×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Smaller dt Hint Message

Smaller dt Hint Message

Smaller dt Hint Message

(OP)
We're trying to replicate the work done in an older version of HydroCAD using version 9.00.  We are getting message 49 "Hint: Tc<2dt may require smaller dt" for one of our subcatchments.  The Tc is 5.8 minutes.

Our dt was set at 0.50, which we reduced to 0.10, but the message remains.

What do we need to change to satisfy the program and get rid of this message?  Or is this something that should not concern us?

RE: Smaller dt Hint Message

Usually, if the dt is 1/2 of the smallest Tc or less, the error should not come up.  There is a possibility that your minimum Tc is set greater than 5.8 minutes.  You can change this in Settings -> Calculation -> Advanced, but this is usually a different error message.

RE: Smaller dt Hint Message

The default dt of 0.05 hours is suitable whenever the Tc is 0.1 hours (6 minutes) or greater.  For a smaller Tc you will get hint 49, suggesting a smaller dt.  (Be sure to click the message for full details!)

For your Tc of 5.8 minutes, reducing the dt to 0.04 hours will eliminate the message.

Note: The "Minimum Tc" setting is used to arbitrarily raise any Tc that falls below the specified threshold.  This feature is intended for use ONLY when a minimum Tc is prescribed by local regulations.  Otherwise the actual Tc value should be used.

For further information please see www.hydrocad.net/tc.htm
 

Peter Smart
HydroCAD Software
www.hydrocad.net
 

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources