共查询到17条相似文献,搜索用时 187 毫秒
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采用边界元法求解径流式叶轮机械子午流动问题,通过新编制的程序,对三种离心式压气机进行了计算,计算结果与实验数据比较接近,展示边界元法具有较好的实用。 相似文献
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采用二次等参数边界元对某烟气透平轮盘的温度场进行了计算。结果表明,边界元法除具有计算精度高、计算前处理简便等优点外,在研究多域问题时有独特的方便之处,是一种先进的数值计算方法。 相似文献
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本文用二维边界元法计算了混流式水轮机全部引水部件的二维势流流场.提出了引水部件二维势流模型.在边界元计算中,采用了常数单元积分的解析公式,并将库塔条件直接引入了边界元方程中.避免了复杂多连通域中库塔条件的多重迭代.计算结果与一个模型实验结果吻合较好.图5参6 相似文献
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声边界元法在内燃机机体辐射噪声预报中的应用研究 总被引:5,自引:1,他引:4
本结合振动有限元法和声边界元法建立了内燃机机体辐射噪声预报模型,开发了相应的通用计算程序,复式声强测量结果表明该计算程序有较高的计算精度,是低噪声内燃机设计的基础。 相似文献
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采用边界元法求解径流式叶轮机械子午流动问题。通过所编制的程序,对三种离心式压气机进行了计算。计算结果与实验数据比较接近,展示边界无法具有较好的实用性。图5参5 相似文献
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边界元法是一种新的正在发展中的数值计算方法,其主要优点是仅需在物体表面离散网格,而且计算精度较高,并可广泛地应用于许多领域。本文从热传导方程出发,介绍了三维环界法的理论和数值计算方法,并在IBMPC/XT 微型计算机上开发了可解工程实际问题的三维边界元程序,同时对国产135系列柴油机活塞进行了分析计算及试验研究,结果表明,边界元法是一种有效的数值计算方法。 相似文献
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在推导出轴对称势问题的基本解及边界积分方程的基础上,本文采用二次等参插值函数进行离散,形成轴对称热传导问题的边界元方程,编制了包含三类边界条件在内的轴对称边界元分析程序,最后对195柴油机活塞温度场进行了计算。结果表明,边界元法分析活塞温度场,不仅计算准备工作量比有限元大为减少,而且精度高、计算时间短,尤其采用二次等参元后,其优点更加突出。 相似文献
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柴油机活塞热应力轴对称边界元数值分析 总被引:1,自引:0,他引:1
本在推出轴对称热应力问题的边界积分方程的基础上采用2次等参插值函数将边界积分方程离散为边界元方程,进一步运用开发的程序分析了某135柴油机活塞的热应力场,分析结果表明边界元法在动力机械零部件热应力问题的分析中,与其它数值方法相比,具有计算精度高,数据准备简单和计算时间少等独特的优点。 相似文献
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本文从三维瞬态热问题的边界积分方程及基本解出发、推导出轴对称瞬态热问题的边积分方程及基本解、然后离散形成边界元方程。编程对瞬态温度例进行验证分析后,对K150E柴油机缸盖简化成轴对称模型后的起动工况温度场进行了分析计算,结果表明推导出的公式是可行的,具有较高的精度和数值稳定性,能应用于复杂的轴对称回转体的瞬态温度场分析。 相似文献
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基于随机边界元法的连杆可靠性分析 总被引:1,自引:0,他引:1
在确定性边界元数值方法的基础上,通过采用非统计逼近的处理方法建立了基于一阶二次矩法的二维弹性随机边界元数值方法的基本方程和可靠度分析公式,进一步运用开发的相应软件分析了内燃机连杆小头的应力数字特征量,并与采用蒙特卡洛随机模拟方法对连杆小头得到的随机应力数字特征量进行了比较,验证了本提出的方法的可靠性。在此基础上,对连杆小头疲劳强度可靠度进行了计算,结果表明本提出的方法不仅用于复杂结构的可靠度进 相似文献
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J. Chatterjee D.P. Henry F. Ma P.K. Banerjee 《International Journal of Heat and Mass Transfer》2008,51(5-6):1439-1452
In this work, an efficient boundary element formulation has been presented for three-dimensional steady-state heat conduction analysis of fiber reinforced composites. The cylindrical shaped fibers in the three-dimensional composite matrix are represented by a system of curvilinear line elements with a prescribed diameter which facilitates efficient analysis and modeling together with the reduction in dimensionality of the problem. The variations in the temperature and flux fields in the circumferential direction of the fiber are represented in terms of a trigonometric shape function together with a linear or quadratic variation in the longitudinal direction. The resulting integrals are then treated semi-analytically which reduces the computational task significantly. The computational effort is further minimized by analytically substituting the fiber equations into the boundary integral equation of the material matrix with hole, resulting in a modified boundary integral equation of the composite matrix. An efficient assembly process of the resulting system equations is demonstrated together with several numerical examples to validate the proposed formulation. An example of application is also included. 相似文献
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Xiao-Wei Gao Yong-Tong Zheng Nicholas Fantuzzi 《Numerical Heat Transfer, Part B: Fundamentals》2020,77(6):441-460
AbstractIn this article, a completely new numerical method called the Local Least-Squares Element Differential Method (LSEDM), is proposed for solving general engineering problems governed by second order partial differential equations. The method is a type of strong-form finite element method. In this method, a set of differential formulations of the isoparametric elements with respect to global coordinates are employed to collocate the governing differential equations and Neumann boundary conditions of the considered problem to generate the system of equations for internal nodes and boundary nodes of the collocation element. For each outer boundary or element interface, one equation is generated using the Neumann boundary condition and thus a number of equations can be generated for each node associated with a number of element interfaces. The least-squares technique is used to cast these interface equations into one equation by optimizing the local physical variable at the least-squares formulation. Thus, the solution system has as many equations as the total number of nodes of the present heat conduction problem. The proposed LSEDM can ultimately guarantee the conservativeness of the heat flux across element surfaces and can effectively improve the solution stability of the element differential method in solving problems with hugely different material properties, which is a challenging issue in meshfree methods. Numerical examples on two- and three-dimensional heat conduction problems are given to demonstrate the stability and efficiency of the proposed method. 相似文献