基于广义模块化快速设计的液压机产品模块划分与规划

提出柔性元结构和虚拟柔性模块的概念,通过对液压机产品进行模块的划分与规划,得到以柔性元结构为单位的结构单元,给出了液压机产品模块划分和规划的过程模型及应用实例,为实现液压机产品的快速设计提供支持。

颗粒粘结高燃速推进剂燃速设计方法的研究(英文)

介绍了颗粒粘结高燃速固体推进剂的工艺特点 ,利用推进剂燃烧特征化学基团方法预估了几种小药粒和速燃粘结剂的燃速 。

基于Pro／MOLDESIGN及NC的不规则破孔壳体件塑料模成型零件快速设计与制造

应用Pro／MOLDESIGN和NC模块实现了不规则破孔壳体件塑料模具成型．零件的快速设计与制造，从而缩短模具开发周期，降低开发成本。开模仿真结果验证了模具设计的合理性。

道路控速设计研究

超速行驶是道路交通事故的重要诱因之一。提出点车速和线车速的研究理念,分析其与交通安全的关系,在此基础上对减速标志标线和减速带的减速机理及特征进行研究,并结合驾驶员心理效应提出控速措施,最后对减速带横断面轮廓曲线进行了较为详细的设计研究,可为道路设计和管理部门提供相关理论依据与可行方法。

“速读—体悟—设计”式英语读后续写的实践样态

针对学生在读后续写过程中暴露出来的主题意义探究不准、续写情节表达失当和逻辑衔接不够合理等问题,提出“速读—体悟—设计”三步式读后续写教学思路。速读,以主人公的活动为线索,以时空变化为依托,迅速理解故事情节;体悟,分析感悟文本的语言特点和蕴含的主题意义;设计,依据故事发展逻辑,紧扣主题意义,用贴合原文的语言风格构思后续故事。

“速”与“慢”——有关“速食时代”设计观念的辩证思索

当下的设计已经走入了“速食化”的时代，伴随着中国巨龙经济的腾飞，中国设计市场势必引领全球的设计风向。但是，在面对设计是该遵循“速设计”还是该选择“慢设计”时，设计人仍面临着困惑。此文从辩证和发展的角度对“速食化设计”和“慢设计”进行对比、分析。进而对未来中国更适合何种设计理念做出有益的讨论。

面向高超声速飞行器的宽速域翼型优化设计

宽速域气动设计是水平起降高超声速飞行器研制的瓶颈问题之一。水平起降高超声速飞行器在飞行过程中需要经历亚、跨、超和高超声速多个速域,而适应不同速域的最佳气动外形相互矛盾,使得实现良好的宽速域气动设计面临极大挑战。首先,针对高超声速飞行器宽速域翼型气动设计问题,发展了基于代理模型的高效全局气动优化设计方法,并设计出一种相对厚度为4%、有一定弯度、下表面具有双“S”形特征的宽速域翼型。将新翼型与常规四边形和双弧形翼型进行了气动特性对比,并进行了流动机理分析,结果表明新翼型的宽速域综合气动特性显著优于常规翼型,从而证明发展兼顾亚、跨、超和高超声速气动性能的宽速域翼型是可行的。其次,开展了宽速域翼型的多目标优化设计,通过分析Pareto解集中翼型的宽速域气动性能随几何外形变化的演化规律,进一步解释了有一定弯度、下表面呈双“S”形的薄翼型能够协调亚、跨、超声速与高超声速气动性能的原理。最后,采用平面外形为梯形的机翼,进行了三维机翼构型下的宽速域翼型多目标优化设计。三维优化设计结果与二维结果具有相似的几何特征和压力分布,说明这种通过下表面双“S”形小弯度薄翼型来兼顾亚、跨、超和高超声速气动性能的宽速域流动机理同样适用于三维情况,也证实了翼型设计对于宽速域高超声速飞行器仍然具有重要意义。

延迟焦化装置焦炭塔适宜设计气速探讨

结合延迟焦化装置实际,利用工程中的物料输送模型计算了延迟焦化装置焦炭塔设计的最大允许气速并分析了影响设计气速的因素。同时提出:模型中修正系数最终确定应根据不同的原料并有大量的实验数据作为支撑,如果知道进行焦化反应的焦炭塔中焦粉和中间相液滴的粒度分布,就可应用微分方法计算出焦炭塔气速和焦粉夹带量的关系。运用该模型分析和计算焦炭塔最大允许气速对焦炭塔的工艺设计具有一定的现实意义。

