please tell me , how to perform water hammer & steam hammer anallysis using caepipe & caesar. tell me what are the inputs required for the analysis.

One: You should not ask CAEPIPE question in CAESAR forum.

Secondly , kindly technically develop yourself before you do such analysis. It appears from your questions that you are very new to this field and require to work under an experienced engineer( if you have any such in your organization).Else you will do a GIGO analysis.

Regards

You need time/force on bends in your system (normaly on bends).
With this input can make with Caesar a dyn. analysis.

That's a bit a of a harsh reply don't you think? I pretty confident that you also had to start somewhere.

"That's a bit a of a harsh reply don't you think? I pretty confident that you also had to start somewhere."


Yes we all start somewhere... but humans crawl, then walk, and finally run.

Design and analysis of high energy piping systems is "running" wheras a line at 200 300 F is more "walking" or "crawling".

Dynamic analysis is "running"....

Garbage in Gabage out is a prevalent problem these days when managers think that anybody at all can just run the software.

Usually people such as myself get involved in fixing ill completed work done by individuals trying to run before they can crawl.

As for me, I rely on others (Research Papers, conference papers, experienced colleaugues etc.) for my own questions and quandries...

If someone thinks my reponse was harsh, so be it. I don't sympathize with those who do not want to learn things in a methodical and hard way.If I personally do something like this, I would welcome such harsh words.

It appears from Suresh's questions ( I don't think anybody will disagree with this) , he is very new.Now that is not a problem. The problem is when a new comer does not want to learn the basics and wants to do a complex analysis and thinks that the software is a black box where the input is the model and output is the solution.But more than Suresh I would blame those, who assign these type of analysis to people like him. Their ignorance is a crime.

Regards

Anindya,

Suresh's question is very normal and propriate for this forum. It does not matter he personally is a new user or not.

You should have told him how to start rather than reprimand him as ignorance, crime ... etc. You have moral liabilities for what you have done in this forum.

Anindya,
No body is born a stress engineer. You also must have leant from other people. Suresh has posted a normal question. Even if he is not experienced or doing such a analysis in his organization , he has all the right to be interested in learning this. It is always good to be interested in learning and know a little bit before you actually start some work.
If stress analysis always needs to be done by very experienced stress engineers then from where do you think next generation of stress engineers will come ?
Secondly why do people think that they are responsible for some one working faraway? He must be having experienced and good stress engineers in his organization who can guide him and check his work.
Mr. Breen had written a long reply on such issues some time back.You should see that reply.
People should either reply properly to queries or refrain from writing derogatory replies.
I agree with DSL that you have moral liabilities for what you have done.

It is unfortunate that the discussion here turned political.

Anyone really interested in fast transients should enrol in suitable course in local school's continuing education programs. As interest in large size nuclear powerplant is again picking up, such an investment of time and money will not be wasted. Apart from Caesar-II, use of fluid transient software will also be necessary.

'Secondly why do people think that they are responsible for some one working faraway?' - Dear Siv, you don't know that it's their work - for the volumes of inputs the workshare people generate, people like LufSir add value to the same to make them workable and by quality check remain responsible for the work.

regards,

sam

Hi Suresh,

There are many good sources for you to find information that you should study before you pose such a question. I would suggest that you look at ALL the previous issues of the COADE "Mechanical Engineering News" (you can find your way there on this site). The June 1994 issue of that publication has a useful article on "time history analysis" that you really should read. You can ask specific questions about that article here after you are familiar with the concept.

Regards, John.

http://www.coade.com/newsletters/jun94.pdf

'why do people think that they are responsible for some one working faraway?'

Several reasons:

1. We may have to walk through the plant where the faulty analysis was performed, and be unfortunate enough to be there when the debt comes due - i.e. the pipe fails and causes a catastrophe. Mr. Breen's recent trip to Lithuania comes to mind...

2. Even if I personally am not there, such a failure will cause the piping community to review a lot of prior work unnecessarily.

3. Even if I am not personally there, and the "unnecessary" review of the prior work comes at a time where the industry is not otherwise busy, people may be killed or injured. As a professional, I have a responsibility to my community (people and organizations I do business with), and in a larger sense to the world, to avert such events when possible.

4. As a new stress analyst (we all were, once), there is a responsibility to understand and respect ones own limitations. If a new stress analyst doesn't have the faintest idea how to do something, he/she has a responsibility to themselves, and their employer, and to their community, and to the world at large to BACK OFF. Tell your supervisor you don't know how to do something. Better yet, research the resources available to LEARN how to do something, and go to your supvervisor with a two-step statement:

A. I don't know how to do this.

B. For this fee, on this time schedule, you can get me competent lessons that will enable me to LEARN how to do it. Going to a class or seminar with a specific problem in hand can be a terrific experience for both you and the seminar at large.

There are a lot of competent advisors in this forum. Still, one of the issues with questions like this is that the new analyst may not have stated the precise problem he is trying to solve, and the answer given may not be applicable to the problem if it had been properly posed. Trying to drive a nail with an axe is a difficult task at best.

Very rarely can a complex problem be properly defined in 30 words or less. Often 30 pages are required. Acquiring the skill to self-define problems is MANY TIMES more important than learning how to use CAESAR II better. Until you have acquired the experience to do so, it's a good idea to make sure you have a wiser colleague to discuss things with.

