DURATION TIME INPUT IN WATER HAMMER ANALYSIS EXAMPLE (APHAM1)

Question

Hi, 
 I went through example about water hammer in AutoPipe, I have question about step 11, input on Load/Dynamic Analysis/, 
 Duration Sec=0.443 sec, from tutorial file I can see, 0.443sec=first period 0.384sec+duration 0.059sec, 
 I also opened previous verson AutoPipe help file, 0.462sec=first period 0.392+duration 0.07sec had been input, 
 I am wondering where the number 0.384 or 0.392 sec come from and why the same problem has two different numbers of first period from different version of software? 
 and How duration time 0.007 or 0.059 had been calculated? 
 there are also different in Water Hammer Step 11 Notes 
 Thanks 
 Limin

zhang.limin@msn.com · Accepted Answer

I got answers, 0.392/0.384 are come from frequency report first line, first model frequency number, 
 0.007/0.059 are from WI file

Jessica Alegre · Answer

Hello Limin, 
 
Yes your response is correct. 
 
.384 seconds comes from the period of the first mode in the Frequency Report. 
 
0.59 seconds comes from the .THL file that is created from loading the fluid transient events. It should be the time after all of the transients in the even are complete. In this example, this is found in W2.THL. 
 
Thanks, 
Jessica Alegre 
Mechanical Application Engineer

Mike Dattilio · Answer

Hello All, 
 See WIKI page here for more questions and answers on this topic. 
 Regards, 
 Mike Dattilio 
 Bentley Product Advantage Group Analyst 
 AutoPIPE Product Line Bentley Systems, Inc. 
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