| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a device capable of highly accurately solving a diffusion equation by a Fourier developing method. SOLUTION: On a diffusion quantity f when having a diffusion source s, Fourier transform is performed on a spatial component to f(r,t), and s(r,t) of both members on partial differential coefficient f(r,t)/ t=s(r,t)+Dgrad<2> f(r,t), and an individual spatial frequency component is obtained by the Fourier transform. A differential equation in the form of df(t)/dt=s(t)-cf(t) is transformed, and a difference equation being f(t+Δt)=exp(-cΔt)f(t)+(Δt/2)[exp(-cΔt)s(t)+ s(t+Δt)] is solved by a repetition method.</p> |