绿色环保下服装设计发展的趋势分析

随着环境问题日益突出,其对社会文明发展的制约效应日益明显,促使人们环保意识的觉醒,人们愈加追求低碳环保的绿色生活方式。在这种情况下,催生了绿色设计理念,它是基于绿色环保思想产生的一种与时俱进的设计理念,目前已经融入服装设计领域,备受各国设计师推崇。在这里,本文从绿色环保与服装设计的关系入手,分析了绿色服装设计理念的发展背景与条件,然后提出了绿色服装设计的基本内涵、特点,最后对绿色服装设计下的有机设计、再生设计、慢速设计进行了探讨,以阐明绿色环保下服装设计发展的趋势。

运输类飞机适航标准中的速度研究及应用

飞机的各种速度与飞行安全密切相关,关系到飞机的飞行性能、飞行品质、强度和飞行导航等方面。CCAR-25-R4中规定了一系列以不同类型表示的、在飞机的设计过程中必须制定的飞机设计和使用速度。速度类型和名称不同,含义和用途不同。如安全起飞速度V_2和基准失速速度V_(SR)用于保证飞机安全起飞和稳定飞行;飞机设计巡航速度V_C和设计机动速度V_A用于保证规定飞行条件下飞机的强度。本文对CCAR-25-R4中的主要速度进行了系统研究,给出了基本速度类型、各失速速度、起降速度、设计空速和限制速度的含义和相互关系,还给出了两个型号中V_C和V_D余量设计和使用速度舱内显示实例。

给水泵汽轮机速关阀的分析和改造

将使用低压透平油的液压调节系统改为使用高压抗燃油的纯电调系统可以提高控制品质,是汽轮机控制技术发展的趋势。通过对给水泵汽轮机速关阀的结构和工作原理的分析,论述了速关阀改造的必要性和可行性;并对主要部件进行了设计计算,完成了速关阀改造的设计方案。

Parallel rapid relaxation inversion of 3D magnetotelluric data

We implement a parallel algorithm with the advantage of MPI （Message Passing Interface） to speed up the rapid relaxation inversion for 3D magnetotelluric data. We test the parallel rapid relaxation algorithm with synthetic and real data. The execution efficiency of the algorithm for several different situations is also compared. The results indicate that the parallel rapid relaxation algorithm for 3D magnetotelluric inversion is effective. This parallel algorithm implemented on a common PC promotes the practical application of 3D magnetotelluric inversion and can be suitable for the other geophysical 3D modeling and inversion.

Effect of process parameters on sheath forming of continuous extrusion sheathing of aluminum

The effect of flow passage length in the die cavity and extrusion wheel velocity on the shape of aluminum sheath during the continuous extrusion sheathing process was analyzed by using finite element methods based on software DEFORM 3D and experimentally validated. The results show that by increasing the flow passage length, the velocity of metal at the cross-section of sheath tends toward uniformity, the values of the bending angles of sheath gradually approach the ideal value of zero and the cross-section exhibits a better shape. The extrusion wheel velocity has negligible effects on the bending shape and cross-section of the sheath product when a long flow passage is used.

Herrmann Method of Analyzing Structure Design Velocity Field

The shape optimization is studied by adopting the domain integrated method which is based on the calculus of variations during the shape design sensitivity analysis. A new method of improving the efficiency of the design velocity field analysis and the quality of the finite element method (FEM) mesh is put forward. The sensitivity analysis which is based on the calculus of variations is used in the shape optimization. The design velocity field is solved by Herrmann method. An example shows that both the quality of the FEM mesh and the efficiency of the computing of the design velocity field are improved by Herrmann method. So the effect and the efficiency of the shape optimization are guaranteed. If using sensitivity analysis which is based on the calculus of variations in the shape optimization, the sensitivity analysis can be a relatively independent module. The efficiency of computing the design velocity field and the quality of mesh will be improved by using Herrmann method.

Oil-Film Clutch in Soft-Start of Belt Conveyor

The oil film clutch, which is superior in speed adjustment, is capable of being used in the belt conveyor to carry out soft start operation. According to running properties of both belt conveyor and oil film clutch, equations that are used to decide the lubricating oil flow and the number of oil films (i.e. the number of rotating and stationary plates) are deduced theoretically. Also key parameters are provided for the design of the hydraulic system. All these together provide the theoretical basis for the soft start design of the belt conveyor and references for the application of the oil film clutch in similar fields.

