A MODEL FOR THE RELIABILITY ANALYSIS OF STRUCTURE UNDER RANDOM STRESS RANGE LOADINGS（RDCDR MODEL）

ＡＭＯＤＥＬＦＯＲＴＨＥＲＥＬＩＡＢＩＬＩＴＹＡＮＡＬＹＳＩＳＯＦＳＴＲＵＣＴＵＲＥＵＮＤＥＲＲＡＮＤＯＭＳＴＲＥＳＳＲＡＮＧＥＬＯＡＤＩＮＧＳ（ＲＤＣＤＲＭＯＤＥＬ）ＡＭＯＤＥＬＦＯＲＴＨＥＲＥＬＩＡＢＩＬＩＴＹＡＮＡＬＹＳＩＳＯＦＳＴＲＵＣＴＵＲ...     

ITERATION SOLUTION OF THE MIXED FORMULATION IN NONLINEAR FEM

ＩＴＥＲＡＴＩＯＮ　ＳＯＬＵＴＩＯＮ　ＯＦ　ＴＨＥ　ＭＩＸＥＤ　ＦＯＲＭＵＬＡＴＩＯＮ　ＩＮ　ＮＯＮＬＩＮＥＡＲ　ＦＥＭＷａｎｇＳｈｏｕｍｅｉ（ＢｅｉｊｉｎｇＵｎｉｖｅｒｓｉｔｙｏｆＡｅｒｏｎａｕｔｉｃｓａｎｄＡｓｔｒｏｎａｕｔｉｃｓ，Ｂｅｉｊｉｎｇ...     

HYBRID POSITION/FORCE MANIPULATION OF MULTIFINGERED HAND

ＨＹＢＲＩＤＰＯＳＩＴＩＯＮ／ＦＯＲＣＥＭＡＮＩＰＵＬＡＴＩＯＮＯＦＭＵＬＴＩＦＩＮＧＥＲＥＤＨＡＮＤＧＵＡＮＹｉｓｈｅｎｇ（管贻生）,ＺＨＡＮＧＱｉｘｉａｎ（张启先）（ＲｏｂｏｔｉｃｓＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅ,ＢｅｉｊｉｎｇＵｎｉｖｅｒｓ...     

STOCHASTIC BOUNDARY ELEMENT METHODS FOR 3－D PROBLEMS WITH CENTRIFUGAL FORCES AND RELIABILITY ANALYSIS

ＳＴＯＣＨＡＳＴＩＣＢＯＵＮＤＡＲＹＥＬＥＭＥＮＴＭＥＴＨＯＤＳＦＯＲ３－ＤＰＲＯＢＬＥＭＳＷＩＴＨＣＥＮＴＲＩＦＵＧＡＬＦＯＲＣＥＳＡＮＤＲＥＬＩＡＢＩＬＩＴＹＡＮＡＬＹＳＩＳ￥ＷｅｎＷｅｉｄｏｎｇ；ＳｕｎＸｉａｏｌｉｎｇ（ＮａｎｊｉｎｇＵｎｉｖｅ...     

EXPERIMENTAL STUDY OF FRETTING WEAR OF TITANIUM ALLOY BEFORE AND AFTER LASER BEAM QUENCHING

ＥＸＰＥＲＩＭＥＮＴＡＬＳＴＵＤＹＯＦＦＲＥＴＴＩＮＧＷＥＡＲＯＦＴＩＴＡＮＩＵＭＡＬＬＯＹＢＥＦＯＲＥＡＮＤＡＦＴＥＲＬＡＳＥＲＢＥＡＭＱＵＥＮＣＨＩＮＧＤａｉＺｈｅｎｄｏｎｇ，ＴａｎｇＹａｘｉｎｇ，ＺｈａｎｇＨｏｎｇ，ＷａｎｇＭｉｎ（Ｄｅｐａｒｔ...     

PROBABILITY DAMAGE TOLERANCEEVALUATION METHOD FORMULTI-CRACKED STRUCTURE

ＰＲＯＢＡＢＩＬＩＴＹＤＡＭＡＧＥＴＯＬＥＲＡＮＣＥＥＶＡＬＵＡＴＩＯＮＭＥＴＨＯＤＦＯＲＭＵＬＴＩ－ＣＲＡＣＫＥＤＳＴＲＵＣＴＵＲＥＴｏｎｇＭｉｎｇｈｏ；ＦｅｉＢｉｎｊｕｎ；ＬｉｕＷｅｎｔｉｎｇ（ＢｅｉｊｉｎｇＵｎｉｖｅｒｓｉｔｙｏｆＡｅｒｏｎａｕ...     

高阶各向异性k－ε模型及在直通道湍流流场中的数值研究

ＡＨＩＧＨ－ＯＲＤＥＲＡＮＩＳＯＴＲＯＰＩＣＫ－εＭＯＤＥＬＡＮＤＩＴＳＮＵＭＥＲＩＣＡＬＩＮＶＥＳＴＩＧＡＴＩＯＮＩＮＴＷＯＤＩＭＥＮＳＩＯＮＡＬＴＵＲＢＵＬＥＮＴＦＬＯＷＦＩＥＬＤＳＬｉｕＺｈｅｎｇｘｉａｎ，ＳｏｎｇＢａｏｊｕｎ，ＧｕＣｈｕａｎｇ...     

