%思路:1.计算一个电流线圈的磁场
% 2.将一侧磁场与另一侧叠加
I=2; %电流
R=2.5; %线圈半径
N=20;
Nx=81;Ny=81;
u=4*pi*1e-7;
C=I*u/(4*pi);
x=linspace(-4*R,4*R,Nx);
y=linspace(-2*R,2*R,Ny);
t0=linspace(0,2*pi,N+1);
t1=t0(1:N);
y1=R*cos(t1);
z1=R*sin(t1);
t2=t0(2:N+1);
y2=R*cos(t2);
z2=R*sin(t2);
dlx=0;dly=y2-y1;dlz=z2-z1;
xc=0;yc=(y2+y1)/2;zc=(z2+z1)/2;
for i=1:Ny
for j=1:Nx
rx=x(j)-xc;ry=y(i)-yc;rz=0-zc;
r3=sqrt(rx.^2+ry.^2+rz.^2).^3;
dlXrx=dly.*rz-dlz.*ry;
dlXry=dlz.*rx-dlx.*rz;
Bx(i,j)=sum(C*dlXrx./r3);
By(i,j)=sum(C*dlXry./r3);
end
end
Bax=Bx(:,41:81)+Bx(:,1:41);Bay=By(:,41:81)+By(:,1:41);
mesh(x(41:81),y,Bax);xlabel('x');ylabel('y');axis tight
daspect([1 1 1e-7])