A spatially uniform source changes only the zero Fourier mode. Its exact integrated increment over a time step beginning at isThe unnormalised two-dimensional discrete Fourier transform stores a constant field as in element This replacement uses the original variable names and MATLAB indexing. The uniform forcing of a periodic heat equation is integrated exactly in time here. No source multiplier is applied to the other modes, and the zero-mode homogeneous multiplier equals one. Adding only
(1,1).[ref]fft2 documentation by MathWorks. The forward defining sum has no normalization; the linked inverse definition includes the factor .
Keep the existing homogeneous exponential multiplication and add this source increment to that element:for i = 1:nt
t = (i-1)*dt;
u_hat = u_hat .* exp(-alpha*K2*dt);
dq = exp(-t/10) - exp(-(t+dt)/10);
u_hat(1,1) = u_hat(1,1) + nx*ny*dq;
enddq to the unnormalised coefficient would underestimate the physical temperature increment by the factor . Articles by others on the same topic
There are currently no matching articles.