Bench Test Modeling for Current and Future PCMO Fuel Economy Requirements

The automotive and lubricant industries have been placing increased emphasis on the fuel economy benefits of today′s modern passenger car motor oils.The current ILSAC GF-4 specification has more stringent requirements than previous ILSAC specifications,and the proposed future ILSAC GF-5 specification is looking at further improvements in the lubricant′s fuel economy performance.To address these needs,Afton Chemical has developed correlations between the rheological and frictional properties of oils and fuel economy measured in engine and field tests.In this paper we will present correlations between lubricants′ physical properties and fuel economy measured in vehicles and engine tests.These tools have been used to develop current commercial oils which are being used extensively to meet today′s OEM needs.

In vitro bench testing using patient-specific 3D models for percutaneous pulmonary valve implantation with Venus P-valve

Background:Due to the wide variety of morphology,size,and dynamics,selecting an optimal valve size and location poses great difficulty in percutaneous pulmonary valve implantation(PPVI).This study aimed to report our experience with in vitro bench testing using patient-specific three-dimensional(3D)-printed models for planning PPVI with the Venus P-valve.Methods:Patient-specific 3D soft models were generated using PolyJet printing with a compliant synthetic material in 15 patients scheduled to undergo PPVI between July 2018 and July 2020 in Central China Fuwai Hospital of Zhengzhou University.Results:3D model bench testing altered treatment strategy in all patients(100%).One patient was referred for surgery because testing revealed that even the largest Venus P-valve would not anchor properly.In the remaining 14 patients,valve size and/or implantation location was altered to avoid valve migration and/or compression coronary artery.In four patients,it was decided to change the point anchoring because of inverted cone-shaped right ventricular outflow tract(RVOT)(n=2)or risk of compression coronary artery(n=2).Concerning sizing,we found that an oversize of 2-5 mm suffices.Anchoring of the valve was dictated by the flaring of the in-and outflow portion in the pulmonary artery.PPVI was successful in all 14 patients(absence of valve migration,no coronary compression,and none-to-mild residual pulmonary regurgitation[PR]).The diameter of the Venus P-valve in the 3D simulation group was significantly smaller than that of the conventional planning group(36[2]vs.32[4],Z=-3.77,P<0.001).Conclusions:In vitro testing indicated no need to oversize the Venus P-valve to the degree recommended by the balloon-sizing technique,as 2-5 mm sufficed.

Study of the Judder Characteristics of Friction Material for an Automobile Clutch and Test Verification

The friction judder characteristics during clutch engagement have a significant influence on the NVH of a driveline.In this research,the judder characteristics of automobile clutch friction materials and experimental verification are studied.First,considering the stick-slip phenomenon in the clutch engagement process,a detailed 9-degrees-of-freedom(DOF)model including the body,each cylinder of the engine,clutch and friction lining,torsional damper,transmission and other driveline parts is established,and the calculation formula of friction torque in the clutch engagement process is determined.Second,the influence of the friction gradient characteristics on the amplification or attenuation of the automobile friction judder is analyzed,and the corresponding stability analysis and the numerical simulation of different friction gradient values are carried out with MATLAB/Simulink software.Finally,judder bench test equipment and a corresponding damping test program are developed,and the relationship between the friction coefficient gradient characteristics and the system damping is analyzed.After a large number of tests,the evaluation basis of the test is determined.The research results show that the friction lining with negative gradient characteristics of the friction coefficient will have a judder signal.When the friction gradient value is less than-0.005 s/m,the judder signal of the measured clutch cannot be completely attenuated,and the judder phenomenon occurs.When the friction gradient is greater than-0.005 s/m,the judder signal can be significantly suppressed and the system connection tends to be stable.

Inertia Matching During Dynamic Simulation of Vehicle Drive System on Test Bench

Framework and basic parameters of a test bench for motor drive system of electric vehicle (EV) are illuminated. Two kinds of electric drive models, one was for the electric vehicle drived on real road, the other was for that on test bench, are put forward. Then, dynamic analysis of these models is made in detail. Inertia matching method of the test bench is researched and some useful formulas and graphs are brought forward. The experiment of an electric bus is introduced in order to explain the usage of this inertia matching method.

