In this paper, we present a transient-format time-continuous Galerkin finite element method for fully intrinsic geometrically exact beam equations that are energy-consistent. Within the grid of space and time, we derive governing equations for elements using the Galerkin method and the time finite element method, implement variable interpolation via Legendre functions, and establish an assembly process for space–time finite element equations. The key achievement is the realization of the free order variation of the program, which provides a basis for future research on adaptive algorithms. In particular, the variable order method reduces the quality requirements for the mesh. In regions with a higher degree of nonlinearity, it is easier to increase the variable order, and the result is smoother. Meanwhile, increasing the interpolation order effectively enhances computational accuracy. Introducing kinematical equations of rotation with Lagrange operators completely imposes the conservative loads on fully intrinsic equations. This means that loads in the inertial coordinate system, such as gravity, can also be iterated synchronously in the deformed coordinate system. Through a set of illustrative examples, our algorithm demonstrates effectiveness in addressing conservative loads, elastic coupling deformation, and dynamic response, demonstrating the ability to analyze elastically coupled dynamic problems pertaining to helicopter rotors.

In this paper, a space-time finite element method based on a Galerkin-weighted residual method is proposed to solve the nonlinear fully intrinsic equations of geometrically exact beam which are first-order partial differential equations about time and space. Therefore, it is natural to discretize it in time and space simultaneously. Considering the continuity and intrinsic boundary conditions in the spatial direction and the continuity and periodic boundary conditions in the time direction, the boundary value scheme of space-time finite element for solving the full intrinsic equations is derived. This method has been successfully applied to the static analysis and dynamic response solution of the fully intrinsic equations of nonlinear geometrically exact beam. The numerical results of several examples are compared with the analytical solution, existing algorithms, and literature to illustrate the applicability, accuracy and efficiency of this method.

为了解决校园疫情防控过程中传统手段面临的通传不畅、手工表格、组织低效等现实问题,从而充分发挥信息技术实时性、准确性优势,通过建设大数据分析系统,将各类疫情防控系统和流程数据清洗、分析和呈现,全面掌握校园疫情防控各个环节当前状态和发展趋势,为做好疫情防控工作、保护师生健康安全提供科学决策支持.

不稳定燃烧存在多种模式,不同模式会导致后继燃烧状态的不同演化,对燃烧室燃烧模式的实时预测能够为抑制不稳定燃烧提供依据并提高燃烧室设计效率.首先对模型旋流燃烧室不同工况下不稳定燃烧特性进行实验研究,获得动态压力脉动数据;随后建立不稳定燃烧模式-压力脉动数据库;最后在该数据库的基础上,采用隐马尔可夫模型(HMM)作为学习和预测工具,建立模式与压力脉动信号之间的概率模型并对不稳定燃烧模式进行在线识别与预测.研究结果表明,基于实验数据的HMM方法能够在毫秒级准确预测不稳定燃烧是否发生,并且能够较准确识别不稳定燃烧模式.

为进一步深化数据治理、流程再造,解决师生跨部门多业务办事问题,南京航空航天大学(以下简称"南航")立足学校现有信息化建设基础,以用户为核心,依据场景聚合业务,形成专题服务,建设具有南航特色的"一网通办".

In this paper, a differential quadrature method of high-order precision (DQ−Pade), which is equivalent to the generalized Pade approximation for approximating the end of a time or spatial interval, is used to solve nonlinear fully intrinsic equations of beams. The equations are a set of first-order differential equations with respect to time and space, and the explicit unknowns of the equations involve only forces, moments, velocity and angular velocity, without displacements and rotations. Based on the DQ−Pade method, the spatial and temporal discrete forms of fully intrinsic equations were derived. To verify the effectiveness and applicability of the proposed method for discretizing the fully intrinsic equations, different examples available in the literatures were considered. It was found that when using the DQ−Pade method, the solutions of the intrinsic beam equations are obviously superior to those found by some other usual algorithms in efficiency and computational accuracy.

针对能源动力专业研究生需要掌握"流体力学""热力学""燃烧学"等课程知识的现实需求,设计了综合性专业基础课——"化学反应流的理论与计算",参考国内外多本经典教材,编写了讲义.授课中采用了讲授式、启发式、翻转课堂和专题实践教学4种教学方式.课程设计与教学手段为相似专业研究生课程的设置提供参考,对于领域跨度大、知识难度高、独立思考性强的面向研究生专业课程的设计及教学有借鉴意义.

云计算技术具有虚拟化、高可靠、高可扩展性、极简运维等突出优势,将云计算技术应用于高校数据中心建设可以有效缓解高校数据中心痛点问题.在简要分析了高校数据中心建设现状后,介绍了云计算的基本概念、技术特点、部署模式和服务类型,重点阐述了基于云计算的高校数据中心设计.对高校云数据中心的主要需求进行了分析,给出了系统设计的总体框架,分别从IT资源、云平台、高可用等维度,对计算资源、存储资源、网络资源及其虚拟化进行了设计,提出了跨校区主备数据中心系统实现方案,并简要分析了潜在的问题和弊端.

