One piping system consisting of a puncured run to be analyzed and that pipe pipe is at elevated temp. The holes will be acting like an orifice and the flow through that is in choked condition. How does CAESAR support to model that run?

Krishanu,

CAESAR II Uses infinitely thin " stick elements" for analysis, so you do not get a 3D effect of the hole. You can consider a stress intensification factor ( say two)to simulate the stress concentration factor due to the hole. You can consider a "PSV type situation " by giving a force input at that point to simulate the effect of flow through the hole with a Dynamic load factor.In my opinion that is the only way to simulate the effect.

By the way can you elaborate a little bit ? How can a system be allowed to work with a hole ? Are the holes drilled for some specific purpose ?Also based on which studies you got the information that the flow through the hole will be choked?

Regards

Anindya Bhattacharya

That system is serving the purpose of Bleed Heating. It takes out bleed form compressor and heat the inlet air of the same. Temp. variation at compressor bellmouth affects the performance so that mixing must be uniform and thats why it is designed for choked flow.

One of the first lessons I was taught when I got into this business:

"The hole goes on the inside of the pipe"