WRC 297 Nozzle Flexability

Hello All,

While attempting to model a flexible nozzle using WRC 297 (following the guidelines set forth in the CAESAR II Application Guide "Flexible Nozzle - WRC Bulletin 297") I noticed that after running the Error Checker the WRC 297 Nozzle Calculations Caesar II reported an Axial Translational Stiffness (lb/in.) of approximately 10E12 which is the default rigid stiffness value. I'm trying to understand why the software is defaulting to this value?
Furthermore, I noticed that Caesar II software provided a note stating that "The following combinations produce rigid axial junctions: j>1 .6 &=10 / j>2.5 &=20 / j>4 .0 &=50/ j >6 . 2 &=>100". Yet, the calculated j=2.562 and &=3.878. If anyone can shed some light on this issue it would be greatly appreciated.

Thank you.

The stiffness depends on your actual parameters defining the vessel and nozzle. You may actually have a rigid stiffness in some degrees of freedom, depending on your input.

Richard,

Thank you for your input. Based on your reply we could be seeing the default stiffness value as described in the original posting due to "rigid stiffness in some degrees of freedom". Could you elaborate on some examples for a horizontal vessel on saddle supports?

Thank you.

There are several examples of this type of modeling in the Applications Guide. Can you look at these and let me know if you need more information?