Learning Forum

[Saheed Lawanson]

Quick model description: I have a solar cooker model which is basically

• a hollow cube (representing a wooden box) containing a thin hollow trapezoidal shaped (representing an absorber plate).
• The space between the box and absorber plate is filled with a geometry to represent the insulator.
• Also there's a frame (serves as the lid) which holds two thin rectangular geometries with a little space in between (to represent a double glazing).
• Finally the space between the glazing and the space in the absorber plate is filled with a geometry (to represent air).

Here is a link to the STEP file of my geometry: https://drive.google.com/file/d/1SwaqV8MOfjSf9Q5aW1YB3jIpUWpRqvOs/view?usp=share_link

Problem: I get this error message: Quality failure limits are exceeded on some solid bodies. See the Troubleshooting Section of the Meshing User Guide to improve quality whenever i try to generate a mesh on my model. I'm not sure what's causing this issue, but i think its as a result of my very thin absorber plate and the thin layer air in between the double glazing. Please how can i get past this without having to use an extremely small mesh that'll run forever in fluent, plus i can't even exceed 512000 elements with my student license

Questions i think i might get
1. What version of ANSYS are you using? ANSYS 2023 R1 Student

[Keyur Kanade]

First check the locations of the bad elements. Please see following video for the same. 

 

https://www.youtube.com/watch?v=ZDADSSN8hOs

 

 

Once you have locations, please check if you can improve mesh using different mesh sizing. Please see following video. 

 

https://www.youtube.com/watch?v=w4q6q8nKF3U

 

 

You can see more information about sizing at following link. 

https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v221/en/wb_msh/msh_Use_Adv_SF.html?q=sizing

 

 

If this does not help, please go to geometry and modify or simplify geometry at those locations in SpaceClaim. 

Regards,

Keyur

How to access Ansys Online Help Document

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Fluids Engineering Courses | Ansys Innovation Courses

 

[Saheed Lawanson]

 

 

Hey thanks, i was able to simplify the model and it made my meshing easier. I am using shell conduction to model the conduction along the three layers of materials: aluminium (absorber plate), glass wool (insulation), wood (outer casing), but i have a question:

What i can picture from the info i got in the documentation is: Applying shell conduction to a surface basically extrudes a new layer from that surface and applies the selected material then simulates conduction through that extruded surface. Let’s say my geometry is a cube that’s open on the top (2D illustration below):

             |                               |
             |                               |
             |                               |
             |__________________ |

If i apply shell conduction to all outer sides of the cube including the bottom (a, b and c), does shell conduction just do the extrusion for each face and then simulate conduction or does it account for the edges also (d, e)? 

       |         |                               |        |
       |         |                               |        |
       |   a    |                               |  b    |
       | ___  |_______________ ___| ____ |
       |   d    |               c              |  e    |      
       | ___  |__________________ | ____ |

 

 

[Rob]

There's a section in the documentation regarding how layers link. The extrusion (good way to explain) is virtual so the sections d & e don't really exist. But layers will link under some circumstances.