Electronic Unit Pump Test Bench Development and Pump Properties Research

A unit pump test bench is developed on an in-line pump test platform. The bench is composed of pump adapting assembly, fuel supply subsystem, lubricating subsystem and a control unit. A crank angle domain injection control method is given out and the control accuracy can be 0.1° crank degree. The bench can test both mechanical unit pump and electronic unit pump. A test model-PLD12 electronic unit pump is tested. Full pump delivery map and some influence factors test is done. Experimental results show that the injection quantity is linear with the delivery angle. The quantity change rate is 15% when fuel temperature increases 30 ℃. The delivery quantity per cycle increases 30 mg at 28 V drive voltage. The average delivery difference for two same type pumps is 5 %. Test results show that the bench can be used for unit pump verification.

Changes in coronary bifurcations after stent placement in the main vessel and balloon opening of stent cells:theory and practical verification on a bench-test model

Objective To describe changes that occur in stent morphology and structure after its implantation in coronary bifurcation.Side branch (SB) compromise after stenting of main vessel in coronary bifurcation is a major intraprocedural problem and for the long term,as a place of restenosis.Methods We created an elastic wall model (parent vessel diameter 3.5mm,daughter branches 3.5mm and 2.75mm)with 30,45 and 60 degree distal angulation between branches.After stent implantation,struts to the side branch were opened with 2.0mm and consequently 3.0mm diameter balloons.Subsequent balloon redilatations and kissing balloon inflations (KBI) were performed.All stages of the procedure were photographed with magnification up to 100 times.Results We found that the leading mechanism for side branch compromise was carina displacement,and discovered theoretical description for expected ostial stenosis severity.Based on our model we found that displacement of bifurcation flow divider cause SB stenosis with almost perfect coincidence with our theoretical predictions.Opening of stent cells through the proximal and distal stent struts always increased interslrut distance,but never achieved good apposition to the wall.Balloon diameter increase didn't give proportional enlargement in stent cell diameters.KBI leads to some small better stent positioning,correcting main vessel strut dislodgment from wall,but never gave full strut-wall contact.Distance between struts and wall was minimal only when the stent cell perfectly faced ostium of SB.This was also our observation that the shape of ostium of SB becomed eUiptically-bean shaped after stent implantation and generally kept that shape during consequent stages of experiment.Measured diameter and area stenosis were perfectly fitted and theoretically predicted from our concept Conclusion We have described stent-wall deformations in stent-balloon technique for treatment of coronary bifurcation demonstrating carina displacement as possibly main mechanism of side branch compromise after main vessel stenting.We have shown that KBI could not give full strut-wall contact if there is no perfect facing of stem cell and SB ostium.(J Geroatr Cardool 2008;5(1):43-49)

A versatile test bench for photomultiplier tube characterization and its application in the DAMPE-PSD

Performance characterization for massive photomultiplier tubes(PMTs) is a frequently encountered procedure in large nuclear and particle experiments.To facilitate this work,a dedicated test bench system has been developed at the Institute of Modern Physics,Chinese Academy of Sciences.The two-dimensional photocathode position scanning capability is an intrinsic function of the test bench,and up to 25 PMTs,with the diameter smaller than 2",can be tested simultaneously.The parameters of the light source pulses can be adjusted in a wide range,thus making it suitable for various characteristics measurements.The test bench system is highly automated with all the controlling operations integrated into a single software.Additionally,the hardware platform is extensible which allows complex testing schemes,and the modularity in the software design makes the migration from one testing configuration to another light-weight and efficient.All these features make the test bench versatile and reusable in different experiments.It has been first used in the construction of the Plastic Scintillator Detector(PSD) of DArk Matter Particle Explorer(DAMPE),and a total of 570 Hamamatsu R4443 tubes were tested successfully.The performance was verified and the testing results are also reported in this article.

