Welcome to CivilGEO Knowledge Base
Welcome to CivilGEO Knowledge Base
Welcome to CivilGEO Knowledge Base
Welcome to CivilGEO Knowledge Base
In GeoHECRAS, the Advanced Time Step Control panel of the Unsteady Flow Computational Options dialog box allows the user to control both fixed and variable computational time steps in unsteady flow computations.
The above panel provides three different options to control for selecting and controlling the computational time step:
Note that variable time step options can improve model stability and reduce computational time. However, not all models will be faster with the use of the variable time step.
The following sections describe how to interact with the Advanced Time Step Control panel of the Unsteady Flow Computational Options dialog box.
This option allows the user to define a fixed computational time step. The value for the fixed computational interval should be chosen with care and consideration as to how it will affect the simulation. Refer to this article in our knowledge base to learn how time step values can affect the stability of the model.
This option allows the user to use the Courant number method for the variable time step. To use this method, select the Allow Variable Time Step Using Courant option.
The following entries are provided for the user:
This option allows the user to set the variable time step based on a user-defined table of dates and times versus a time step divisor.
The user can select the Allow Variable Time Step Using Time Series Divisors option to enter date/time values versus time step divisors. The first date/time in the table must be equal to the starting date/time of the simulation period. In the table, the user must enter a base time step equal to the maximum time step desired during the run. Then in the Divisor column, an integer value should be defined using the spin control to divide that time step by the current date/time in the table. Once a time step is set for a date/time, the Unsteady Flow Analysis computation will use that time step until the user sets a new one.
This method requires much more knowledge about the events being modeled, the system being routed through, as well as knowledge of velocities, cross section spacing, and 2D cell sizes. However, this method can be a powerful tool for decreasing model run times and improving accuracy if done correctly.
1-800-301-02-955
608-729-5100
(US and Canada)
[email protected]
+1 608-729-5100
CivilGEO India
Graphix Tower, A-13 A
3rd Floor, Sector 62
Noida, Uttar Pradesh 201309
IndiaTel:
1-800-301-02-955 or
+91 022-3831-8601
CivilGEO United States
8383 Greenway Blvd
6th Floor
Middleton, WI 53562
USATel:
608-729-5100 or
800-488-4110
Copyright © CivilGEO, Inc. All rights reserved. The CivilGEO logo, “GeoHECHMS”, “GeoHECRAS”, and “Ready To Engineer” are registered trademarks of CivilGEO,
Inc. All other brands, company names, product names or trademarks belong to their respective holders.
We use cookies to give you the best online experience. By agreeing you accept the use of cookies in accordance with our cookie policy.
When you visit any web site, it may store or retrieve information on your browser, mostly in the form of cookies. Control your personal Cookie Services here.
The ZoomInfo WebSights snippet drops three cookies to track Unique Visits:
1. _pxhd - Related to the Perimeter X security layer (Perimeter X isused to prevent bot attacks).
2. _cfduid - Related to the CloudFlare security layer (CloudFlare is the Network Security protocol that ZoomInfo uses to orchestrate the rate limiting rules).
3. visitorId - This is how WebSights identifies recurring visitors