Structural and Conceptual Design Analysis of an Axial Compressor for a 100 MW Industrial Gas Turbine (IND100)

The structural design of the IND100 axial compressor requires a multistage interrelationship between the thermodynamic, aerodynamic, mechanical design and structural integrity analysis of the component. These design criteria, sometimes act in opposition, hence engineering balance is employed within the specified design performance limits. This paper presents the structural and conceptual design of a sixteen stage single shaft high pressure compressor of IND100 with an overall pressure ratio of 12 and mass flow of 310 kg/s at ISOSLS conditions. Furthermore, in order to evaluate the conceptual design analysis, basic parameters like compressor sizing, load and blade mass, disc stress analysis, bearings and material selections, conceptual disc design and rotor dynamics are considered using existing tools and analytical technique. These techniques employed the basic thermodynamic and aerodynamic theory of axial flow compressors to determine the temperature and pressure for all stages, geometrical parameters, velocity triangle, and weight and stress calculations of the compressor disc using Sagerser Empirical Weight Estimation. The result analysis shows a constant hub diameter annulus configuration with compressor overall axial length of 3.75 m, tip blade speed of 301 m/s, maximum blade centrifugal force stress of 170 MPa, with major emphasis on industrial application for the structural component design selections.

Design of axial flaps with color Doppler flow imaging technique for repairing deep wounds of heels

To report the methods and effect of axial pattern flap on lower limb in repairing deep wounds of heels by using color Doppler flow imaging (CDFI) technique so as to solve the ever before problems that the vessel can not be displayed in designing axial flap.Methods Suitable axial flaps on lower limbs were selected according to the character of the wounds.There were 25 flaps including 10 cases of the distal-based sural neurovascular flap,nine medial sole flap and six medial leg flap.All the axial pattern flaps were designed on the basis of traditional design ways before operation;then,CDFI appliance with high resolution was used to examine the starting spot,exterior diameter,trail and length of the flap’s major artery.The flaps were redesigned according to the results of CDFI and transferred to cover the wounds.In the meantime,both the results of operation and examination were compared.Results The major artery’s starting spot,exterior diameter,trail and anatomic layers were displayed clearly,in consistency with the results of operation.The flaps survived completely and recovered well,with perfect appearance,color and arthral function.Conclusion CDFI is a simple,macroscopic and atraumatic method for designing the axial pattern flap on lower limb,can provide more scientific and accurate evidence for preoperative determination of flap transplantation and is worthy of clinical application.10 refs,4 figs,2 tabs.

Design of Axial-Flux Motor for Traction Application

This paper deals with the design of high power – low dimensions axial-flux permanent-magnet motor intended for trac-tion application. First, two motor configurations are analytically designed and compared using finite element calcula-tion. Then, the configuration yielding the best performances is integrated and modelled with the whole traction chain under MATLAB/SIMULINK environment in order to demonstrate the motor operation on a large speed band.

基于Geomagic Design X的轴流式风机叶片逆向建模

以轴流式风机叶片为例,详细阐述了逆向建模的思路和流程,并利用逆向工程软件Geomagic Design X对点云数据进行处理,得到了高质量的三维模型,并通过Live Transfer技术将模型导入到Solidworks软件中。该方法既可获得高质量的三维模型,还可缩短产品开发周期,具有较好的应用价值。

Oil–water pre-separation with a novel axial hydrocyclone

A novel hydrocyclone with guide vanes, named as axial hydrocyclone(AHC), is designed to tackle the problem of oil–water separation faced by most mature oilfields. Optimal design of the AHC is carried out by using numerical methods. The effects of guide vanes, cone angle, tapered angle and overflow pipe on the oil–water separation are discussed in this paper. The results show that a double swirling flow is generated in the tapered section where oil–water separation occurs. Both the cylindrical and the tapered section have important influences on AHC performance. On the basis of single factor results, response surface methodology is employed to optimize the AHC design. The experimental results indicate that the novel AHC has an excellent performance for the oil–water separation.

Design Research on Drive System of Underwater Tapping Machine

The underwater tapping machine is composed of a center bit, a tapping cutter, a seal box, a main drive box, a boring bar assembly, a envelop, a gear case, a counter and so on. The drive system in underwater tapping machine consists of a worm drive, a gear drive system and a screw drive. The worm drive is in the main drive box. The worm is connected with a hydraulic motor and driven by the hydraulic motor. The gear drive system is a combined gear train which is the combinations of the fixed axes and differential gear train in the gear case. On the one hand, by means of the fixed axes gear trains the turn and power of transmission shaft are transferred to the boring bar and the screw rod, causing differential turn between the boring bar and the screw rod. On the other hand, the turns of the boring bar and the screw rod are transferred to the differential gear train. The differential gear train is used to drive a special counter to count axial travel of the boring bar. The screw drive is composed of a feed screw and a nut on the boring bar. There is the differential turn between the boring bar and the feed screw. By means of the nut, the boring bar can feed automatically. With the movement of the sliding gear 7 in the gear case, the designed drive system can also be provided with the ability of fast forward and fast backward movement of the boring bar in its idle motion, resulting in the increase of the tapping efficiency.