The Efficiency Improving of Traction Drive Test Bench with Supercapacitor Energy Storage System

For development of passenger electrical transport, it is necessary to use energy more rationally. One of methods of vehicle power efficiency increase is installation of on-board energy storage systems. For studying of system operation, it is necessary to carry out a lot of experiments, therefore it is favorable to use the test bench and its computer model for reduction of the number of physical experiments. In this article, the results of computer modeling for the optimization of traction drive test bench by adjusting of the operation parameters of supercapacitor energy storage are described. Test bench operation is considered in cases of the energy storage system working at various selected supercapacitor initial voltages. Maximal increase of possibility of vehicle test bench regenerative braking with minimal decrease of autonomous power supply mode possibility is investigated. There is estimated the energy storage system efficiency improving measures dependence from supercapacitor operational voltage ranges. Parameters at which the minimum losses of energy are observed are revealed. Dependence of energy storage system discharge power on the most admissible supercapacitor current is established.

Laboratory Test Bench for Research Network and Cloud Computing

At present moment, there is a great interest in development of information systems operating in cloud infrastructures. Generally, many of tasks remain unresolved such as tasks of optimization of large databases in a hybrid cloud infrastructure, quality of service (QoS) at different levels of cloud services, dynamic control of distribution of cloud resources in application systems and many others. Research and development of new solutions can be limited in case of using emulators or international commercial cloud services, due to the closed architecture and limited opportunities for experimentation. Article provides answers to questions on the establishment of a pilot cloud practically “at home” with the ability to adjust the width of the emulation channel and delays in data transmission. It also describes architecture and configuration of the experimental setup. The proposed modular structure can be expanded by available computing power.

Test Bench for Robotics and Autonomy： Overview and Test Results

In this paper, the TAS-I （Thales Alenia Space-Italy） Test Bench for Robotics and Autonomy （TBRA） is presented. It is based on a flexible and modular software architecture （Framework Engine）, in which each functional module （representing the GNC subsystems） implements a key functionality of the GNC （Guidance Navigation and Control）. Modules communicate by means of standardised interfaces designed for exchange of necessary information among the modules composing the entire system. This approach permits the interchange-ability of each subsystem without affecting the overall functionalities of the GNC system. In this paper, the TBRA system, together with the implemented functional modules will be described. Tests results will be reported and future development will be discussed.

钵苗移栽机取苗装置的设计与试验

设计了一种钵苗移栽机取苗装置,并对夹苗和松苗两种状态下的末端执行器进行运动仿真,从而选择合适行程的气缸或推杆作为原动件。选用凸轮机构用于顶苗,根据凸轮各阶段工作规律设计出合理的轮廓线,利用仿真验证出满足设计要求。试验结果表明:设计的取苗装置未取出率平均值为8.22%,取苗成功率平均值为91.78%,达到了设计目标。

俯仰式播种单体仿形性能检测试验台设计与试验

为解决播种单体仿形机构性能难以检测的问题,设计了俯仰式播种单体仿形性能检测试验台。阐述了试验台组成结构与工作原理,对其高速传动系统、液压升降系统、监控系统以及关键部件参数进行设计。应用ANSYS软件对台架整体和关键部件进行静力学分析和模态分析,验证结构设计的合理性。为检验俯仰式播种单体仿形性能检测试验台的实际检测效果,以德邦大为1205型牵引式免耕精量播种机播种单体为研究对象,先以液压杆伸出量与传送带速度为试验因素,以监控系统误差为评价指标进行试验。试验得出,在液压杆伸出量为0~200 mm范围内,监控系统角度传感器最大误差为0.69 mm;在传送带速度8~19 km/范围内,光电编码器最大误差为0.18 km/h。确认监控系统准确性后,再以单体速度为试验因素,采集速度8、10、12 km/h下地块的起伏数据为目标曲线,以地形起伏模拟曲线的绝对误差平均值为指标进行单因素试验,试验得出,所设计的试验台可有效模拟田间地面的起伏频率与起伏量,绝对误差平均值为1.86 mm,满足播种单体仿形性能检测需求。

