matlab写一个三维FDTD,并展示颜色图
时间: 2023-07-13 09:07:14 浏览: 235
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以下是一个简单的三维FDTD的MATLAB代码示例,并展示了一个颜色图:
```matlab
% 三维FDTD示例代码
% 定义常量
c0 = 3e8; % 光速
eps0 = 8.854e-12; % 真空介电常数
mu0 = 4*pi*1e-7; % 真空磁导率
% 定义空间参数
Lx = 1; % x方向长度
Ly = 2; % y方向长度
Lz = 3; % z方向长度
dx = 0.02; % x方向网格间距
dy = 0.02; % y方向网格间距
dz = 0.02; % z方向网格间距
Nx = Lx/dx; % x方向网格数
Ny = Ly/dy; % y方向网格数
Nz = Lz/dz; % z方向网格数
dt = 1/(2*c0/sqrt(1/dx^2+1/dy^2+1/dz^2)); % 时间步长
% 定义电磁场数组
Ex = zeros(Nx+1, Ny, Nz);
Ey = zeros(Nx, Ny+1, Nz);
Ez = zeros(Nx, Ny, Nz+1);
Hx = zeros(Nx, Ny+1, Nz+1);
Hy = zeros(Nx+1, Ny, Nz+1);
Hz = zeros(Nx+1, Ny+1, Nz);
% 定义介质参数
eps_r = ones(Nx, Ny, Nz); % 介电常数
mu_r = ones(Nx, Ny, Nz); % 磁导率
% 定义激励源
f0 = 100e6; % 激励频率
w0 = 2*pi*f0; % 激励角频率
t0 = 3/w0; % 激励峰值时间
sigma = 0.5/w0; % 激励高斯宽度
source = zeros(Nx, Ny, Nz); % 激励源数组
for i=1:Nx
for j=1:Ny
for k=1:Nz
source(i,j,k) = exp(-((i*dx-Lx/2)^2+(j*dy-Ly/2)^2+(k*dz-Lz/2)^2)/sigma^2)*sin(w0*(t0-dt)); % 高斯脉冲
end
end
end
% 定义边界条件
boundary = 'pml'; % 边界条件类型
if strcmp(boundary,'pml')
pml_thickness = 10*dx; % PML厚度
pml_strength = 1; % PML吸收强度(一般取1)
pml_m = 4; % PML阶数
pml_kappa = 1; % PML参数(一般取1)
pml_sigma_max = -(pml_m+1)*log(pml_strength)/(2*impedance0*pml_thickness); % PML最大电导率
pml_kappa_max = (pml_m+1)*pml_sigma_max/pml_kappa; % PML最大介电率
pml_sigma_x = zeros(Nx+1,Ny,Nz); % x方向电导率
pml_sigma_y = zeros(Nx,Ny+1,Nz); % y方向电导率
pml_sigma_z = zeros(Nx,Ny,Nz+1); % z方向电导率
pml_kappa_x = ones(Nx+1,Ny,Nz); % x方向介电率
pml_kappa_y = ones(Nx,Ny+1,Nz); % y方向介电率
pml_kappa_z = ones(Nx,Ny,Nz+1); % z方向介电率
for i=1:pml_thickness/dx
pml_sigma_x(i,:,:) = pml_sigma_max*(i*dx/(pml_thickness))^pml_m;
pml_sigma_x(Nx+1-i,:,:) = pml_sigma_max*(i*dx/(pml_thickness))^pml_m;
pml_kappa_x(i,:,:) = 1 + (pml_kappa_max-1)*((i*dx/(pml_thickness))^pml_m);
pml_kappa_x(Nx+1-i,:,:) = 1 + (pml_kappa_max-1)*((i*dx/(pml_thickness))^pml_m);
end
for j=1:pml_thickness/dy
pml_sigma_y(:,j,:) = pml_sigma_max*(j*dy/(pml_thickness))^pml_m;
pml_sigma_y(:,Ny+1-j,:) = pml_sigma_max*(j*dy/(pml_thickness))^pml_m;
pml_kappa_y(:,j,:) = 1 + (pml_kappa_max-1)*((j*dy/(pml_thickness))^pml_m);
pml_kappa_y(:,Ny+1-j,:) = 1 + (pml_kappa_max-1)*((j*dy/(pml_thickness))^pml_m);
end
for k=1:pml_thickness/dz
pml_sigma_z(:,:,k) = pml_sigma_max*(k*dz/(pml_thickness))^pml_m;
pml_sigma_z(:,:,Nz+1-k) = pml_sigma_max*(k*dz/(pml_thickness))^pml_m;
pml_kappa_z(:,:,k) = 1 + (pml_kappa_max-1)*((k*dz/(pml_thickness))^pml_m);
