Changeset 7105 for anuga_core/documentation/user_manual/anuga_user_manual.tex

Timestamp:

May 27, 2009, 4:25:47 PM (14 years ago)

Author:

ole

Message:

Optimised compute_fluxes by disabling limitation of momentum perpendicular to the x-axis. Speeds calculated from the x-momentum are still being limited according to the _compute_speeds. All tests pass and the overall improvement is as follows:
For the simple profile compute_fluxes improved from 4.284s to 3.372s and the overall runtime of evolve from 10.909s to 9.941s. This is an overall speedup of more than 8%.

For the okushiri profile example the improvement of compute_fluxes is from 129.432s to 111.703s and the overall runtime was reduced from 312.336s to 293.286s or about 6% improvement. This is probably the more realistic profile.

File:

• anuga_core/documentation/user_manual/anuga_user_manual.tex (modified) (1 diff)

anuga_core/documentation/user_manual/anuga_user_manual.tex

@@ -3347 +3347 @@
 setting $h=H_0$ will scale the predicted speed by a factor of $0.5$:
 \[
-  \left[ \frac{\mu}{h + h_0/h} \right]_{h = H_0} = \frac{\mu}{2 H_0}
+  \left[ \frac{\mu}{h + h_0/h} \right]_{h = H_0} = 
+  \left[ \frac{\mu}{H_0 + H_0^2/H_0} \right] = 
+  \frac{\mu}{2 H_0} = \frac{\mu}{2 h} = \frac{u}{2} 
 \]
 In general, for multiples of the minimal depth $N H_0$ one obtains