“双一流”建设对高校教学管理提出了更高的要求.针对多媒体教室等信息化设施设备在使用与管理过程中遇到的问题,在分析多媒体教室管理和使用现状的基础上,通过技术更新,长效管理制度,多部门协同,提出一套行之有效又符合“双一流”高校建设的多媒体教室管理方法和措施,为“双一流”建设背景下高校教学管理、尤其是多媒体管理提供参考.

首先讨论轮毂电机控制目标,依据横摆角速度与质心侧偏角对车身进行稳定性分析,然后结合车辆转向工况讨论了以稳定性为目标的转矩协调控制方法.最后在CarSim软件中创建车辆动力学模型,在Matlab/Simulink中创建转矩协调控制模型,通过CarSim和Matlab/Simulink联合仿真,验证文章中的转矩协调控制策略可以提高车辆稳定性.

The strong aerodynamic interference exists between the upper and lower rotors of a coaxial high speed helicopter,w hich has a significantly influence on the aerodynamic characteristics of the ro-tors.Based on the feature and considering the efficiency of the aeroelastic coupling calculation,the ini-tial induced velocity distribution calculated by rigid-wake model,together with the wake geometry fea-ture of a single rotor calculated by free-wake model,are the initial iteration values for the prescribed-wake model of a coaxial helicopter.The main calculation modules:The blade fully intrinsic dynamic e-quations of the coaxial twin rotors,the constraint equations between the blade and the bearings and the aerodynamic models,including the wake models and Leishman-Beddoes unsteady dynamic stall model and Pitt-Peters dynamic inflow model,are the basis for establishing a computational model of the coaxial twin rotors vibration load considering the aerodynamic interference and coupling iteration between the upper and lower rotor.The forces and moments on the sample XH-59A,which is the certification ma-chine of Sikorsky,are calculated with the help of the model.The computational results are in good coin-cidence with those from the wind tunnel test.

考虑到涡轮转子径向变形对涡轮叶尖径向间隙以及篦齿径向封严间隙的影响,提出涡轮转子径向变形多目标协同稳健性优化方法.利用基于Kriging模型的分布式协同响应面法(DCRSM)分别建立涡轮转子和涡轮篦齿的参数与径向变形间的响应面模型,并求解单目标下的稳健最优解.采用理想点法建立涡轮转子和篦齿径向变形多目标协同稳健性优化模型,并进行多目标协同稳健性优化求解.优化结果显示:提出的多目标协同稳健性优化方法与单目标稳健性优化方法相比涡轮转子和篦齿径向变形量的标准差分别降低了2.6％和4.9％.提出的方法为涡轮转子参数设定提供一定的参考.

在对复杂不规则的几何体应用商业软件划分结构化网格时,需要手动对其切割分区.手动分区耗时长,分区质量也不高.针对以上问题,提出一套分区质量的评价体系,在基于分区质量指标基础上利用遗传算法自动求解出几何体的优化分区.以涡轮叶片叶盆侧分区为例提出两种优化方法:一种是串行优化:按照一定的顺序串行产生优化分区;另一种是整体优化:同时对所有分区采取整体优化策略.研究结果证明这两种方法都可以快速地自动确定涡轮叶片的最优结构化网格分区,提高效率,保证高质量网格的生成.

In order to reduce the influence of parameter uncertainty on the radial deformation of straight-through labyrinth seal of aeroengine, a robust optimization method was proposed based on Least Squares Support Vector Machine (LS-SVM)and probabilistic quantile interval model. The LS-SVM was used to establish the response surface approximation model between parameters and labyrinth seal radial deformation. Considering the diversity of uncertainty distribution types of parameters, the probabilistic quantile interval method was adopted to establish robust optimization model. The method was used to optimize the radial deformation of labyrinth seal. The results show that the probabilistic quantile interval of radial deformation on labyrinth seal is reduced by 6％compared with that before optimization. The effectiveness of the method is also verified by the results of parameter sensitivity analysis.

为了解决Taguchi法在计算一次装配成功率时存在峰度值误差大、计算精度低、计算量大等问题,采用一种改进Taguchi法计算航空发动机压气机的装配成功率.将组成环尺寸作为改进Taguchi法封闭环的影响要素,利用分步正交的概念将组成环分组并求解部分装配响应函数,根据Pearson理论判断其分布类型,将部分装配响应函数作为组成环再次正交试验求得总体装配响应函数的分布类型,得到响应分布图并计算其装配率.利用极差法分析组成环各水平因素对于装配响应函数的影响.在改进Taguchi法的理论基础上,以航空发动机压气机级轴向间隙为实例,采用改进Taguchi法计算其装配成功率,应用蒙特卡洛法及Taguchi法进行对比分析,对比发现改进Taguchi法峰度误差由Taguchi法的12.46％降低到1.39％,验证了改进Taguchi法的有效性.

