Eigenvalue approach to fractional order generalized thermoelasticity with line heat source in an infinite medium

Applying the eigenvalue approach method along with Laplace transform, a general solution scheme for the thermoelastic deformation of an unbounded transversely isotropic medium has been developed on fractional order generalized thermoelasticity with an instantaneous heat source. Solution has been achieved in Laplace transform domain for the perturbed temperature field and other field variables. Several graphs have been presented, and analyses of the results have been made.     

燃机运行中对排烟温度分散度监视的重要性

在燃机运行过程中对排温度分散度的监视非常重要。本文分析了造成排烟温度分散度大的一般原因,阐述了排烟温度分散度大对燃机热部件的危害,同时还对控制系统中排烟温度分散度允许值的计算方法进行了简单的说明,最后对在运行过程中如何对排烟温度分散度进行监视进行了说明。     

Two-Temperature Generalized Thermoelasticity with Variable Thermal Conductivity

In this work, the consideration of variable thermal conductivity as a linear function of temperature has been taken into account in the context of two-temperature generalized thermoelasticity (Youssef's model). The governing equations have been derived and used to solve the one-dimensional problems of an elastic half-space. The governing equations have been cast into a matrix form by using Bahar–Hetnarski method, and Laplace transform is used to get the general solution for any set of boundary conditions. The solution has been applied for a thermally shocked medium that has no strain on its bounding plane. The numerical inversion of the Laplace transform has been calculated by using the Riemann-sum approximation method. The distribution of the conductive temperature, the thermo-dynamical temperature, the strain, the displacement, and the stress have been shown graphically with some comparisons.     

基于基元叶栅法的轴流式压气机变工况性能计算模型

基于基元叶栅法,建立了轴流式压气机的变工况计算模型,并采用变比热公式计算空气的热力参数;绘制了压比、等熵效率、折合耗功率和折合出口总温的通用特性曲线;计算了压气机的运行工况线。在此基础上,确定了压气机的喘振边界线。定量计算了IGV对压气机通用特性曲线的影响。建模过程中,考虑了空气相对湿度对压气机通用特性曲线的影响。算例表明,该模型精度较高,能够对具有IGV的压气机进行变工况计算。本文所做工作为进一步研究压气机的变工况性能奠定了基础。     

Free vibration analysis of rotating cylindrical shells using discrete singular convolution technique

Free vibration analysis of rotating cylindrical shells is presented. Discrete singular convolution (DSC) method has been proposed for numerical solution of vibration problem. The formulations are based on Love's first approximation shell theory, and include the effects of initial hoop tension and centrifugal and Coriolis accelerations due to rotation. Frequencies are obtained for different types of boundary conditions and geometric parameters. In general, close agreement between the obtained results and those of other researchers has been found.     

标准件、通用件协同管理数据库系统开发与应用

以产品数据管理的协同设计系统TeamCenter 2007为研究平台,以商用车所应用的标准件和通用件为主要研究对象,对基于TeamCenter系统的网络环境下的商用车标准件和通用件数据库的构建方法进行了深入的研究,完成了上汽商用车标准件、通用件协同管理数据库系统的开发。该系统已在上汽商用车技术中心与上柴公司新产品开发中得到有效应用。     

Exact solution of the transient forced convection energy equation for timewise variation of inlet temperature

An exact solution to the equation of transient forced convection for time varying inlet temperature with a general, space dependent boundary condition of an incompressible laminar forced convection heat transfer with fully developed flow between two parallel plates is given. The finite integral transform technique has been used as the method of analysis. Analytical results for laminar and turbulent flow are presented. The results are confirmed experimentally by the frequency response method.     

通用小型汽油机工况法燃油消耗率测试方法解析

GB/T 37692-2019《非道路移动机械用小型点燃式发动机工况法燃油消耗率限值与测量方法》标准于2019年6月4日发布,将于2020年1月1日正式实施。本文根据标准内容,从试验条件、仪器设备、试验工况的选择、试验流程和数据计算等要点,对通用小型汽油机工况法燃油消耗率测试方法要求进行了解读,为检测机构和企业进行通用小型汽油机油耗测试提供参考。     

固定结构的气体喷射器效率研究

具有喷射器原理的装置在很多领域上应用,其一般设计早已被人们所掌握,但对如何提高其效率的研究不太多。经过大量经验和计算研究和计算研究,探讨出影响喷射器效率的重要因素,提出了在喷射器结构一定的情况下,改变喷口在吸入管的位置进一步提高喷射器效率的方法,该方法可以使喷射器效率最多提高10个百分点以上。     

柴油机智能故障诊断仪的硬件设计

介绍了一种基于CAN总线的柴油机智能故障诊断仪的硬件设计,通过对高性能处理器PIC18F458特点的分析,描述了诊断仪系统的一般硬件结构原理、功能和作用,以及其软件结构和设计方法,并通过了实测验证。     

Modelling compression pressure distribution in fuel cell stacks

A general purpose 3D finite element method model has been developed for the estimation of the compression pressure distribution in fuel cell stacks. The model can be used for the optimisation of any type of fuel cell structure at any temperature. The model was validated with pressure sensitive film measurements using PEFC stack components that had low rigidity and were highly deformable.     