Sorry, I don't recommend the use of this forum as a substitute for a wiser head. The lag time between question and answer can be too large, and the quality of the answer is often limited by the quality of the question. I have many times had the responsibility of working with younger engineers. Often, when confronted with all of the evidence (drawings, specs, design basis, etc.) I have realized that the first, and most important, part of the process is to explain to the young engineer exactly what the problem really is. This opportunity is not really available in this venue.

Also, look at the Hammer example in the Applications Guide (From the Caesar II main menu select Help->Online Documentation). This example is a Spectrum analysis instead of a Time History analysis. The Caesar II input file for this example is located in your \Examples directory. Unfortunately, we don't have a Time History example in the manual, something I plan to change whenever I get the time to add one.

To properly excel in one's chosen field, one has to be methodical, open to constructive criticisms , talk to experienced ( real experience and not just by number of years) and learn everything the hard way.

Unfortunately in the part of the world I belong to , because of different reasons ( individual attitude i.e. taking short-cut paths, supervisors who think stress analysis can be done by a data operator, push from prime offices , reluctance to do home work i.e. self study etc.)in most cases these points are missing. People like John Breen, John Luf,Craig B, Sam, in their individual ways try to put people on the right track, in a way help them. I from my side also try to do it in my own way.Unfortunately on many occasions I find my comments are taken in a wrong way, but I simply don't care. The reason being,those who don't follow the four points mentioned in the first paragraph,I don't sympathize with them as they don't deserve any of that. If I personally do it the same way, I welcome such harsh words.That is one of the reason, despite having abundance of talents ( a fact that many of top US university professors are Indian -Americans , definitely shows that there is no shortage of talent in India), most stress engineers I work with or I interview or have interviewed,I find are of abysmally bad quality and don't deserve to work as stress engineers. Not only them , their supervisors are equally bad if not worse.

In fact that is one of the reasons, many of the questions posted from my part of the world are of very childish in nature and answers could have been traced out by the individual if their basics were clear and had they to properly study the code i.e. do a little bit of home work.

What hurts me is that many people don't want to correct these guys rather sympathize with them.

Regards

anindya,

Having worked in the West all my life I would say that India is not alone in unqualified people pretending to do piping flexibilty analysis. 80-90 % of the people here I would not rank as being trustworthy.

So take heart, I see this problem only getting worse as the old farts like Breen fade into the sunset. Historically speaking Pliny the Elder (Roman Scientist) some ~2000 years ago had written complaints about the youth of his era... (Ironically his stuborness led to his own death at the eruption of Mt Vesuvius at Pompeii, his Son Pliny the Younger saved himself bit his father would not listen to his advice).

So what we see today around the world is typical of the human condition past, present, and future....

Take Care....

Anindya,
Quote ur reply: "talk to experienced (real experience and not just by number of years)..." - That is what people are exactly trying to do through this forum. You have admitted that in most of the cases young engineers do not have learned / knowledgeable supervisors to guide them. Asking a question itself is an art just like answering them. Just because people are asking questions in simple language, it does not mean that they have not done any home work. How many people do you think in our country know the science behind the subject topic with adequate practical experience in handling atleast 5-6 real life water hammer problems?

And I totally agree with Mr.Luf that this problem is not only confined to Indian sub-continent but it is universal. In this forum of 2600 odd members going strong for close to 10 years, you were able to list only 4-5 greats (may be there are very very few whom you have left out). With my limited experience in two of the most developed countries in the world I'm pretty sure about this trend.

I totally agree with your words. Nothing can be spoon fed. People should take initiative on their own and I feel this forum is one of the ways of taking the initiative.

From Pliny the elder...

"Among these things, one thing seems certain - that nothing certain exists and that there is nothing more pitiful or more presumptuous than man."

Seems a fitting quote for this thread.....

I believe John Breen was in his 20's around Plinys era.... LOL !!!!

Dear SAMAbdul,

You once worked with me and let me tell you I have never got a co-worker like you who not only is very well conversant on the subject,but also hard working and is hungry to learn something everyday.You ahve asked me many interesting questions which has enhanced my knowledge. However the sad thing is: you are an exception. Do you honestly believe that a person who has visited college need to ask questions like " if my MZ is high what to do?" Even the starting thread is like as if the pesron wants to know how to feed the water hammer data in CAESAR II and get the output. This is what I detest and I am sure that based on your temparament, you also do the same.

I always give your example to the next gen of stress engineers, but unfortunately could not motivate them to be even half of what you are.

Regards

If a teacher/coach tries to motivate a student by comparing him/her with the better ones in the class, the student loses interest in the subject.

Let the person become what he/she wants to be, experiencing joy in every steps of life! Expose a student to the right way & let him/her walk/run!

Young people should understand that confidence in the concerned trade makes the person fearless & its value can't be measured in money! Few years ago I could drive in a busy road in the evening I lost my job - being declared inefficient, just for this reason that I invested my time & effort in self development in my area of work & it is enough for an engineer to earn his bread!

The more we invest in self development, it's better - not for the firm, community, state or the country we belong to, but for the self!

regards,

sam

Hi Suresh,
1.Read Caesar Technical Manual,User manual and Application guide.My Personnel experience is whenever i am having problems in caesar I read manuals, most of times i got answer.

2. Study all mechanical engineering newsletters.

Above points only for beginners.

All the best.

senthil

Senthil,

Good advice, but quite wrong in one respect. Your points are relevant to all of us. Most certainly not just beginners.