How to correctly simulate the nozzle at the top of the equipment in CAESAR?
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How to correctly simulate the nozzle at the top of the equipment in CAESAR? When simulating nozzles, CAESAR gives an error message at the top nozzle indicating that the nozzle’s center line is aligned with the equipment’s center line; I’m not sure how to handle this situation As I understand it now, there are the following two approaches; I’m not sure if they are reasonable: (1) If it’s not possible to do it correctly, given that the expansion amount of the equipment, which is a pressure vessel at normal pressure, is very small, an opening can be made at the nozzle position to use it as an anchor point for calculations. (2) Is it possible to go directly from the CNode to the top of the container without entering nozzle? I look forward to your advice. Thank you.
Half of the tower top has nozzles defined based on additional displacement, or it is connected to the equipment using cnodes. Either of these two methods works. If you don’t want to include equipment models in the pipeline model, you can calculate the additional displacements manually and define them in the software. If you want to include the equipment in the pipeline model as well, you can use cnodes for connection. Defining the additional displacement directly is slightly more conservative than incorporating a device model, and the resulting forces and moments will also be slightly larger. The nozzles at the top of the tower are all located at the head; it is not recommended to use nozzles in order to take into account the flexibility of the pipes, as the results obtained are not accurate enough.
Reply to 2# llu85: Hello, I would like to ask whether the following steps are required when using a CNode to connect to a device for simulation: (1) Define a vertically upward straight pipe segment at the nozzle location at the top of the device, such as from 100 to 110 (the original nozzle position); (2) Define ANC at the flange of the pipe, with values of 10-20, where 20 corresponds to point ANC and 110 corresponds to point conde. I appreciate your guidance. Thank you
For end-cap nozzles, it’s sufficient to use direct ANC-based simulation. If the NOZZLE simulation is used, PD5500 must be employed; otherwise, WRC297 will display an error message. The results obtained using WRC297 cannot be trusted, so it is recommended to use direct ANC association or PD5500 instead
Regarding the PD5500, what are the differences in usage compared to WRC297?
The question raised by the original poster is also one that has always concerned me, and I hope experts can offer their guidance. I would also like to ask how the additional amount of initial displacement is determined, and what are the quantitative relationships between the displacement amount and the magnitude of the force?
It is recommended to create a device model for simulation, with the top port linked using an anchor. The simulation of the nozzle is only applied to the equipment cylinder; the calculations for the head are inaccurate. I remember that the PD5500 was used on some storage tanks, but in our designs we rarely use the PD5500; instead, we mostly use ANCHOR for such connections. The design isn’t very complicated, and sometimes we opt for a more conservative approach.
For simulating the nozzles at the top of the equipment, use WRC107; WRC297 is only suitable for stress analysis on the cylinder and branch pipes
Pay attention, learn*: I usually first estimate the displacement myself and then enter it manually in the displayment, hehe
Agree with the opinion from the 9th floor! For simulating the nozzles at the top of the equipment, use WRC107; WRC297 is only suitable for stress analysis on the cylinder and branch pipes
This post was last edited by levjod on 2011-1-22 at 15:16. (1) Considering that the expansion amount of the equipment, being a pressure vessel at normal pressure, is very small, an opening is made at the nozzle position to serve as an anchor point for calculations. (2) Do not enter nozzle; go directly from cnode to the top of the container. Either method is acceptable; the second method is recommended, and that’s how we handle it in our projects!