5.4.1 Neumann Type

For Neumann boundary conditions one gets

$$\nu_{i} \nu_{i} \nu_{i,C}$$ = 0 (5.16)

$$\sum_{i}^{} \nu_{i}$$ f_FC = = 0 (5.17)

with i running over all segment grid points. $\mathbb {T}$_B reads (for two example grid points i₁ and i₂)

tx, y	$\nu_{i_{1}}^{}$	$\nu_{i_{2}}^{}$	FC
$\nu_{i_{1}}^{}$	1
$\nu_{i_{2}}^{}$		1
FC	1	1

Since there is no segment model for F_C the respective column is arbitrary.