一种计算活塞环自由型线的新方法

推导了在给定压力分布ｐ（θ）下，活塞环自由型线所应满足的微分方程，并给出求解方程的一种新计算方法。实例计算表明，此种数值计算方法具有精度高、速度快、给出数据齐全等优点，而且对任何压力分布ｐ（θ）均可适用。     

并联管组中单相流体的水动力推进算法

以不可压流体的连续方程和动量方程为基础,将分支管流速作为未知量,建立了推进算法的基本方程,提出并联管组中单相流体的水动力推进算法。在推进计算每一步中,只需要求解关于分支管流速的代数方程,逐管推进并迭代至满足给定的边界条件。计算过程简单,易于收敛。计算结果表明,这是一种简捷有效的并联管组水动力新算法。图5参9     

用元素扩散方程和化学平衡热力计算的方法求解多组分反应流场

提出了一种新的方法来计算多组分化学反应流场。它首先引入了元素的分布方程，然后根据化学平衡的热力计算方法求解每一位置的组分及温度。这样，在计算低速流场时，就避免了处理化学反应源项引起的数值计算过程中的方程刚性问题，也减少了组分方程的数量。计算结果表明，这种方法的计算结果比EBU模型的计算结果更好的反应了物质热解离的情况。     

反弯角达30℃离心压气机叶轮内部流场的数值研究及改型设计

采用一种粘性体积力方法简化三维Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程的求解过程，计算了Ｋｒａｉｎ叶轮内部流场。使用Ｈ型网格离散微分方程，离散后的方程使用显式时间推进的有限体积方法求解。还以Ｋｒａｉｎ离心压气机叶轮为原型，对这个叶轮的叶型形状进行局部修改，根据计算结果发现如何修改叶片形状才能达到改善叶轮性能的目的。     

反弯角达30°离心压气机叶轮内部流场的数值研究及改型设计

采用一种粘性体积力方法简化三维Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ 方程的求解过程，计算了Ｋｒａｉｎ 叶轮内部流场。使用Ｈ 型网格离散微分方程，离散后的方程使用显式时间推进的有限体积方法求解。还以Ｋｒａｉｎ 离心压气机叶轮为原型，对这个叶轮的叶型形状进行局部修改，根据计算结果发现如何修改叶片形状才能达到改善叶轮性能的目的。     

非正交曲线系下数值模拟及PDA测量模化炉内湍流流场

构造强守恒形式N－S离散方程组，耦合求解速度和压力修正方程，κ-ε双方程模型模拟湍流粘性。在方程离散中，采用以加权平均方法计算胞元界面上不连续的几何因子，以保持坐标转换的光滑性；以迭代方式考虑交错压力梯度项，并对常规形式压力方程结果进行二次修正。计算结果表明，针对局部非光滑且远离正交性的炉内网格体系，上述特殊数值方法对保证求解精度和收敛性具有关键作用。采用3D－PDA（三维激光多谱勒固粒运动分析仪）对670t/h四角切圆炉的1：20模型内冷态流场进行了测量。数值模拟结果与实验结果基本吻合。     

竖壁自然对流换热系数计算研究

本文对竖壁自然对流求解提出了新的条件假设，给出了其合理的控制方程，通过计算，得出了自然对流计算的新准则关系式，拓展准则的适用范围，可以为工程精计算采用。     

用欧拉方程,N—S方程求解蒸汽透平通流部分全三元流场的计算程序及应用

分别介绍了用欧拉方程，Ｎ－Ｓ方程求解蒸汽透平通流部分全三元流场的计算程序及应用，通过对某一实际蒸汽透平级及级组的计算，证明两种计算方法都是成功的，计算程序是正确可信的。     

低压给水加热器变工况优化热力计算方法

文章从传热学的角度提出一种适用于低压加热器变工况运行时的优化计算方法。介绍了低压加热器的功能原理及传热过程。分析了给定端差计算法的局限性。构建了优化的低压加热器内部传热理论模型并对其求解过程进行了描述。给出了定面积和定端差2种不同情况下,加热器参数与给水参数的变化关系曲线。根据计算结果对加热器在变工况条件下运行时的参数特性进行了分析。     

边界元法在气冷涡轮叶栅气热耦合计算中的应用

将边界元计算方法应用到三维N-S方程求解程序中,流体部分采用有限差分法求解N-S方程,边界元法求解固体区域热传导方程。开发气热耦合计算程序对NASA-MarkII高压气冷涡轮叶栅热环境进行气热耦合分析。利用边界元法特有的优势(降维、解析与离散相结合的特点),避免了固体区域的网格生成和内部节点求解工作,提高了计算精度。结果表明,耦合计算程序能够高效、准确求解多场的气热耦合问题,计算结果与实验结果吻合的较好,二者平均误差为3%。     

DISCONTINUITIES IN GENERALIZED THERMO-VISCOELASTICITY UNDER FOUR THEORIES

A model of the equations of generalized thermoviscoelasticity for isotropic media is given. The formulation is applied to the generalized thermoelasticity theories—Lord–Shulman, Green–Lindsay, and Chandrasekharaiah and Tzou—as well as to the dynamic coupled theory. The state-space approach is adopted for the solution of the one-dimensional problem of plane distribution of heat sources. The Laplace transform technique is used. The expansions of the stress component, the temperature increment, and the displacement, in Laplace transform domain, in power series, and the exact inversions for arbitrary time, are given. The jump discontinuities are calculated for the four theories and the kinematic conditions of compatibility are verified. Numerical results are given and illustrated graphically by employing the numerical method for the inversion of the Laplace transforms. Comparisons are made with the results predicted by the four theories.     

