CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Wiki > TVD scheme

TVD scheme

From CFD-Wiki

(Difference between revisions)
Jump to: navigation, search
Line 3: Line 3:
:<math>
:<math>
TV(u^{n+1}) \le TV(u^n)
TV(u^{n+1}) \le TV(u^n)
 +
</math>
 +
 +
The total variation of a grid function is defined as
 +
 +
:<math>
 +
TV(u) = \sum_j | u_{j+1} - u_j|
</math>
</math>

Revision as of 04:05, 30 September 2005

A scheme is said to be TVD or Total Variation Diminishing if it does not increase the total variation of the solution, i.e.,


TV(u^{n+1}) \le TV(u^n)

The total variation of a grid function is defined as


TV(u) = \sum_j | u_{j+1} - u_j|

Note that a TVD scheme may not satisfy the entropy condition and hence can give incorrect solution. We have the following relationship between monotone, TVD and monotonicity preserving schemes,

Monotone scheme \Longrightarrow TVD scheme \Longrightarrow Monotonicity preserving scheme

TVD condition: Incremental form

TVD condition: Viscosity form

My wiki