基于有限相似方法的轴压加筋板极限强度相似缩比准则研究

在对船体结构进行相似缩比试验设计时,通常采用方向性量纲分析法。然而,传统的基于弹性理论的量纲分析法不能反映结构材料非线性过程,因而限制了其在船体结构缩比模型极限强度试验中的应用。本文基于有限相似方法,通过匹配物理空间与试验空间中的输运方程,获得结构几何尺寸、材料密度和时间的比例因子,推导得到加筋板结构缩比模型与原模型的非线性过程相似关系,分析材料参数对非线性相似过程的影响。通过开展不同缩比比例、不同材料参数的加筋板轴压极限强度数值计算,验证基于有限相似方法缩比准则的有效性。分析表明,基于有限相似方法的轴压加筋板极限强度缩比准则可以很好地体现材料的非线性特性,可以通过缩比模型结果对原模型的极限强度取得良好的预报效果。

装配式带夹芯保温槽型玻璃钢-钢板-槽钢-混凝土组合剪力墙轴压性能研究

提出一种装配式带夹芯保温槽型玻璃钢-钢板-槽钢-混凝土组合剪力墙,设计3个具有不同配筋形式和混凝土种类的墙板试件进行轴心受压试验,获得墙板在轴压作用下的破坏模式、荷载-位移曲线、荷载-应变曲线、承载力储备系数、延性系数、材料利用率等性能指标。通过ABAQUS有限元分析软件对墙板进行参数化分析,研究内嵌钢板强度和厚度对其轴压性能的影响。结果表明,墙板具有良好的承载力储备能力和延性性能;混凝土中掺入1%体积比的钢纤维可显著提高墙板内混凝土的抗拉性能,使混凝土强度得到更加充分的利用,布置钢筋可以显著提高墙板延性;墙板的承载力和延性随内嵌钢板厚度和强度的增加而增大,强度为Q355、厚度为4、6mm时,墙板材料利用率更高。提出适用于该类墙板的轴压承载力设计公式,考虑钢板屈曲和截面组合效应的墙板轴心受压承载力设计公式计算结果较精确。

基于Kriging插值代理模型的轴流式止回阀多目标优化

基于Kriging插值代理模型,对轴流式止回阀的各项性能进行综合优化,具体的优化目标为:降低正向流阻;减小阀芯振动;提升止回性能。通过试验设计方案找到影响轴流式止回阀正向流阻的主要结构参数因素,并以其作为优化对象,通过Kriging插值法拟合主要结构参数对应的性能样本点,在保证拟合精度的情况下,使用NSGA-II遗传算法同时对3个主要结构参数进行多目标优化,得到了三目标Pareto前沿,经过权衡不同因素对性能指标的影响大小,最终得到了综合性能最优的结构参数为:阀瓣丰满度系数α_(1)=2.199,阀芯长度L=386.322 mm,阀芯半径R=113.997 mm。其对应的止回阀性能为:正向出口流量Q=161.839 kg/s,正向出口流速v=3.30235 m/s,止回阀进口压力p=97632.2287 Pa。相比优化之前,阀门正向流阻减小了1.2%,阀芯振动降低了0.24%,止回性能提升了2.3%。

细长焊接圆钢管轴心受压稳定承载力研究

为研究细长焊接圆钢管轴压稳定性能,对30根试件进了轴压试验,分析了试件失稳变形的特征,比较了试件的稳定系数与我国规范中稳定曲线的关系,并考虑钢管几何初始缺陷和残余应力对其稳定承载力进行了有限元分析。研究表明:细长焊接圆钢管的几何初始缺陷具有较大离散性,与我国规范规定值不同,正则化长细比在1.0~1.3区间时,试验得到的稳定系数低于规范值,最大相差-24.4%;几何初始缺陷小于1/500杆长时,可采用规范值进行设计;而几何初始缺陷大于1/500杆长时,建议重新制定压杆曲线。最后,给出了细长焊接圆钢管在8种初始缺陷下的压杆稳定曲线。