Generalized Theory of Thermoelastic Diffusion for Anisotropic Media

The equations of generalized thermoelastic diffusion, based on the theory of Lord and Shulman with one relaxation time, are given in anisotropic media. A variational principle for the governing equations is obtained. Then we show that the variational principle can be used to obtain a uniqueness theorem under suitable conditions. A reciprocity theorem for these equations is given. The obtained results are valid for some special cases that can be deduced from our generalized model.     

A study of flexibility factors of integrally reinforced shell to shell intersections

The results of flexibility tests on 32 test samples (four unreinforced shell to shell intersections or stub-ins, 14 integrally reinforced weld-on connections, ten integrally reinforced contoured inserts, and four pad-reinforced connections) are presented in this report. The flexibility factors of these connections were experimentally determined. The experimental values are compared to predicted values given in ASME code, Section III, Subsection NB. Recommended equations for flexibility factors are given for the cases where experimental values do not agree with the predictions using the code equations.     

THERMOELASTIC PROBLEM FOR A GRIFFITH CRACK IN A PLATE WITH TEMPERATURE-DEPENDENT PROPERTIES UNDER A LINEAR TEMPERATURE DISTRIBUTION

This paper is concerned with a method for calculating the thermal-stress distribution in a plate exhibiting temperature-dependent properties. Using the perturbation method, general equations for the displacements are found. The equations can be solved by using four displacement functions. Following this method, a solution is derived for calculating the stress intensity factor for a Griffith crack in a temperature-sensitive plate under a linear temperature distribution, where we assume that the temperature field is not disturbed by the crack. (Under these conditions, if a plate is temperature-insensitive, the stress intensity factor for the crack is zero.) In this case, whether the stress intensity factor is zero or not depends only on the temperature variation of the coefficient of thermal expansion. A numerical example is given for a plate made of steel.     

On gevrey asymptotics for some nonlinear integro-differential equations

We construct formal power series solutions of nonlinear integro-differential equations for given initial conditions which are holomorphic functions on a strip in the complex plane C. We give sufficient conditions on the shape of the equations and on the initial conditions under which there exist actual holomorphic solutions which are Gevrey asymptotic to the given formal series solutions with respect to the time variable on sectors in C. We get 1−Gevrey asymptotic expansions on sectors of opening less than π but not 1−summability as it is the case for linear partial differential equations. Moreover, our approach yields global analytic solutions of these equations in both time and space variables.     

气门调整盘塑性成形工艺

介绍了气门调整盘锻件的4种塑性成形工艺方案,分析了它们的优缺点,并着重分析了其中两种优化工艺方案模具的设计要点。     

正交各向异性媒质中电磁场的有限元法

针对非均匀正交各向异性媒质中的电磁场问题,给出了相应的约束方程和定解条件;对边值问题及其变分问题的等价进行了证明,在此基础上建立了相应的有限元方法,并对非均匀正交各向异性媒质中的有限元方程进行了编程计算。     

The Refined Theory of Thermoelastic Plane Problems

Based on thermoelastic theory, various two-dimensional equations and solutions for plane problems have been deduced systematically and directly from thick plate theory by using Biot's solution and Lur'e method without ad hoc assumptions. These equations and solutions can be used to construct the refined theory for the plane problems. In the case of homogeneous boundary conditions, the exact governing differential equations and solutions for the plate are derived, which consist of four governing differential equations. It is important note that the refined theory is consistent with the decomposition theorem by Gregory. In the case of non-homogeneous boundary conditions, the approximate governing differential equations and solutions for the plate are accurate up to the second-order terms. The correctness of the stress assumptions in the classic plane stress problems is revised.     

Theory of Generalized Micropolar Thermoelastic Diffusion Under Lord–Shulman Model

The general equations of motion and constitutive equations, based on the theory of Lord–Shulman with one relaxation time, are derived for a general homogeneous anisotropic medium with a microstructure, taking into account the effects of heat and diffusion. A variational principle for the governing equations is obtained. Then we show that the variational principle can be used to obtain a uniqueness theorem under suitable conditions. A reciprocity theorem for these equations is given. The obtained results are valid for some special cases which can be deduced from our generalized model.     

空气纵掠带顶端间隙的非标准错列肋片簇的换热及阻力性能的研究

利用萘升华技术，在Ｒｅ＝２０００－２２０００的范围内对有顶端间隙的非标准错列肋片簇的传热（质）及阻力特性进行了实验研究，给出了各个肋片位错情况下，Ｓｈｅｒｗｏｏｄ数及阻力系数ｆ随Ｒｅｙｎｏｌｄｓ数变化的拟合关系式，并综合分析了肋片位错对非标准错列肋片簇的传质（换热）及阻力性能的影响，所得结论可供工程设计时参考。