Spring2008:Report:Smith

From GeoMod

Contents 1 Graphs 2 Stability Criteria 3 Steady State: Explicit Solution 4 Implicit vs. Explicit 5 excell file

Graphs

Both the explicit and implicit are the same at the 1000 time step. The models begin to differ at the 20000 level because the explicit model reaches numerical instability.

Stability Criteria

Within the explicit model S cannot has to remain < 0.5 for the model to remain numerically stable. The implicit model never loses stability.

Steady State: Explicit Solution

A time step of 5000 produces a S=0.5

Implicit vs. Explicit

Implicit: advantage:Stable no matter how large the S. disadvantage:When programming you have program the itterative solver.

Explicit: advantage:easier to program disadvantage:If S>.5 model loses stability

excell file

Implicit_explicit_temp.xls