Utilising thin walls in "Boundary Conditions"

James_mCFD · November 18, 2021, 07:53

I've set up my geometry using Design Modeller. I have a solid object which represents my fluid body, and I've created an external thin wall with a thickness of 0 from this object and combined these two objects as one part.

I've meshed this body, named the thin wall as a hot temperature source and named the surface of the fluid body (excluding inlet and outlet), as the cold walls. I can't select the internal sides of the thin wall as when I hide the internal body and try to select the internal sides, it just highlights the external faces.

What I want to do is utilise this thin wall as a constant temperature boundary, and run a transient simulation so the fluid flow in the internal solid object (really confusing nomenclature - that doesn't help

), is heated by this thin wall over time.

My issues are, I can't create a contact between the internals of the thin wall and the edge of the fluid body. I can also not see the thin wall in the "Boundary Conditions" table when setting up the simulation calculation.

I don't understand why there is not just an option to set the wall temperature of the fluid body to a different temperature to the interior of the fluid body at the beginning of the calculation.

I'm using Ansys 18.1, and all guidance would be much appreciated.

Gert-Jan · November 23, 2021, 03:35

What solver do you want to use?

James_mCFD · November 23, 2021, 07:09

I'm using a Laminar solver in fluent (microchannels being simulated, and if Mesh is fine enough it is accurate).

A quick fix that was advised to me by a colleague was to use Standard Initialisation as opposed to Hybrid Initialisation, and set the initial temperatures relative to the inlet.

Gert-Jan · November 23, 2021, 07:24

I would suggest to use CFX which has more tools to handle thin surfaces, interfaces, etc. Might be new for you, but that is my experience.

November 18, 2021, 07:53	Utilising thin walls in "Boundary Conditions"	#1
James_mCFD New Member Join Date: Oct 2021 Posts: 15 Rep Power: 5	I've set up my geometry using Design Modeller. I have a solid object which represents my fluid body, and I've created an external thin wall with a thickness of 0 from this object and combined these two objects as one part. I've meshed this body, named the thin wall as a hot temperature source and named the surface of the fluid body (excluding inlet and outlet), as the cold walls. I can't select the internal sides of the thin wall as when I hide the internal body and try to select the internal sides, it just highlights the external faces. What I want to do is utilise this thin wall as a constant temperature boundary, and run a transient simulation so the fluid flow in the internal solid object (really confusing nomenclature - that doesn't help ), is heated by this thin wall over time. My issues are, I can't create a contact between the internals of the thin wall and the edge of the fluid body. I can also not see the thin wall in the "Boundary Conditions" table when setting up the simulation calculation. I don't understand why there is not just an option to set the wall temperature of the fluid body to a different temperature to the interior of the fluid body at the beginning of the calculation. I'm using Ansys 18.1, and all guidance would be much appreciated.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Thin Walls using blockMesh	varun	OpenFOAM Running, Solving & CFD	6	December 8, 2020 14:18
Distance between walls with thin wall/shell conduction	mir9283	FLUENT	0	May 16, 2018 04:49
[Commercial meshers] Thin Walls Conversion from Fluent Mesh	Isaac	OpenFOAM Meshing & Mesh Conversion	1	March 4, 2016 13:08
shell conduction @ thin walls	Jiri Beran	FLUENT	0	May 18, 2008 15:08
Thin Walls in CFX5	Dave Hargreaves	Main CFD Forum	1	April 14, 1999 13:08

November 23, 2021, 03:35		#2
Gert-Jan Senior Member Gert-Jan Join Date: Oct 2012 Location: Europe Posts: 1,928 Rep Power: 28	What solver do you want to use?

November 23, 2021, 07:09		#3
James_mCFD New Member Join Date: Oct 2021 Posts: 15 Rep Power: 5	I'm using a Laminar solver in fluent (microchannels being simulated, and if Mesh is fine enough it is accurate). A quick fix that was advised to me by a colleague was to use Standard Initialisation as opposed to Hybrid Initialisation, and set the initial temperatures relative to the inlet.

November 23, 2021, 07:24		#4
Gert-Jan Senior Member Gert-Jan Join Date: Oct 2012 Location: Europe Posts: 1,928 Rep Power: 28	I would suggest to use CFX which has more tools to handle thin surfaces, interfaces, etc. Might be new for you, but that is my experience.