ABSTRACT
The right-hand boundary condition can be written using the right-hand secondorder correct finite difference formula (the third equation in Table 4.2). This is the second-order correct backward difference formula applied at the right boundary:
3 4 2
4 3
4 3
1 3
T T T x
T T T
T T
− + =
=
−
= −
∆ (6.16)
Substituting for Tn+1 results in
T T T
x a T T
T T T T a
− + = −
− + − =
2 4 3
1 3
∆ ( )
∆
∆ ∆
x T T
T a x T a x T
3 2 3
( )−
− +
= −−
(6.17)
So, the last of the n equations is special and accounts for the insulated boundary condition.
