FINITE DIFFERENCE
In numerical analysis, two different approaches are commonly used:
The finite difference and the finite element methods. In heat transfer
problems, the finite difference method is used more often and will be
discussed here. The finite difference method involves:
Establish nodal networks
Derive finite difference approximations for the governing
equation at both interior and exterior nodal points
Develop a system of simultaneous algebraic nodal
equations
Solve the system of equations using numerical schemes
The Nodal Networks
Finite Difference Approximation
Finite Difference Approximation cont.
Finite Difference Approximation cont.
A System of Algebraic Equations
Matrix Form
Numerical Solutions
Iteration
Example
Example (cont.)
Example (cont.)
Summary of nodal finite-difference
relations for various configurations:
Case 1 Interior Node
0
4T
T
T
T
T n
m,
n
1,
m
n
1,
m
1
n
m,
1
n
m, 



 



Case 2
Node at an internal corner with convection
1, , 1 1, , 1 ,
2( ) ( ) 2 2(3 ) 0
m n m n m n m n m n
h x h x
T T T T T T
k k
    
 
      
Case 3
Node at a plane surface with convection
1, , 1 , 1 ,
(2 ) 2 2( 2) 0
m n m n m n m n
h x h x
T T T T T
k k
   
 
     
Case 4
Node at an external corner with convection
, 1 1, ,
( ) 2 2( 1) 0
m n m n m n
h x h x
T T T T
k k
  
 
    
Case 5
Node at a plane surface with uniform heat flux
0
4
'
'
2
)
2
( ,
1
,
1
,
,
1 




 

 n
m
n
m
n
m
n
m T
k
x
q
T
T
T

FINITE DIFFERENCE using numerical method.ppt

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    FINITE DIFFERENCE In numericalanalysis, two different approaches are commonly used: The finite difference and the finite element methods. In heat transfer problems, the finite difference method is used more often and will be discussed here. The finite difference method involves: Establish nodal networks Derive finite difference approximations for the governing equation at both interior and exterior nodal points Develop a system of simultaneous algebraic nodal equations Solve the system of equations using numerical schemes
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    A System ofAlgebraic Equations
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    Summary of nodalfinite-difference relations for various configurations: Case 1 Interior Node 0 4T T T T T n m, n 1, m n 1, m 1 n m, 1 n m,         
  • 14.
    Case 2 Node atan internal corner with convection 1, , 1 1, , 1 , 2( ) ( ) 2 2(3 ) 0 m n m n m n m n m n h x h x T T T T T T k k              
  • 15.
    Case 3 Node ata plane surface with convection 1, , 1 , 1 , (2 ) 2 2( 2) 0 m n m n m n m n h x h x T T T T T k k            
  • 16.
    Case 4 Node atan external corner with convection , 1 1, , ( ) 2 2( 1) 0 m n m n m n h x h x T T T T k k          
  • 17.
    Case 5 Node ata plane surface with uniform heat flux 0 4 ' ' 2 ) 2 ( , 1 , 1 , , 1          n m n m n m n m T k x q T T T