Could you give me your advice?
 

I faced a difficulty to compute an equation using numerical method? The equation is as follows. index: c: concentration d: partial differential equation D: diffusion coefficient

dc/dt + v(y,t)dc/dx = D( d^2 c/ dx^2 + d^2 c/dy^2 )

To get c, which method could be recommended?

Thanks in advance for your help.