[igor_vidic]

Hi everyone, I' am working on my graduating thesis and I really need help. I am modeling heat transfer between fuel rod and primary water in nuclear reactor, i.e. it's basic cell. So geometry is square cylindar devided in four regions. In center there is cylinder whic represents fuel rod. It is devided in three radial zones (fuel, cladding and helium gap between). Also i divided fuel in 12 parts in axial direction (z-axis) because i had to put differtent volume heat sources in each od them. Around the fuel rod flows water, so final geometry has square chilindar shape. I used four different sketches to drwa four regions (water, fuel, gap and cladding). In adition, total geometry is ver long (3.6m) and very thin (only 1.2 cm). I created name selections on the beginning and on the end of the watter region. Furthermore I made input boundary contion as mass-flow input and output as pressure outlet. Other B.C. are set as coupled walls.

My model finnaly converged after about 1500 iterrations and i didn't have any warnings during it, but final results have no any sense. The temperature is everywhere the shame and velocity is almost everywhere 0, even on the input. I tried laminar and turbelent flow (k, epsilon).
I was told that I had to inprove my mash so i put edge sizing and inflation layers but it didn't help. Moreover in this case model didn't converge. What should I do and which mesh method should I use? I need someone who will increas mesh and get real results.
I am working in ANSYS fluent.
I will pay.

[igor_vidic]

[igor_vidic]

[karachun]

Mesh is awful, it is too coarse. Use at least 10 elements per proximity length. If both nodes of fluid element lie on wall then all velocities will be zero.

[steve lee]

Should make more inflation layers.
Cell size is too big..

[MekTek]

Hi,


I can certainly help you on this.



I am experienced in academia as well as in the industry in CFD. If you need step by step guidance, mail me on mekteksolutions@gmail.com or whatsapp on +919940897882



We will get this done.

[EveS]

Hello, Igor!
There are several options for you. If you will need this in the future better to study, I will be happy to provide some useful materials and my advice. If you just need to do this ASAP, please send the geometry to my e-mail eve.s.cfd@gmail.com

[ShivshreeTech]

Hi,

I have experience on similar type of project you can contact me on,

info@shivshreetech.com