How can I set two diff. heat transf.coeff. on either sides of a virtually thickened wall in wall BC?
November 10, 2019 at 6:47 pmsoumitra2102Subscriber
How can I set two different heat transfer coefficients on either sides of a wall boundary face if I use thickness option in wall boundary condition definition?
I have single fluid domain (pipe) surrounded a another fluid domain separated by a solid domain. I don't want to model the solid domain due to its very thin thickness and surrounding fluid domain due to its constant temperature.
Can I provide separate momentum and thermal properties on either side of the separating domain without actually modelling (/meshing) it?
November 11, 2019 at 6:05 amDrAmineAnsys EmployeeIf it is a internal solid located between two fluids you can use shell conduction assign thickness and leave thermal tab as coupled. Convection boundary condition applies rather if external boundary
November 11, 2019 at 6:07 pmsoumitra2102Subscriber
Did you mean 'System Coupling'?
If so, I do not see Shell Conduction option there.
Also, is it possible to to apply two different heat transfer coefficient on either side of the face selected for wall boundary condition with (virtual) thickness applied?
Or maybe, is modeling/meshing a thick-solid-domain mesh for wall thickness is mandatory to do so?
P.S. Although I have three domains (fluid1-solid-fluid2) in real life, I have defined only fluid1 domain in the simulation setup. Fluid2 domain is just for a constant temperature source. And the solid domain is in-between the two domains for conjugate heat transfer.
November 12, 2019 at 4:50 pmRobAnsys Employee
Heat transfer from the fluid to a wall is calculated by Fluent. You only set a HTC for the outside of a domain where we don't have cells.
November 12, 2019 at 6:27 pmsoumitra2102Subscriber
Okay, got it!
So you mean, if I want to assign two different HTCs on either side, I will have to model the wall thickness, right?
November 12, 2019 at 8:08 pmDrAmineAnsys EmployeeAgain if it is internal wall everything is done by Fluent. You keep the default option to coupled (You can modify that and overwrite what Fluent is doing but you need some expert knowledge hete). (Not talking about system coupling). If the wall has no cells at one side you might that kind of boundary.
November 13, 2019 at 6:02 pmsoumitra2102Subscriber
That means I have to create mesh on other side (even though it has constant (temperature and pressure) conditions) if I want to see the Coupling option.
By the way, I am interested in the manual HTC assigning option because I do have a correlation which I want to test.
November 14, 2019 at 10:16 amRobAnsys Employee
Coupled means we have cells on both sides: heat can pass through the wall. If you want to alter the Fluent fluid-wall heat transfer models you'll need to write a wall function UDF: I don't recommend it given the questions you're asking and won't be helping on here beyond suggesting you attend training.
In Fluent we use the wall function models (there are several) to calculate the heat transfer from the fluid to the wall. This flux can then be used in equations to determine an HTC: in Fluent we have a few different definitions. Note the HTC is a derived value used to compare things in engineering, where flux and temperature may vary between cases.
- You must be logged in to reply to this topic.
Boost Ansys Fluent Simulations with AWS
Computational Fluid Dynamics (CFD) helps engineers design products in which the flow of fluid components is a significant challenge. These different use cases often require large complex models to solve on a traditional workstation. Click here to join this event to learn how to leverage Ansys Fluids on the cloud, thanks to Ansys Gateway powered by AWS.
Earth Rescue – An Ansys Online Series
The climate crisis is here. But so is the human ingenuity to fight it. Earth Rescue reveals what visionary companies are doing today to engineer radical new ideas in the fight against climate change. Click here to watch the first episode.
Subscribe to the Ansys Blog to get great new content about the power of simulation delivered right to your email on a weekly basis. With content from Ansys experts, partners and customers you will learn about product development advances, thought leadership and trends and tips to better use Ansys tools. Sign up here.
- Suppress Fluent to open with GUI while performing in journal file
- Floating point exception in Fluent
- What are the differences between CFX and Fluent?
- Heat transfer coefficient
- Getting graph and tabular data from result in workbench mechanical
- The solver failed with a non-zero exit code of : 2
- Difference between K-epsilon and K-omega Turbulence Model
- Time Step Size and Courant Number
- Mesh Interfaces in ANSYS FLUENT
- error: Received signal SIGSEGV
© 2023 Copyright ANSYS, Inc. All rights reserved.