Understanding how to model a non-isothermal flow through a pipe

  • Thread starter Thread starter JD_PM
  • Start date Start date
  • Tags Tags
    Flow Model Pipe
AI Thread Summary
The discussion focuses on modeling non-isothermal flow through a pipe using conservation laws for mass, momentum, and total energy, along with an equation for the void ratio. The main challenges include determining appropriate equations for modeling the steel component and how to effectively couple the fluid and solid models. Suggestions include utilizing conjugate heat transfer principles and exploring OpenFOAM's chtMultiRegionFoam solver for insights into simulation handling. The need for more literature on this specific coupling issue is highlighted. Overall, the conversation emphasizes the complexity of integrating fluid and solid dynamics in thermal modeling.
JD_PM
Messages
1,125
Reaction score
156
TL;DR Summary
I want to simulate (using OpenFOAM) a flow of water at an initial temperature (say 300 K) passing through a steel pipe at an initial temperature (say 90 K) and write two sets of equations: one that describes the fluid and other the solid. Then these two sets need to be coupled so that eventually both fluid and solid reach the same temperature.

Please note that the aim of this post is to understand the physics behind the problem (i.e. what equations should be studied and how to couple both sets)
For the fluid, I will use three conservation laws for mixture quantities (mass, momentum and total energy) and an additional equation for the void ratio (as explained in the paper "Modeling for non isothermal cavitation using 4-equation models"). If you want I can share the explicit equations.

I have two main issues:

1) What equations should be used to model the steel? I thought of using essentially the same equations that for the fluid but I do not see how to modify them such that it models a solid.2) How to couple both sets? I have been looking into the literature but I did not find a paper addressing a similar issue.

Any help is appreciated, thank you :)
 
Engineering news on Phys.org
I’d rather call this conjugate heat transfer since that’s the kind of problem where you account for heat exchange between the fluid and solid. OpenFOAM has a special solver for that - chtMultiRegionFoam. Check its documentation and maybe even source code. This should give you an insight on how such simulations are handled internally.
 
Thread 'What type of toilet do I have?'
I was enrolled in an online plumbing course at Stratford University. My plumbing textbook lists four types of residential toilets: 1# upflush toilets 2# pressure assisted toilets 3# gravity-fed, rim jet toilets and 4# gravity-fed, siphon-jet toilets. I know my toilet is not an upflush toilet because my toilet is not below the sewage line, and my toilet does not have a grinder and a pump next to it to propel waste upwards. I am about 99% sure that my toilet is not a pressure assisted...
After over 25 years of engineering, designing and analyzing bolted joints, I just learned this little fact. According to ASME B1.2, Gages and Gaging for Unified Inch Screw Threads: "The no-go gage should not pass over more than three complete turns when inserted into the internal thread of the product. " 3 turns seems like way to much. I have some really critical nuts that are of standard geometry (5/8"-11 UNC 3B) and have about 4.5 threads when you account for the chamfers on either...
Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'
Scenario 1 (figure 1) A continuous loop of elastic material is stretched around two metal bars. The top bar is attached to a load cell that reads force. The lower bar can be moved downwards to stretch the elastic material. The lower bar is moved downwards until the two bars are 1190mm apart, stretching the elastic material. The bars are 5mm thick, so the total internal loop length is 1200mm (1190mm + 5mm + 5mm). At this level of stretch, the load cell reads 45N tensile force. Key numbers...
Back
Top