电涡流缓速器优化设计与制动性能分析

文章在考虑去磁效应的基础上建立电涡流缓速器数学计算模型,采用涡流折算系数法求出闭合磁路磁感应强度,推导出电涡流缓速器电磁制动力矩表达式;在某汽车制动系统有限公司现有产品的基础上,将圆形极柱优化设计为扇形极柱,并利用Maxwell有限元仿真软件对不同长度扇形极柱的新型电涡流缓速器模型的制动力矩进行仿真分析;将最终确定的新型电涡流缓速器通过有限元仿真和台架实验与原产品进行对比验证。结果表明:新型电涡流缓速器与传统电涡流缓速器的制动扭矩在不同转速下变化的规律基本一致,制动性能有明显提升;仿真结果和实验结果最大误差小于5%,证明了新型电涡流缓速器的有效性和优化设计的正确性。

基于Optistruct的某皮卡汽车后桥壳轻量化优化研究

【目的】为研究某新款皮卡汽车后桥壳的静态特性及轻量化优化问题,【方法】采用有限元平台仿真与台架试验结合的研究方法。首先,在Hypermesh软件建立具有高计算精度的有限元模型;其次,使用ABAQUS仿真平台分析了桥壳在满载工况下的应力及位移,确定了危险截面位置;随后,通过Optistruct优化模块对桥壳和钢板板簧座等零部件进行了尺寸优化;最后,通过垂直弯曲静刚强度台架试验验证了轻量化优化的可靠性。【结果】有限元分析结果表明,桥壳的危险截面位于钢板板簧座与桥壳连接处,最大应力和变形量分别为307.20 MPa和1.440 mm。Optistruct尺寸优化后的桥壳重量由59.07 kg降低至52.55 kg,减重率11.04%。应力上升至310.10 MPa,但仍小于桥壳材料45钢的屈服强度355.00 MPa,变形量小于标准1.400 mm。台架试验结果表明,桥壳通过垂直弯曲静刚强度试验,符合汽车驱动桥台架试验标准。【结论】所建立的有限元模型具有较高的准确性,仿真结果与台架试验结果高度接近。经Optistruct优化后的桥壳具有良好的力学行为表现,该模块在桥壳轻量化优化方面具有较高的可靠性。

Torque effect on vibration behavior of high-speed train gearbox under internal and external excitations

The high-speed train transmission system,experiencing both the internal excitation originating from gear meshing and the external excitation originating from the wheel-rail interaction,exhibits complex dynamic behavior in the actual service environment.This paper focuses on the gearbox in the high-speed train to carry out the bench test,in which various operat-ing conditions(torques and rotation speeds)were set up and the excitation condition covering both internal and external was created.Acceleration responses on multiple positions of the gearbox were acquired in the test and the vibration behavior of the gearbox was studied.Meanwhile,a stochastic excitation modal test was also carried out on the test bench under different torques,and the modal parameter of the gearbox was identified.Finally,the sweep frequency response of the gearbox under gear meshing excitation was analyzed through dynamic modeling.The results showed that the torque has an attenuating effect on the amplitude of gear meshing frequency on the gearbox,and the effect of external excitation on the gearbox vibration cannot be ignored,especially under the rated operating condition.It was also found that the torque affects the modal param-eter of the gearbox significantly.The torque has a great effect on both the gear meshing stiffness and the bearing stiffness in the transmission system,which is the inherent reason for the changed modal characteristics observed in the modal test and affects the vibration behavior of the gearbox consequently.