异径铝合金薄壁圆管的加热塑性连接方法与模具设计

铝合金薄壁管在轴向压缩连接时开裂导致连接失效。为提高铝合金的压缩塑性成形性,进行了可加热的不等径管塑性连接模具设计。利用有限元软件对加热塑性连接过程中模具的热应力和热传递进行了数值模拟,用正交试验法对模具散热系统结构参数进行了分析,并进行了模具制作和不等直径铝合金管的连接接头试制。结果表明,20℃和600℃下模具的最大应力均低于模具材料对应温度下的屈服强度,满足钢、铝金属材料的加热塑性连接工艺需求。设计的散热系统可有效减缓模具热量向拉伸机的传递。300℃下该模具成功将Φ44和Φ30的两铝合金管进行了连接。说明了模具设计的合理性和连接工艺的可行性。为后续的工程应用提供指导。

眼轴测量对先天性斜视手术量的校正

目的参照眼轴测量结果设计先天性内/外斜视手术量,比较先天性斜视常规手术量与校正手术量的矫正效果差异。方法回顾性临床研究。2017年2月至2022年6月在南京医科大学附属儿童医院行斜视矫正手术的254例先天性内/外斜视患儿。依据手术设计方式划分为A组127例,B组127例,A组单纯以斜视度按常规设计手术量,B组根据眼轴长度对以斜视度设计的手术量进行校正。对A、B组术后1周、3个月、6个月手术效果进行比较。结果(1)组间正位率比较,术后1周,A、B组正位率分别为84.3%、85.8%,差异无统计学意义(P>0.05),术后3个月,B组正位率78.0%,比A组66.9%高,差异有统计学意义(P<0.05),术后6个月,B组正位率76.9%,比A组63.5%高,差异有统计学意义(P<0.05)。(2)当眼轴<22 mm时,A、B两组术后1周的正位率分别为84.0%、85.2%,术后3个月的正位率分别为64.9%、78.4%,术后6个月的正位率分别为63.8%、77.3%。当眼轴≥22 mm且<26 mm时,A、B两组术后1周的正位率分别为84.8%、87.2%,术后3个月的正位率分别为72.7%、76.9%,术后6个月的正位率分别为60.6%、69.2%。当眼轴<22 mm时,两组术后1周正位率差异无统计学意义(P>0.05),术后3个月、术后6个月均有统计学差异(均P<0.05),当眼轴≥22 mm且<26 mm时,两组术后1周、3个月、6个月正位率差异无统计学意义(均P>0.05)。(3)组间手术满意度比较,B组满意度83.5%比A组69.3%高,差异有统计学意义(P<0.05)。结论在排除其它影响因素下,根据眼轴长度对传统手术量进行校正有利于提高先天性斜视的术后效果和手术满意度。该方法可为斜视手术量设计提供参考。

内压作用下U形波纹管轴向补偿能力研究

为研究内压作用下波纹管的轴向补偿能力,论文将U形波纹管简化为梁模型推导了内压作用下波纹管轴向补偿能力计算公式,并基于有限元建模方法计算了U形波纹管的轴向补偿能力数值,得到了内压作用下U形波纹管轴向补偿能力数值会随压力增大而呈线性增大的结论,分析了各结构参数变化对带压状态下U形波纹管轴向的补偿能力数值的影响程度,对U形波纹管带压设计提供了参考。

基于燃油离心泵叶轮轴向力测试技术的研究

燃油离心泵的叶轮轴向力平衡设计是提升产品性能、寿命、可靠性等技术指标的重要途径,随着航空发动机技术的发展,对燃油离心泵叶轮轴向力平衡设计提出了更为苛刻的要求;现有设计技术、仿真技术、测试技术难以准确指导叶轮轴向力平衡设计,造成燃油离心泵异常磨损等故障频发。通过对燃油离心泵结构特征、工作原理进行分析,设计了一种燃油离心泵工作过程中测试叶轮轴向力的新技术,该技术将燃油离心泵工作过程中承载的轴向力传递给作动筒活塞,再使用闭环控制原理,控制作动筒两腔液压力保证在叶轮轴向力作用下作动筒活塞位置保持不变,通过作动筒两腔液压力和液压作用面积即可算出叶轮轴向力的大小;本研究的测试技术可以有效指导燃油离心泵叶轮轴向力平衡设计,优化产品结构从而提高产品可靠性。