Instantaneous distribution of global and diffuse radiation on horizontal surfaces

The aim of this paper is to obtain a general expression for estimating both the instantaneous global and diffuse radiations on horizontal surfaces from the respective daily values. The proposed expression is a modified Gaussian distribution with two parameters which take into account its width and the asymmetries between morning and afternoon hours. The performance of the method has been tested by comparing the theoretical hourly results with the experimental data of six actinometric stations with different geographical location and climatic conditions. The comparison has shown that the method here proposed is accurate for both the diffuse and global radiation.     

气垫式调压室安全水深合理取值研究

对于气垫式调压室，目前大多定性地认为其安全水深应大于常规调压室的取值。以常规调压室安全水深取2m时的安全性和经济性作为参照系。通过对涌波幅值、稳定运行水位异常变化值以及体型结构参数等与安全水深关系的比较分析．提出了气垫式调压室安全水深的取值方法及合理取值范围。     

某燃气轮机叶片-轮盘耦合振动特性研究

首先介绍了循环对称结构固有特性的计算方法,在此基础上建立了叶片-轮盘耦合系统振动固有特性计算分析模型,并利用大型通用有限元分析软件ANSYS对某燃气轮机叶片-轮盘耦合结构进行分析计算。最后根据分析结果总结概括了叶盘耦合系统的振动特点,为其寿命及可靠性计算提供了数值依据。     

CFD技术在汽轮机通流设计中的应用

简要介绍了计算流体力学（CFD）技术的发展与数值方法。列举CFD通用分析软件应用于汽轮机通流级分析的几个典型算例。分析结果表明,应用先进的计算流体力学（CFD）技术进行汽轮机的通流设计,可有效提高设计机组的通流级效率和设计质量。CFD技术在汽轮机通流设计中的应用缩短了产品开发周期,节约了开发成本。     

类热机结构优化特征及其论证

在已有热机构形优化特性以及类热机装置的构形优化特性分析基础上,将类热机模型推广到一般的传输过程模型,通过变分法导出了一般传输过程的构形优化准则,证明了对于线性传输模型,在有限尺寸约束条件下,传输过程（或装置）熵产最小时,传递系数在区域内等分是其基本特征。同时介绍了传输过程的构形优化在类热机装置分析和广义热力学优化理论研究中的应用,初步验证了本文提出的构形优化特征,并简要阐述其应用发展方向。     

复杂换热器系统的动态特性计算

介绍了在国产２００ｔ／ｈ循环流化床锅炉建模与仿真工作中开发的复杂换热器系统动态特性的计算方法。该方法以近似解析解方法为基础,大大提高了运算速度,并解决了计算的不收敛问题,解耗算法的采用,令冷,热工质的平衡计算得以分离,从根本上避免了迭代计算。借助近似解析解方法和解耦算法,建立了一套通用的换热器动态特性模块化计算方法,从而为复杂换热器系统的动态特性计算提供了一个通用性强而且高效、简便的方法。     

Closure of non-equilibrium volume-averaged energy equations in high-conductivity porous media

A formulation for closure of the volume-averaged energy equations under local thermal non-equilibrium conditions has been proposed, providing a general method for obtaining the relevant effective properties for high-conductivity porous materials. The method requires numerical solution of the flow field, as well as closure problems, over a representative volume of porous media. This study considers an array of highly conductive circular cylinders for which all relevant effective properties are obtained. Comparisons are made to results in literature for low Reynolds numbers, while results at higher Reynolds numbers are presented to provide insight into the effects of inertia on the effective properties.     

Numerical simulation of boiling enhancement on a microstructured surface

Significant efforts have been made to augment nucleate boiling by surface modification with micro-machined structures, but a general predictive approach for heat transfer enhancement has not yet been developed. In this work, complete numerical simulations are performed for boiling enhancement on a microstructured surface by employing the sharp-interface level-set method, which is modified to handle the contact angle and the evaporative heat flux from the liquid microlayer on an immersed solid surface. The effects of cavity diameter and surface modification such as concentric grooves and multi-step cavities on bubble growth and boiling heat transfer are investigated.