[qutadah.r]

hello everyone,


I am simulating a 2d flow in a cylindrical tube using python, how will i account for the symmetry along the z axis?


I need a boundary condition, since I am only simulating half the tube, assuming n is my radial grid point, I am simulating from n=1 to Nr.


Currently i only used this symmetry to calculated the derivatives at n=1 using central differencing using 2 grid spacings instead of one and then assuming symmetry of the grid point across the axis.


so for example. dux/dx @ n1 = [ux(n=3) - ux(n=-1)]/(2*dx) and ux(n=-1) = ux(n=1).


So the equation becomes:


n1 = [ux(n=3) - ux(n=1)]/(2*dx)


Is this reasonable?


Please help. Thanks!


Regards,
Qutadah