新型Halbach阵列盘式永磁电机的磁场解析

基于印制电路板(PCB)技术的盘式永磁电机(AFPMM)提出一种新型Halbach阵列的转子结构,该阵列结构简单、易于优化。运用矢量磁位法对新型转子产生的空载气隙磁密进行解析推导,获得关于气隙磁场的数学模型。基于该模型,保持永磁体总用量不变,以永磁体极弧系数比和径向长度比作为优化变量,气隙磁密基波幅值和谐波畸变率作为优化目标,确立最优转子结构参数。三维有限元仿真结果表明,解析法所得的气隙磁密波形与有限元法基本一致,验证了所提出解析模型的合理性。与传统Halbach阵列相比,新型Halbach阵列气隙磁密基波幅值提升了10.3%,同时谐波畸变率由19.8%降至4.8%,优化效果明显,可以有效降低高频工况下电机的涡流损耗、提升电机效率。最后制造一台样机进行相关实验测试,验证了解析和仿真分析的正确性,对PCB定子AFPMM的设计具有一定参考价值。

轴扭耦合冲击器结构设计与室内试验

为提高PDC钻头切削齿在硬地层中的吃入深度、消除扭转振动带来的危害,在自激换向式扭冲总成结构的基础上,增设水力脉冲式轴冲总成,利用扭冲总成拨叉带动轴冲总成动盘阀同步旋转,使过流面积发生周期性变化,产生水力脉冲轴冲载荷,与扭冲载荷一起形成轴扭耦合冲击,设计出一种结构简单、冲击频率相同的新型轴扭耦合冲击器。同时,基于能量转换与守恒定律,建立了冲击器性能参数数学模型,并开展了轴扭耦合冲击器性能参数室内试验。试验结果表明,该轴扭耦合冲击器的压降、轴冲载荷与流量平方呈正比,扭冲载荷、冲击频率与流量呈线性增大关系,最大相对误差仅7.91%,验证了该数学模型的准确性。研究结果可为同类冲击钻井工具的开发提供理论指导。

跟踪成像复合轴光学系统设计

空间望远镜的部件振动与相对运动会导致像移,为抑制振动引起的像移,可在光路中加入快速反射镜对像移进行抑制(二级稳像),然而快反镜较小的通光口径与稳像时造成的像旋限制了应用范围。为此,围绕以快反镜实现二级稳像的同轴共光路跟踪成像复合轴光学系统,分析对比反射式与折反式两种同轴无焦系统各自的特点,选择可实现较大扩束比的折反式无焦系统作为复合轴光学系统的前组,以满足光路中快反镜小通光口径的要求。根据像移补偿与像旋产生的机理构建数学模型,使用MATLAB分析仿真快反镜补偿线性像移时,探测器不同位置上像旋对调制传递函数的影响,并根据后组焦距与边缘视场调制传递函数的关系图,选择合适的后组焦距将像旋对调制传递函数的影响降低在合理范围。设计出焦距为9200 mm、快反镜通光口径小于30 mm的复合轴光学系统,并将像旋造成的调制传递函数下降控制在10%内。

竖向轴心荷载作用下的公路桥梁桩基设计与施工技术研究

以钻孔灌注桩为研究对象,结合工程实例,对承受垂直方向负荷的公路桥梁桩基的设计进行分析,通过桩型和持力层的选择、单桩竖向承载力特征值的验算、桩基数量和桩长选择来确定设计方案,并对公路桥梁桩基钻孔灌注桩施工工艺进程详细介绍。

基于有限元仿真和试验验证的锥形扩展台面结构优化设计

振动台台面性能优劣直接关系到试验结果。本研究旨在对SAI60-H560B-16/LP型电动振动台的扩展台面进行设计,解决原台面一阶共振频率较低和有效使用面积较小的问题。拟定了两种扩展台面尺寸,分别为700 mm×700 mm和1000 mm×1000 mm,通过ANSYS建模并计算扩展台面前20阶共振频率以及在正弦振动载荷作用下扩展台面的等效米赛斯应力;对扩展台面的一阶谐振频率和加速度均匀性进行了实物测试。结果显示,两种尺寸的扩展台面一阶轴向共振频率较原台面提高,等效米赛斯应力均小于疲劳强度;所测5个控制点加速度均方根满足目标值。研究成果为其他振动台扩展台面的优化设计提供了参考。

超低转速轴流压缩机气动设计

压缩机转速越低转子叶片离心力越小、结构强度要求越低、噪声越低。利用一种负出气角超弯扩压叶型,进行压缩机转子叶片设计,达到给定压比、流量,实现压缩机超高负荷、超低转速。选定设计载荷系数为1.147,大幅度高于常规载荷系数0.4;在二维叶型和三维叶片设计过程中采用自动优化设计方法。计算机数值模拟结果表明:所设计的压缩机级可达到给定的设计点流量和压比,具有较高的级效率;由于转子叶片通道后段收敛不易产生流动分离,具有很大的喘振裕度。