In order to predict the performance of gas turbine generator units,based on a large number of gas turbine generator unit's operation data and the method of multiple linear regression analysis,the predicted mathematical models of gas turbine power and gas turbine efficiency through the initial import conditions were obtained.The part of PG9171E type gas turbine generator unit's historical operating data was used as training samples,then the multiple linear regression mathematical model of gas turbine performance was established,validated and analyzed.The results showed:based on multiple linear regression analysis,the performance of gas turbine generator unit can be predicted effectively through the initial import conditions;judging from the analysis of predicted results,multiple linear regression analysis for gas turbine power prediction is superior to the prediction of gas turbine efficiency.This method can provide some reference value for the big data analysis and economical operation of the power plant.

In order to achieve higher levels of efficiency of structured mesh generation,an approach towards automatic blocking applied into turbine blade is presented,based on the parameters of parameterized model,the envelope planes can be calculated respectively,the hexahedral topology is constructed by generating the auxiliary planes in the computational domain,which can be used for the structured mesh generation.This paper presents a concept for computational grid optimization performed by decomposing complex domain into simpler parts by filling virtual structures.The results show that this strategy contributes to less manual intervention and shorter mesh generation period,and it can be used for turbine blades that have the same structures,which is very helpful for the automatic optimization of blade design.

The degree of controllability of multi-rotors was solved to evaluate the control levels of the aircraft system,based on the approximation calculation method of controllability proposed by George Klein et al.Firstly,variations of the degree of controllability were analyzed under three conditions of one steering gear broken down,one motor breakoff and the normal flight respectively on the variable-pitch quadrotor.And then with the comparative analysis of variable-pitch and fixed-pitch of four,six and eight rotors,the results showed that the degree of controllability of the system was positively correlated with the number of the rotors.Finally,the conception of degree of controllability was applied to two kinds of hybrid-electric hexacopter compared with the conventional electric hexacopter with fixed-pitch.And the research results indicated that the proper configuration could improve the degree of controllability remarkably.

为了掌握低排放燃烧室的污染物排放情况,对其化学反应网络器(CRN)模型的参数化进行研究.对爬升工况下燃烧室CFD数值模拟结果进行分析,划分燃烧室的结构,得到燃烧室的CRN模型.再利用自编程软件对燃烧室的结构参数和进口参数进行参数化定义,并把参数化的CRN模型在不同工况下的模拟结果与试验结果分别比较.结果表明:在慢车工况下二者相差不大,在爬升工况下二者差异也在允许误差范围之内.验证了该模型可行性较好,该参数化CRN模型可用于预测低排放燃烧室的污染物排放量和出口温度.

定量评估土地利用绩效并诊断其障碍因子,是提高区域土地利用绩效水平的有效途径.该文综合考虑土地利用经济绩效、社会绩效、生态绩效和管理绩效4个子系统,建立区域土地利用绩效评价指标体系,结合熵权TOPSIS模型和障碍度模型,对安徽省近15 a(2000-2014年)的土地利用情况进行绩效评价和障碍因子诊断,并基于评价结果,运用GM(1,1)模型对安徽省未来5 a(2015-2019年)土地利用子系统绩效变化态势进行预测和分析.结果表明:安徽省土地利用综合绩效经历了较差—中级—良好—优质的发展过程,结合土地利用绩效的年均增长速度,可以分为绩效较差但高速增长(2000-2004年)、绩效中级但较快增长(2005-2009年)、绩效良好但低速增长(2010-2011年)和绩效优质且快速增长(2008-2014年)4个发展阶段.4个子系统绩效水平基本逐年提升,但变化趋势存在差异,经济绩效和管理绩效呈线性增长态势,社会绩效和生态绩效呈波动起伏变化的上升趋势;未来5a,经济绩效子系统年均增长速度最快,社会绩效和管理绩效子系统次之,生态绩效子系统增速最慢.经济绩效子系统障碍度最大,其后依次是社会、生态和管理绩效子系统;2000-2008年,建成区工业增加值等3个指标一直稳居前3位,人民生活水平和地均就业人数轮流出现在第4或第5位;2009-2012年,前3位障碍因子发生较大变化,地均财政收入和人民生活水平成为阻碍土地利用绩效的主要因子;2013-2014年,前5位障碍因子变化较大,社会绩效成为制约土地利用绩效的主要子系统,改善人民生活水平、加强公共基础设施建设,探索节约化、集约化、高效化的土地利用方式和模式是提升安徽省土地利用绩效的重要出路;根据GM(1,1)模型预测结果,社会绩效、生态绩效和管理绩效在未来具有广阔的提升空间,安徽省在提高土地利用经济绩效的同时,应关注经济—社会—生态环境友好和谐发展,更加注重土地利用社会绩效、管理绩效特别是生态绩效的提升.该文的研究思路与方法可以为促进区域土地利用绩效提升提供现实依据.