-recursive-

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)

数值计算的算法，采用c++实现，移植容易，一定能够用。(Data processing)

说明：  计算潜在蒸发，方法为彭曼法，需要气温、日照、风速等资料，具体详见程序界面(Pe calculation)

EDFA的掺铒光纤长度模拟计算，附3篇相关论文，330mw的980nm泵泵浦，3db的泵浦吸收，12m最佳长度已经的到验证，可作为EDFA设计参考 (EDFA erbium-doped fiber length simulation of three related papers, 330mw of 980nm pump pump pump 3db absorption 12m optimum length has been to verify, can be used as the EDFA design reference)

Orthogonal Polynomials Approximation 数值分析，计算正交基多项式的系数 (Given a function f and a set of m >0 distinct points . You are supposed to write a function to approximate f by an orthogonal polynomial using the exact function values at the given m points with a weight assigned to each point . The total error must be no larger than a given tolerance. Format of function int OPA( double (*f)(double t), int m, double x[], double w[], double c[], double*eps ) where the function pointer double (*f)(double t) defines the function f int m is the number of points double x[] contains points double w[] contains the values of a weight function at the given points x[] double c[] contains the coefficients of the approximation polynomial double*eps is passed into the function as the tolerance for the error, and is supposed to be returned as the value of error. The function OPA is supposed to return the degree of the approximation polynomial. Note: a constant Max_n is defined so that if the total error is still not small enough when n = Ma)

一个对Fluent中k-e湍流模型的修正udf程序，c语言(One pair ke turbulence model in Fluent udf amendment procedures)

内插高程点，CASS不提供插求高程点功能，我们手工输入容易出错，且极度不方便，。 此程序用VBA编写，界面操作，按设定的比例自动计算需内插的个数并注记。(Interpolated elevation points)

给出了高斯消元的代码，和程序页面，方便快捷(The code and program page of Gauss elimination are given, which is convenient and quick.)

单元刚度矩阵，用于计算三单元刚度矩阵，输出刚度矩阵(Element stiffness matrix is ​ ​ used to calculate the three-element stiffness matrix, the output stiffness matrix)

一圆形游泳池如图所示，现在需在其周围建一圆形过道，并在其四周围上栅栏。 栅栏价格为35元/米，过道造价为20元/平方米。 过道宽度为3米， 游泳池半径由键盘输入。 要求编程计算并输出过道和栅栏的造价。(A circular pool as shown in figure, now in its built around to a circular corridor, and in its 4 around on the fence. The fence for 35 yuan/m price, corridor cost for 20 yuan/square metre. Aisle width is 3 meters, The radius of the swimming pool by keyboard input. Demand and output programming calculation of corridor and the cost of the fence. )