pml_kappa_z(:,:,Nz+1-k) = 1 + (pml_kappa_max-1)*((k*dz/(pml_thickness))^pml_m);
end
elseif strcmp(boundary,'periodic')
% 周期性边界条件
Ex(1,:,:) = Ex(Nx,:,:);
Ex(Nx+1,:,:) = Ex(2,:,:);
Ey(:,1,:) = Ey(:,Ny,:);
Ey(:,Ny+1,:) = Ey(:,2,:);
Ez(:,:,1) = Ez(:,:,Nz);
Ez(:,:,Nz+1) = Ez(:,:,2);
Hx(:,1,:) = Hx(:,Ny,:);
Hx(:,Ny+1,:) = Hx(:,2,:);
Hy(1,:,:) = Hy(Nx,:,:);
Hy(Nx+1,:,:) = Hy(2,:,:);
Hz(:,:,1) = Hz(:,:,Nz);
Hz(:,:,Nz+1) = Hz(:,:,2);
end
% 开始时间迭代
for n=1:1000
% 更新H场
Hx = Hx + (dt/(mu_r*mu0*dx)) .* (Ez(:,:,2:Nz+1)-Ez(:,:,1:Nz));
Hy = Hy + (dt/(mu_r*mu0*dy)) .* (Ex(:,1:Ny+1,2:Nz+1)-Ex(:,1:Ny+1,1:Nz));
Hz = Hz + (dt/(mu_r*mu0*dz)) .* (Ey(2:Nx+1,:,1:Nz+1)-Ey(1:Nx,:,1:Nz+1));
% 处理PML边界条件
if strcmp(boundary,'pml')
Hx(:,1:pml_thickness/dy,:) = Hx(:,1:pml_thickness/dy,:) ...
- (dt/(mu_r(:,1:pml_thickness/dy,:)*mu0*dy)) .* (Ez(:,1:pml_thickness/dy,2:Nz+1)-Ez(:,1:pml_thickness/dy,1:Nz)) ...
- pml_sigma_x(:,1:pml_thickness/dy,:) .* Hx(:,1:pml_thickness/dy,:);
Hx(:,Ny+1-pml_thickness/dy+1:Ny,:) = Hx(:,Ny+1-pml_thickness/dy+1:Ny,:) ...
- (dt/(mu_r(:,Ny+1-pml_thickness/dy+1:Ny,:)*mu0*dy)) .* (Ez(:,Ny-pml_thickness/dy+1:Ny,2:Nz+1)-Ez(:,Ny-pml_thickness/dy+1:Ny,1:Nz)) ...
- pml_sigma_x(:,Ny-pml_thickness/dy+1:Ny,:) .* Hx(:,Ny-pml_thickness/dy+1:Ny,:);
Hx(:,:,1:pml_thickness/dz) = Hx(:,:,1:pml_thickness/dz) ...
- (dt/(mu_r(:,:,1:pml_thickness/dz)*mu0*dz)) .* (Ey(2:Nx+1,:,1:pml_thickness/dz)-Ey(1:Nx,:,1:pml_thickness/dz)) ...
- pml_sigma_x(:,:,1:pml_thickness/dz) .* Hx(:,:,1:pml_thickness/dz);
Hx(:,:,Nz+1-pml_thickness/dz+1:Nz) = Hx(:,:,Nz+1-pml_thickness/dz+1:Nz) ...
- (dt/(mu_r(:,:,Nz+1-pml_thickness/dz+1:Nz)*mu0*dz)) .* (Ey(2:Nx+1,:,Nz-pml_thickness/dz+1:Nz)-Ey(1:Nx,:,Nz-pml_thickness/dz+1:Nz)) ...
- pml_sigma_x(:,:,Nz-pml_thickness/dz+1:Nz) .* Hx(:,:,Nz-pml_thickness/dz+1:Nz);
Hy(1:pml_thickness/dx,:,:) = Hy(1:pml_thickness/dx,:,:) ...
- (dt/(mu_r(1:pml_thickness/dx,:,:)*mu0*dx)) .* (Ez(2:Nx+1,:,1:Nz+1)-Ez(1:Nx,:,1:Nz+1)) ...
+ pml_sigma_y(1:pml_thickness/dx,:,:) .* Hy(1:pml_thickness/dx,:,:);
Hy(Nx+1-pml_thickness/dx+1:Nx,:,:) = Hy(Nx+1-pml_thickness/dx+1:Nx,:,:) ...
- (dt/(mu_r(Nx+1-pml_thickness/dx+1:Nx,:,:)*mu0*dx)) .* (Ez(Nx-pml_thickness/dx+1:Nx,:,1:Nz+1)-Ez(Nx-pml_thickness/dx+1:Nx,:,1:Nz+1)) ...
+ pml_sigma_y(Nx-pml_thickness/dx+1:Nx,:,:) .* Hy(Nx-pml_thickness/dx+1:Nx,:,:);
Hy(:,:,1:pml_thickness/dz) = Hy(:,:,1:pml_thickness/dz) ...
- (dt/(mu_r(:,:,1:pml_thickness/dz)*mu0*dz)) .* (Ex(:,2:Ny+1,1:pml_thickness/dz)-Ex(:,1:Ny,1:pml_thickness/dz)) ...
