--- Welcome to the official ADCIRCWiki site! The site is currently under construction, with limited information. ---
For general information, see the ADCIRC site, ADCIRC FAQ, or the ADCIRC Wikipedia page. For model documentation not yet available on the wiki, see the ADCIRC site. New content is being continuously added to the ADCIRCWiki, and material from the main ADCIRC site will be gradually transitioned over to the wiki.

Ramping

From ADCIRCWiki
Revision as of 22:41, 9 October 2018 by Taylorgasher (talk | contribs) (Initial work on page)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

Ramping is a way by which terms can be steady increased over some period of time in a simulation. This is most often done for model forcing terms, principally in order to avoid applying a shock to the model.

Conceptual Justification

To understand why ramping of forcing terms is needed, consider tides. Starting a model with the water surface and velocity as zero everywhere, but with full tidal forcing, is analogous to having a planet at rest, then instantly putting a moon and sun in place, in motion with each other. This large, instantaneous change in conditions (forcing) is what creates the shock, which tends to result in spurious waves being formed. Ideally, one would initialize a tidal simulation with the water surface and velocity at all points matching what it should be at the point in time the model is initiated, given the phase of the tides, however this is not generally achievable. Gradually scaling up forcing terms helps avoid this problem.

Ramping Parameters

NRAMP controls whether ramping is enabled, as well as how many ramping terms there are. This is to permit users to apply different ramping times for different forcing terms. The various DRAMP* terms...