EXPERIMENTAL AND NUMERICAL INVESTIGATIONS OF BOTH FLOW INDUCED CAVITY OSCILLATION AND ITS SUPPRESSION BY ACOUSTIC EXCITATION

ＥＸＰＥＲＩＭＥＮＴＡＬＡＮＤＮＵＭＥＲＩＣＡＬＩＮＶＥＳＴＩＧＡＴＩＯＮＳＯＦＢＯＴＨＦＬＯＷＩＮＤＵＣＥＤＣＡＶＩＴＹＯＳＣＩＬＬＡＴＩＯＮＡＮＤＩＴＳＳＵＰＰＲＥＳＳＩＯＮＢＹＡＣＯＵＳＴＩＣＥＸＣＩＴＡＴＩＯＮＬｕｏＢａｉｈｕａ；ＨｕＺｈａｎ...     

EXPERIMENTAL RESEARCH ON STRESS INTENSITY FACTOR K_Ⅲ FOR 3-D CRACK BY CAUSTICS

ＥＸＰＥＲＩＭＥＮＴＡＬＲＥＳＥＡＲＣＨＯＮＳＴＲＥＳＳＩＮＴＥＮＳＩＴＹＦＡＣＴＯＲＫⅢＦＯＲ３┐ＤＣＲＡＣＫＢＹＣＡＵＳＴＩＣＳＷｕＤａｆａｎｇ，ＧａｏＺｈｅｎｔｏｎｇ（ＩｎｓｔｉｔｕｔｅｏｆＳｏｌｉｄＭｅｃｈａｎｉｃｓ，ＢｅｉｊｉｎｇＵｎｉｖｅ...     

INFLUENCE OF DWELL TIME ON HIGH TEM-PERATURE LOW CYCLE FATIGUE (HTLCF) BEHAVIOR IN AN Nd-BEARING NEAR-α TITANIUM ALLOY

ＩＮＦＬＵＥＮＣＥＯＦＤＷＥＬＬＴＩＭＥＯＮＨＩＧＨＴＥＭＰＥＲＡＴＵＲＥＬＯＷＣＹＣＬＥＦＡＴＩＧＵＥ（ＨＴＬＣＦ）ＢＥＨＡＶＩＯＲＩＮＡＮＮｄＢＥＡＲＩＮＧＮＥＡＲαＴＩＴＡＮＩＵＭＡＬＬＯＹＺｈｕＺｈｉｓｈｏｕ，ＣａｏＣｈｕｎｘｉａｏ，Ｍ...     

后加载叶型叶栅的三维压力场及其对损失发展的影响

在低速环形叶栅风洞上对具有后部加载叶型的常规直叶片叶栅和弯曲叶片叶栅进行了吹风实验，得到了两种叶栅的叶片和上、下端壁表面的静压系数分布及气动性能。实验结果表明，后部加载叶型能够建立对应优良气动特性的叶栅内部三维压力场，同时采用弯叶片技术可进一步优化展向静压系数分布。     

可调桨距冲压空气涡轮气动特性实验与数值分析

冲压空气涡轮风洞实验主要目的是采用相似准则,模拟空中加油工作状态,测量涡轮输出功率,分析涡轮气动特性。实验分别使用励磁发电机和加油泵作为测功器,通过调桨变距并测量最大输出功率。气动特性实验表明在风洞气流速度比加油机最小飞行速度低16%的条件下,冲压涡轮输出功率即可满足加油需要。论文还采用高数值稳定性代数Baldwin-Lomax湍流模型模拟冲压涡轮全三维混合型流场,分析流场主要气动特性,讨论桨叶表面载荷的分布。数值模拟结果显示在冲压空气涡轮桨叶近轮毂区域需要进一步优化。      

高负荷缝隙弯曲扩压叶栅尾迹特性实验

实验研究了设计冲角下压气机采用带切向缝隙大转角弯曲叶片对叶栅出口尾迹特性的影响,结果表明,切向缝隙射流能够有效地改善高负荷扩压叶栅的尾迹低速、低总压特性,减少尾迹高熵流体的加入以及尾迹亏损,从而降低了栅后总损失。     

空气系统对核心机性能敏感性的影响

为了确定空气系统不同位置引气量对核心机性能的影响，给总体性能和空气系统设计提供依据，以某型核心机设计过 程为例，将空气系统设计迭代到总体性能设计中，研究了空气系统对核心机性能和部件特性的影响，并开展了空气系统对核心机 性能的敏感性分析。结果表明：每个引气位置引气量的增加均会导致燃烧室出口温度的升高，其中用于涡轮转子冷却的引气对燃 烧室出口温度的影响最大，其次为第5级压气机引气，再次为用于涡轮导向器冷却的引气，影响最小的为用于涡轮后机匣冷却的 引气。将空气系统设计结果迭代到核心机性能模型中，迭代后的压气机和涡轮工作特性发生了变化，压气机共同工作线受引气量 增加的影响稍微下移，涡轮落压比由于燃烧室出口温度的升高而减小。     

