善的可制造性设计优化方案。

基于MIMO阵列的一体化射频技术研究进展及展望

基于多输入多输出(multiple-input-multiple-output,MIMO)阵列的一体化射频系统通过充分利用空间自由度和波形自由度,不仅能够同时实现雷达探测、数据通信、电子干扰等多种功能,而且具有目标探测可靠性好、参数估计精确度高、反侦察识别能力强等突出特点,在高动态强对抗环境中展现了巨大的潜力。从基于MIMO阵列的一体化射频系统的检测性能分析入手,剖析了一体化射频系统的检测性能极限以及影响检测性能的主要因素;针对MIMO阵列参数高精度估计问题,提出通过单个发射脉冲完成参数估计以及一种增强参数估计精度的波形优化算法;考虑到目标角度估计误差不可避免,提出了一种稳健的一体化波形设计算法;针对杂波环境中一体化射频系统性能下降的问题,提出了发射波形和接收滤波器联合优化算法,该算法不仅能够实现同时多功能,而且有效地抑制了杂波,提高了目标检测性能。最后,展望了一体化射频系统参数估计精度极限、高精度参数估计、稳健波形设计、波形设计算法快速实现等有待突破的信号处理关键技术。

圆筒型FPSO总体强度校核设计波优化算法

针对圆筒型FPSO总体结构强度准静态设计方法依赖工程师经验的局限性,将设计波法引入圆筒型FPSO总体结构强度校核,提出了针对特征荷载选择的优化算法。该方法通过分析圆筒型FPSO总体结构承载特点和失效模式,结合常用特征载荷中有相同设计波的特征荷载,选择了舷侧外板波浪压力、上部模块重心处的水平和垂向加速度,作为设计波筛选的特征载荷;并根据圆筒型FPSO结构对称性,减少加载浪向,优化设计波搜索相位;基于本文方法的校核工况减少了60%,有效提升了校核效率。该方法已被应用于中国首条完全自主设计的圆筒型FPSO“海洋石油122”平台的强度校核中,校核结果通过了挪威船级社认证,该平台目前已完成设计,进入建造阶段,这也说明了本方法的可行性以及对后续同类FPSO设计的借鉴意义。

WAVE技术及其在自顶向下设计中的应用研究

研究了UG WAVE技术及其内涵,以汽车后桥为例,探讨了利用该技术建立自顶向下的产品设计模型的方法。

“电波与天线”课程思政探索与实践

深入推进课程思政教学的研究和实践,是高校立德树人的重要任务之一。“电波与天线”是电子信息工程技术专业的一门专业课,这门课在课程思政教学改革的探索与实践中,主要针对思政元素的挖掘、课程思政的具体实施、课后思政效果的评价等方面进行了研究,并通过充实原有教材、优化教学大纲、创新教学方法、改进评价体系、健全反馈机制等手段,进行教学实践。实践表明,采用课程思政教学改革的班级在教学效果上优于传统的班级。

基于CFD仿真的炮口制退器性能影响因素研究

目的 在降低火炮后坐力的同时,保证炮手区域超压和温度符合要求。方法 利用流体仿真软件进行炮口流场的数值模拟,对制退器性能影响因素进行仿真分析。根据分析结果,得到改进后的制退器模型,并进行仿真和试验对比。结果 加装侧孔外反射挡板和侧孔倾斜对制退器性能的影响较大,并随角度的变化而变化,加装吹孔能有效降低炮后超压和温度。改进后,制退器的效率提升8.33%,炮后超压值平均降低44.10 kPa,炮后温度值平均降低358.28 K。结论 改进后的制退器具有更高的制退效率以及较低的炮后超压值和温度值。

舰船环境适应性设计方法探索与实践

探索舰船环境适应性的设计方法,以提高舰船在各种复杂环境下的适应能力。分析了舰船环境适应性设计中面临的若干问题和改进提高方向,参考借鉴国内外航空航天、电子等行业成功经验,提出了指导舰船环境适应性设计的主要设计原则和工作内容。围绕改善环境条件、加强耐环境能力设计这2个方面,提出了3种环境适应性设计方法,包括基于规范的设计方法、基于环境仿真的设计方法、基于预使用验证的设计方法。根据舰船风浪环境适应性设计的特点和要求,选择采用环境仿真和模型试验技术开展了应用研究。基于分析结果,提出了增加水线面系数、调整浮心、优化线型等多项改进措施建议。采用环境仿真和模型试验相结合的方式,可有效支撑舰船风浪环境适应性设计和评估,这一方法具有较高的工程推广应用价值。另外,未来应加大环境仿真技术的研究和应用力度,尝试开展多因素综合环境仿真,以进一步提高舰船的环境适应性。

短波红外成像系统设计及应用的研究进展

短波红外光学成像是目前国际上研究热点之一,通过接收短波红外辐射进行探测和成像,可得到更多目标物体的信息,弥补了可见光成像的不足,从而实现全波段成像。本文从短波红外光学成像的光学特性、成像原理和光学系统结构设计出发,比较了短波红外与可见光和中长波红外成像的优缺点,并简单介绍了短波红外成像系统中铟镓砷探测器的特点和国内外发展现状,以及介绍了短波红外成像在不同领域的应用情况,最后,对短波红外成像未来的发展进行了展望。