一个二维的FDTD程序.docVIP

一个二维的FDTD程序 % 本程序实现2维TM波FDTD仿真 % 此程序用PML设置吸收边界条件 % FDTD_2D_kongqi_PML % 仅含有Ez,Hx,Hy分量 clear; clc; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% 1.初始化 T=200; % 迭代次数 IE=100; % JE=100; npml=8; % PML的网格数量 c0=3*10^8; % 波速 f=1.5*10^(9); % 频率 lambda=c0/f; % 波长 wl=10; dx=lambda/wl; dy=lambda/wl; pi=3.14159; dt=dx/(2*c0); % 时间间隔 epsz=1/(4*pi*9*10^9); % 真空介电常数 epsilon=1; % 相对介电常数 sigma=0; % 电导率 spread=6; % 脉冲宽度 t0=20; % 脉冲高度 ic=IE/2; % 源的X位置 jc=JE/2; % 源的Y位置 for i=1E+1; for j=1:JE+1; dz(i,j)=0; % z方向电荷密度 ez(i,j)=0; % z方向电场 hx(i,j)=0; % x方向磁场 hy(i,j)=0; % y方向磁场 ihx(i,j)=0;% ihy(i,j)=0; iz(i,j)=0; % z方向求和参量，频域卷积转化为时域求和 end; end; for i=2E; % for j=2:JE; ga(i,j)=1; end; end; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %PML参数的设置 for i=1E; gi2(i)=1; gi3(i)=1; fi1(i)=0; fi2(i)=1.0; fi3(i)=1.0; end for j=1:JE; gj2(j)=1; gj3(j)=1; fj1(j)=0; fj2(j)=1; fj3(j)=1; end for i=1:npml+1; %设置PML层中的参数 xnum=npml+1-i; xn=0.33*(xnum/npml)^3; gi2(i)=1.0/(1+xn); gi2(IE-1-i)=1/(1+xn); gi3(i)=(1-xn)/(1+xn); gi3(IE-1-i)=(1-xn)/(1+xn); xn=0.25*((xnum-0.5)/npml)^3; fi1(i)=xn; fi1(IE-2-i)=xn; fi2(i)=1.0/(1+xn); fi2(IE-2-i)=1/(1+xn); fi3(i)=(1-xn)/(1+xn); fi3(IE-2-i)=(1-xn)/(1+xn); end for i=1:npml+1; xnum=npml+1-i; xn=0.33*(xnum/npml)^3; gj2(i)=1.0/(1+xn); gj2(JE-1-i)=1/(1+xn); gj3(i)=(1-xn)/(1+xn); gj3(JE-1-i)=(1-xn)/(1+xn); xn=0.25*((xnum-0.5)/npml)^3; fj1(i)=xn; fj1(JE-2-i)=xn; fj2(i)=1.0/(1+xn); fj2(JE-2-i)=1/(1+xn); fj3(i)=(1-xn)/(1+xn); fj3(JE-2-i)=(1-xn)/(1+xn); end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% 2.迭代求解电场和磁场 for t=1:T; for i=2E; % 为了使每个电场周围都有磁场进行数组下标处理 for j=2:JE; dz(i,j)=gi3(i)*gj3(j)*dz(i,j)+gi2(i)*gj2(j)*0.5*(hy(i,j)-hy(i-1,j)-hx(i,j)+hx(i,j-1)); end; end; % 电场循环结束 pulse=sin(2*pi*f*t*dt); % 正弦波源 dz(ic,jc)=dz(ic,jc)+pulse; % 软源 for i=1E; % 为了使每个电场周围都有磁场进行数组下标处理 for j=1:JE; ez(i,j)=ga(i,j)* dz(i,j); %反映煤质的情况都是放到这里的 % iz(i,j)=iz(i,j)+gb(i,j)*ez(i,j) ; end; end; % 电荷密度循环结束 for j=1:JE; ez(