digital5

自己写了一个二维Euler方程的间断有限元程序 上次发了一个三角形单元的程序 因为不是曲边单元 所以在圆柱后面容易形成涡 现在把程序改为曲边四边形单元了 没有涡出现 单元是8节点四边形单元 节点编号顺序是 1 5 2 6 3 7 4 8 也就是四个角点依次 是1 2 3 4 然后是边的中点编号 5 6 7 8. 时间推进采用 Runge-Kutta 方法 数值通量采用全局Lax-Friedrichs通量 仍然不能捕捉激波 因为没有做重构或者加人工粘性 等这个做出来了 再发一次。 程序没有进行优化 比如说内存的消耗没有优化 比如直边单元的边界积分仍然采 用了曲边的积分方法 增加了计算量 比如面积分、线积分都是采用的是Gauss- Legendre-Lobatto积分 积分精度会比一般的Gauss-Legendre积分精度低一阶 等 等问题。 二维的 纯属交流性质 就没有考虑这些问题 ^_^ 如果物面全部是直边 那么只要改变一个参数N 就可以获得不同的计算精度 且具 有谱精度 因为单元的节点是Gauss-Legendre-Lobatto积分点。 其实就是谱元法 （物面是曲边的情况我不清楚是不是也可以通过提高基函数的阶数 也就是增加N 来提高计算精度）(Wrote a two-dimensional Euler equations with discontinuous finite element program Last made ​ ​ a triangular element of the program, not curved edge unit is so easy to form a vortex in the cylinder behind the Program to curved edge quadrilateral element vortices appear Unit is the order of 8-node quadrilateral element node number is 15,263,748 which is the four corners of the points in turn Is 1234 and then the side of the midpoint of the number 5678. Time promote the use of Runge-Kutta method Numerical flux of the overall situation of Lax-Friedrichs, flux Still can not capture the shock wave did not do the reconstruction or artificial viscosity do it Zaifayici. The program is not optimized for example, memory consumption is not optimized such as straight-edge boundary integral of the unit is still mining Integral method to increase the amount of computation such as surface integral with a curved edge, the line integral using the Gauss- The Legendr)

说明：  一个用C语言编写的求混沌序列的源程序,挺好的!(a C language for the chaotic sequence of the source, very good!)

六轴工业机器人的逆运动学,采用VC++进行编程自动求解(inverse of 6-dof industrial robot)

是CA算法的test程序，用于描述微观枝晶长大的代码！(CA algorithm is the test procedure, used to describe the micro-dendrites grew up in the code!)

用C++编写的一维和二维快速傅里叶变换程序(Prepared with C++ one-dimensional and two-dimensional fast Fourier transform procedure)

多物理场耦合软件采用有限元方法模拟rtfindgen(Coupled multi-physics simulation software using the finite element method rtfindgen)

通过具有随机结构参数的四分之一车辆模型研究了具有不确定性结构参数的车辆在受到来自道路的随 机激励作用下的振动响应问题。将簧上质量、簧下质量、悬挂阻尼、悬挂刚度以及轮胎刚度均认为是随机变量。将路面的不平整引起的对车辆的激励看作高斯随机过程并通过简单指数功率谱密度来建立力学模型。(By a quarter vehicle model with random parameters studied vehicle structure uncertain structural parameters of the vibration by the random excitation the road response under question. The sprung mass, unsprung mass, suspension damping, suspension stiffness and rigidity of the tire are considered to be random variables. The excitation caused by uneven road vehicle regarded as Gaussian random process and to create a mechanical model of a simple exponential power spectral density.)

　禁忌搜索算法是一种全局性邻域搜索算法，模拟人类具有记忆功能的寻优特征。它通过局部邻域搜索机制和相应的禁忌准则来避免迂回搜索，并通过破禁水平来释放一些被禁忌的优良状态，进而保证多样化的有效探索，以最终实现全局优化(Tabu search algorithm)

说明：  这是LU分解法求线性方程组的资料，讲解了LU分解的原理及过程，非常实用(LU decomposition seeking linear equations to explain the principles and process of the LU decomposition, very practical)

计算日期时间，可以显示不同颜色，主要用以计算上班日期，换班日期，十分方便。(Daliy Calc)