试验环境的盘式制动器NVH特性研究

文中采用多体动力学和声学边界元等数值方法,研究某盘式制动器试验条件下的NVH(Noise,Vibration,Harshness)特性。首先,建立试验环境的制动器刚柔耦合模型,从结构、激励源和传递路径3个方面分析制动NVH特性影响因素;然后,运用声学边界元法仿真得到制动振动辐射的噪声,并与台架试验结果进行比较。结果表明:制动盘第2~5阶轴向模态,支架第2~3阶轴向模态,以及制动钳和连接板第1阶轴向模态等模态固有频率与台架试验噪声频率较接近,可能引起共振而产生制动噪声;在不影响制动性能的前提下,改变制动盘与摩擦衬片阻尼系数能改善制动NVH特性;悬架螺旋弹簧下端振动大,减振器与衬套对振动具有显著衰减作用;由仿真声压级云图发现,制动盘与摩擦片接触部位声压级最大,且随频率增加呈先增后减趋势,与台架试验对应测点的噪声结果进行直接比较,两者趋势一致。

无线射频压裂滑套系统模拟试验研究

将无线射频识别(RFID)技术应用到油水井压裂中,能够很好地解决现有压裂滑套存在的压裂级数受限、操作非智能等诸多问题。因井下工况复杂,理论分析与实际应用差别较大,为进一步系统地探究井下无线射频系统的开发应用,使用三维软件设计无线射频滑套模拟试验台,对标签的运动状态进行理论分析,并建立室内模拟试验平台,系统地进行井下相关试验。试验结果表明:标签选择有铁氧体磁芯,且天线绕制形式选用单层螺线管线圈,可以提高整个系统的性能;在系统电感值相同的情况下,单层螺线管天线轴向长度对阅读器模块能识别的标签最大通过速度有积极的影响;标签天线线圈与阅读器天线线圈平面之间的角度也会影响标签的识别率。研究结果对井下无线射频系统的开发应用具有一定的指导作用。

某点燃式大功率甲醇发动机样机台架试验研究

为开发13LM100甲醇新型发动机,使用新能源动力综合试验平台对甲醇发动机样机进行台架试验,对试验过程中先后出现的发动机起动困难、异常熄火以及扭矩不稳等故障现象进行排查分析并提出改进解决方案。结果表明:燃料温度为21.5℃、环境温度低于10℃且冷却液进液温度低于50℃时,发动机起动困难,通过发动机冷却液恒温系统将进液温度控制在50℃以上,可确保发动机顺利起动;冷却液回液温度高于91.5±1℃时,发动机异常熄火,通过发动机冷却液恒温系统将回液温度控制在90.5℃以下,可避免发动机异常熄火的情况;在排除燃油供给系统、点火系统、进气系统等因素后,发动机仍扭矩不稳,通过扫点调整废气再循环系统(EGR)流量系数并选取最佳试验结果对应的EGR率,可确保发动机运转平稳,扭矩稳定。

可调倾角编程式多功能取苗试验台设计与试验

针对现有取苗试验台不能满足多种型号钵盘和取苗机构进行取苗试验的需求,设计了一种由多个步进电机驱动、可调取苗机构倾角、可编程控制系统的多功能取苗试验台。该试验台通过调节取苗机构安装支架的位姿、改变钵盘驱动鼠笼钢丝间距以及所在圆周直径,可以适应不同型号钵盘和满足多种取苗机构的试验要求;通过编写控制器程序可控制3个步进电机联动并实现送苗装置的横、纵向送苗与取苗机构取苗进程相匹配。在三维软件中对试验台进行了建模、装配和虚拟仿真,在加工制造的物理样机上进行了2种型号钵盘和3种取苗机构的取苗试验。3次试验结果表明:在此试验台上能够顺利完成取苗试验,证明该试验台满足多种型号钵盘和多种类型取苗机构的试验需求。

面向个性化需求的燃料电池测试台价值评估方法

针对不同个性化需求的燃料电池测试台(fuel cell test bench,FCTB)难以评价和量化评估的问题,提出一种基于改进和声搜索算法的FCTB价值评估方法.针对不同FCTB的个性化需求,建立了FCTB综合评估指标体系;结合用户的个性化需求,采用模糊层次分析法分配指标权重,构建价值定量评估模型,将权重求取问题转换为约束优化问题;提出一种改进和声搜索算法对问题进行求解,通过设计解向量生成机制和参数自适应调整策略,用于提高传统和声搜索算法的求解效率和搜索能力.仿真结果表明,本文方法在计算效率和精度方面具有优势,并能够根据不同的需求特性实现对FCTB方案做出定量的价值评估.