hi! its my 1st time mailin in this forum, we are doin analysis of a piping system of a compressor of 960 rpm to b installed. the pulsation study of the compressor has been done by te munufacturer,but we r designing the piping system ,so wat r inputs required 2 inputted in the harmonic analysis ,also plz tell me the is the statring freq is natural frequncy & wat should be the ending frequency.
compressor manufacturer has mentioned that the frequency in the equipments n the piping near the should b 48 hz miinimum.wat dose that mean.(48 is multiple of 960/60 by 3 times,which may be the # of N)please do help me in this .b/c im using caresar n the bynamic anlysi 4 the 1st time, n we dont have many expert ppl here in pakistan

The frrequency you are referring to 48hz appears to be very high.Howeever if this the frequency you have to achieve innthe system you may have to model the support stiffness also and run the modal analysis for an accurate behaviour.Minimize gaps,friction.Also have a look at CAESAR II technical references in help menu.

However if the line is connected to a reciproc compressor,the design of piping system is final after a acoustic/analog study normally done by the comp vendor.

Wajahat, if your instructions are to design above a certain frequency, then I think you should be using the Modal analysis to examine the freqencies and associated mode shapes.
Harmonic analysis is not the tool to use for your stated problem, as it is normally used to evaluate existing vibration problems. With harmonic analysis, you require three inputs: excitation frequency, magnitude and application point. The magnitude can either be a displacement or force. The combination of them, applied at a given point in the system will allow CAESAR to predict the system response. Using CAESAR, it is impossible to predict what your system response will be prior to construction. Harmonic response curves are very narrow, CAESAR cannot calculate the EXACT natural frequency, the system will not be constructed exactly the way you inputted it in CAESAR, and you don't know exactly what the forcing function will be.
I hope this helps.