Modelling internal air systems ingas turbine engines

Rotating-disc systems can be used to model,experimentally and computationally,the flow and heat transfer that occur inside the internal cooling-air systems of gas turbine engines.These rotating-disc systems have been used successfully to simplify and understand some of the complex flows that occur in internal-air systems,and designers have used this insight to improve the cooling effectiveness,thereby increasing the engine efficiency and reducing the emissions.In this review paper,three important cases are considered:hot-gas ingress;the pre-swirl system;and buoyancy-induced flow.Ingress,or ingestion,occurs when hot gas from the mainstream gas path is ingested into the wheel-space between the turbine disc and its adjacent casing.Rim seals are fitted at the periphery of the system,and sealing flow is used to reduce or prevent ingress.However,too much sealing air reduces the engine efficiency,and too little can cause serious overheating,resulting in damage to the turbine rim and blade roots.Although the flow is three-dimensional and unsteady,there are encouraging signs that simple ‘orifice models’ could be used to estimate the amount of ingress into the wheel-space.In a pre-swirl system,the cooling air for the gas-turbine blades is swirled by stationary nozzles,and the air is delivered to the blades via receiver holes in the rotating turbine disc.Swirling the air reduces its temperature relative to the rotating blades,and the designer needs to calculate the air temperature and pressure drop in the system.The designer also needs to calculate the effect of this swirling flow on the heat transfer from the turbine disc to the air,as this has a significant effect on the temperature distribution and stresses in the disc.Recent experimental and computational studies have given a better understanding of the flow and heat transfer in these systems.Buoyancy-induced flow occurs in the cavity between two co-rotating compressor discs when the temperature of the discs is higher than that of the air in the cavity.Coriolis forces create cyclonic and anti-cyclonic circulation inside the cavity and,as such flows are three-dimensional and unsteady,the heat transfer from the discs to the air is difficult either to compute or to measure.The flow also tends to be unstable and one flow structure can change quasi-randomly to another,which makes it hard for designers of aero-engines to calculate the transient temperature changes and thermal stresses in the discs during take-off,cruise and landing conditions.Although recent CFD research has been successful in computing these flows,it will be many years before the designer can rely on computations unless they have been validated on reliable experimental data.      

气冷涡轮叶栅效率的计算方法

将气冷涡轮叶栅中的冷气与主流在边界层中的掺混模型和在边界层外的掺混层中的掺混模型结合起来, 建立了一个预估气冷涡轮叶栅效率的计算模型。根据该模型利用回转面叶栅无粘流场的计算结果和二维叶面边界层流动的计算结果来预估气冷涡轮叶栅的效率。该算法为气冷涡轮叶栅的优化气动设计提供了一个计算手段。      

考虑冷气的多级涡轮翘曲S1流面的气动优化

为了缩短涡轮气动设计的周期,进一步发掘涡轮叶型的改进潜力,搭建了多级涡轮的翘曲S1流面气动优化平台.该平台具有速度快,周期短的特点.在考虑冷气的前提下,对多级叶片进行多层并行优化,避免了单列优化后叶列间匹配差的缺点,同时克服了多层S1流面的气动效率此消彼长的缺陷.对某型两级高压涡轮进行了气动优化设计,优化后10%,50%,90%叶高的S1流面的考虑冷气的气动效率分别提高了0.569%,0.490%,0.405%;第1级和第2级考虑冷气的气动效率分别提高了0.18%,0.05%;涡轮整体气动效率提高了0.15%;优化效果明显.经过分析可知,优化有效减小第1级导叶的通道横向二次流损失和第1级动叶的激波损失,第2级的原始叶型设计较为合理.下端壁喷射冷气是降低S1流面优化有效性的重要原因.     

TA-6发动机的引气特性

在TA-6发动机的压气机出口处引气,得到了发动机转速不变条件件下压气机增压比、引气阀压力损失系数、引气管内气流总压和引气气流温度与引气量之间的关系。研究表明,相对引气量在9～22％范围内变化时,TA-6发动机流量几乎不变,压气机增压比变化仅5％,引气压力为1.27×10~2～2.45×10~5Pa,引气温度约473K。所得结果可为燃气涡轮装置引气设计提供参考。     

定向结晶气冷涡轮叶片应力分析

本文利用大型非线性有限元通用程序对定向凝固结晶的气冷叶片进行了热弹性分析。对DZ-22材料性能常数进行了分析和确定。建立了横观各向同性的本构模型。根据叶片模型和最大工作状态选用八节点三维元计算了离心应力、热应力和总的当量应力, 作了相应的前后置处理。      

跨、超声速吸附式压气机平面叶栅试验

对跨、超声速吸附式压气机平面叶栅进行了试验研究,试验针对若干抽气位置、抽气量和流动条件不同的叶栅工作状态进行,结果表明:一般在通道激波后、附面层分离前抽气对控制叶片附面层在逆压力梯度区的发展、抑制分离、降低叶栅损失、升叶栅气动性能有较明显的效果;在跨声速叶栅中,抽气量大于某个时抽气才能起到减小损失、改善性能的作用.