myprog1.m

matlab 电流涡流推导,电磁推理计算方法中的一些重要公式.

% declaration of some common variables 
%assuming a=5,b=12.5,z=1,(unit:cm) f=20kHz,i=1000kA,theta=0
a=5*10;b=12*10;c=20*10;l=3*10;z=1;f=20e3;i=1000e3;theta=0;
%the range of the parameters are h=1--4mm,coil length l=3,disk radius
%c=20cm
h=3;
fr=@(r) a/r;%current distribution function 
maxnum=1e10;%a large number used as inf in matlab
order=1;%bessel function order
rou=a/2;
u=100;%permeability constant
Jm=i/(pi*a^2*l);
Jr=@(r) Jm*fr;
omega=2*pi*f;
d=(r-a)*tan(theta);
%kinetic energy calculation  
m=10;
v=100;
k=1/2*m*v^2;
%a basic function for source potential calculation 
faik=quad(@(r) fr*besselj(order,r)*r*exp(-k*r*tan(theta)),0,maxnum);
%The total source current
G=quad(@(r) fr,a,b);
i=(Jm*omega)/G;
zz=z-a*tan(theta);
Aso=u*G*i/2*quad(@(k) faik*besselj(order,k*rou)*exp(-k*zz),0,maxnum);
%the surface current density at disk , combining field equations,
%real part 
%Js=-sqrt(2)*G*i/2*quad(@(lamda)
%faik*besselj(order,lamda*rou)*exp(-lamda*z),0,maxnum)+j*2*v/omega*quad(lam
%da^2*faik*besselj(lamda*rou)*exp(-lamda*zz)/(1-j*sqrt(2)*delta*lamda));
%substituting and simplify 
Aei=-u*G*i/2*quad(