+ pml_sigma_y(:,:,1:pml_thickness/dz) .* Hy(:,:,1:pml_thickness/dz);
Hy(:,:,Nz+1-pml_thickness/dz+1:Nz) = Hy(:,:,Nz+1-pml_thickness/dz+1:Nz) ...
- (dt/(mu_r(:,:,Nz+1-pml_thickness/dz+1:Nz)*mu0*dz)) .* (Ex(:,2:Ny+1,Nz-pml_thickness/dz+1:Nz)-Ex(:,1:Ny,Nz-pml_thickness/dz+1:Nz)) ...
+ pml_sigma_y(:,:,Nz-pml_thickness/dz+1:Nz) .* Hy(:,:,Nz-pml_thickness/dz+1:Nz);
Hz(1:pml_thickness/dx,:,:) = Hz(1:pml_thickness/dx,:,:) ...
- (dt/(mu_r(1:pml_thickness/dx,:,:)*mu0*dx)) .* (Ey(1:Nx+1,2:Ny+1,1:Nz+1)-Ey(1:Nx,2:Ny+1,1:Nz+1)) ...
- pml_sigma_z(1:pml_thickness/dx,:,:) .* Hz(1:pml_thickness/dx,:,:);
Hz(Nx+1-pml_thickness/dx+1:Nx,:,:) = Hz(Nx+1-pml_thickness/dx+1:Nx,:,:) ...
- (dt/(mu_r(Nx+1-pml_thickness/dx+1:Nx,:,:)*mu0*dx)) .* (Ey(Nx-pml_thickness/dx+1:Nx,2:Ny+1,1:Nz+1)-Ey(Nx-pml_thickness/dx+1:Nx,2:Ny+1,1:Nz+1)) ...
- pml_sigma_z(Nx-pml_thickness/dx+1:Nx,:,:) .* Hz(Nx-pml_thickness/dx+1:Nx,:,:);
Hz(:,:,1:pml_thickness/dy) = Hz(:,:,1:pml_thickness/dy) ...
- (dt/(mu_r(:,:,1:pml_thickness/dy)*mu0*dy)) .* (Ex(1:Nx+1,:,2:Nz+1)-Ex(1:Nx+1,:,1:Nz)) ...
+ pml_sigma_z(:,:,1:pml_thickness/dy) .* Hz(:,:,1:pml_thickness/dy);
Hz(:,:,Nz+1-pml_thickness/dy+1:Nz) = Hz(:,:,Nz+1-pml_thickness/dy+1:Nz) ...
- (dt/(mu_r(:,:,Nz+1-pml_thickness/dy+1:Nz)*mu0*dy)) .* (Ex(1:Nx+1,:,Nz-pml_thickness/dy+1:Nz)-Ex(1:Nx+1,:,Nz-pml_thickness/dy+1:Nz)) ...
+ pml_sigma_z(:,:,Nz-pml_thickness/dy+1:Nz) .* Hz(:,:,Nz-pml_thickness/dy+1:Nz);
end
% 更新E场
Ex(:,2:Ny,:) = Ex(:,2:Ny,:) + (dt/(eps_r(:,2:Ny,:)*eps0*dy)) .* (Hz(:,2:Ny+1,:)-Hz(:,1:Ny-1,:));
Ex(:,Ny,:) = Ex(:,Ny,:) + (dt/(eps_r(:,Ny,:)*eps0*dy)) .* (Hz(:,1,:)-Hz(:,Ny,:));
Ey(2:Nx,:,:) = Ey(2:Nx,:,:) + (dt/(eps_r(2:Nx,:,:)*eps0*dx)) .* (Hz(2:Nx+1,:,:)-Hz(1:Nx-1,:,:));
Ey(Nx,:,:) = Ey(Nx,:,:) + (dt/(eps_r(Nx,:,:)*eps0*dx)) .* (Hz(1,:,:)-Hz(Nx,:,:));
Ez(:,:,2:Nz) = Ez(:,:,2:Nz) + (dt/(eps_r(:,:,2:Nz)*eps0*dz)) .* (Hy(:,:,2:Nz+1)-Hy(:,:,1:Nz-1));
Ez(:,:,Nz) = Ez(:,:,Nz) + (dt/(eps_r(:,:,Nz)*eps0*dz)) .* (Hy(:,:,1)-Hy(:,:,Nz));
% 添加激励源
Ez(:,:,1) = Ez(:,:,1) + source(:,:,n);
% 显示模拟结果
if mod(n,10)==0
slice_index = round(Nx/2);
slice = reshape(sqrt(abs(Ex(slice_index,:,:)).^2+abs(Ey(slice_index,:,:)).^2+abs(Ez(slice_index,:,:)).^2),[Ny,Nz]);
imagesc(slice');
axis equal;
axis off;
colormap(jet);
colorbar();
drawnow;
end
end
```
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