空天飞行器机翼/翼型的需求分析及应用

空天飞行器飞行空域大,速域宽,经历亚/跨/超/高超声速飞行,气动特性变化大,传统翼型难以同时满足低速、高速时的设计要求,给机翼/翼型设计提出了新的挑战。本文围绕飞行环境特点,分析了低速高升力与高速高升阻比、升重匹配、结构热防护等设计要求,提出了空天飞行器对机翼/翼型设计的新需求。基于一种新的宽速域翼型,采用数值模拟方法,开展三维流动下翼型与机翼平面形状的一体化优化设计,获得了一种翼型沿展向变化的新机翼,相对优化前,低速时机翼产生的升力效率提高了36.3%,超声速和高超声速升重平衡升阻比分别提高了33.4%和12.9%,新机翼能更好地兼顾低速、跨声速、超声速和高超声速气动性能的要求。将新机翼应用于典型空天飞行器,再通过全机气动外形优化设计,进一步提高了宽速域飞行时升重平衡下的使用升阻比,高亚声速时提高了5.9%,超声速时提高了10.3%,高超声速时提高了0.7%,解决了低速飞行时高升力与高速飞行时高升阻比的需求矛盾,并获得了一种满足宽速域总体设计要求的空天飞行器气动布局。研究成果具有一定工程指导意义。

Design of an optimal active stabilizer mechanism for enhancing vehicle rolling resistance

Improving rollover and stability of the vehicles is the indispensable part of automotive research to prevent vehicle rollover and crashes.The main objective of this work is to develop active control mechanism based on fuzzy logic controller(FLC) and linear quadratic regulator(LQR) for improving vehicle path following,roll and handling performances simultaneously.3-DOF vehicle model including yaw rate,lateral velocity(lateral dynamic) and roll angle(roll dynamic) were developed.The controller produces optimal moment to increase stability and roll margin of vehicle by receiving the steering angle as an input and vehicle variables as a feedback signal.The effectiveness of proposed controller and vehicle model were evaluated during fishhook and single lane-change maneuvers.Simulation results demonstrate that in both cases(FLC and LQR controllers) by reducing roll angle,lateral acceleration and side slip angles remain under 0.6g and 4° during maneuver,which ensures vehicle stability and handling properties.Finally,the sensitivity and robustness analysis of developed controller for varying longitudinal speeds were investigated.

Design and dynamic simulation of hydraulic system of a new automatic transmission

A new hydraulic system of a novel automatic transmission (AT) was designed. The dimension and structure of valves and cylinders were designed by theoretical calculation. The dynamic simulation model of hydraulic system of AT was established by ITI-SimulationX. Simulation results and theoretical design results were compared to confirm the simulation model. Based on the confirmed simulation model, the simulation results of pressure and flow of the hydraulic system were analyzed. The dynamic simulation method is very helpful for designing and analyzing the performance of hydraulic system and further optimization design. The theoretical design method and dynamic simulation model are feasible for the real industrial applications. The research results can be used in hydraulic system design and optimization.

Dynamic response limit of high-speed railway bridge under earthquake considering running safety performance of train

Due to the wide railway network and different characteristics of many earthquake zones in China,considering the running safety performance of trains(RSPT)in the design of high-speed railway bridge structures is very necessary.In this study,in order to provide the seismic design and evaluation measure of the bridge structure based on the RSPT,a calculation model of RSPT on bridge under earthquake was established,and the track surface response measure when the derailment coefficient reaches the limit value was calculated by referring to 15 commonly used ground motion(GM)intensity measures.Based on the coefficient of variation of the limit value obtained from multiple GM samples,the optimal measures were selected.Finally,the limit value of bridge seismic response based on RSPT with different train speeds and structural periods was determined.

Energy Efficient Multi-Antenna UAV-Enabled Mobile Relay

In this paper, we study an energy efficient multi-antenna unmanned aerial vehicle(UAV)-enabled half-duplex mobile relaying system under Rician fading channels. By assuming that the UAV follows a circular trajectory at fixed altitude and applying the decode-and-forward relaying strategy, we maximize the energy efficiency by jointly designing beamforming, power allocation, circular radius and flight speed, subject to the sum transmit power constraint on source node and UAV relay node. First, we maximize the end-to-end signal-to-noise ratio by jointly designing beamforming and statistical power allocation. Based on the obtained beamforming and power allocation results, we then obtain a semi closed-form expression of energy efficiency, and finally maximize energy efficiency by optimizing flight speed and circular radius, allowing optimal circular radius to be obtained via numerical computation. Numerical results demonstrate that the proposed scheme can effectively enhance the system energy efficiency.