[ICEM] Meshing according to the flow problem - External Aerodynamics.

shereez234 · March 5, 2015, 08:37

Dear Every one!

I am working on a Thesis regarding Ground effect on external aerodynamics of a generic Aircraft model. I have some doubts regarding this. I am an experienced user of ICEM to some extent ! but I have problems in understanding the best concepts! So if any one can help me out I will be grateful. Here are some questions in my mind?

1) What type of mesh is better for External aerodynamics? Blocked structured mesh or Unstructured tetra delaunay or AF mesh with resolve boundary using prism layers? Does the type of the mesh change the results a lot? Or is the effect in results negligible?

2) When you have Density regions such as wake behind the wing how far do you extend it? 2 times the length of Aircraft? What is the standard way?

3) How many cells are in a fine or a coarse mesh for an Aircraft? Because I saw in a NASA Document that 12 million elements of an unstructured mesh is still Coarse!

4) What factors can be considered to minimize the number of cells in a mesh but still capture the important parts in a refined manner?

5) I have problems when it comes to the curvature of the wings using octree meshing? Which factors can be set to enable the mesh to capture the surface curvature? Is it the curvature/proximity refinement? Edge criterion?

Feel free to post any opinions. Regards and thank you in advance

shereez234 · March 5, 2015, 15:49

Any answers would be appreciated. Please help

Viki24 · August 17, 2023, 15:57

Hello Shereez, I am late to the question. But I hope you would have an answer to those questions you had previously.
I am performing an external aero analysis using Fluent and ICEM for meshing, and I would like to know those answers if you know them.
I will be performing an unstr viscous mesh, but the problem is the geometry is complex and has a lot of faces.
Your info would be of great help.
Thanks!

March 5, 2015, 08:37	Meshing according to the flow problem - External Aerodynamics.	#1
shereez234 Senior Member M Sereez Join Date: Jan 2014 Location: England Posts: 352 Blog Entries: 1 Rep Power: 13	Dear Every one! I am working on a Thesis regarding Ground effect on external aerodynamics of a generic Aircraft model. I have some doubts regarding this. I am an experienced user of ICEM to some extent ! but I have problems in understanding the best concepts! So if any one can help me out I will be grateful. Here are some questions in my mind? 1) What type of mesh is better for External aerodynamics? Blocked structured mesh or Unstructured tetra delaunay or AF mesh with resolve boundary using prism layers? Does the type of the mesh change the results a lot? Or is the effect in results negligible? 2) When you have Density regions such as wake behind the wing how far do you extend it? 2 times the length of Aircraft? What is the standard way? 3) How many cells are in a fine or a coarse mesh for an Aircraft? Because I saw in a NASA Document that 12 million elements of an unstructured mesh is still Coarse! 4) What factors can be considered to minimize the number of cells in a mesh but still capture the important parts in a refined manner? 5) I have problems when it comes to the curvature of the wings using octree meshing? Which factors can be set to enable the mesh to capture the surface curvature? Is it the curvature/proximity refinement? Edge criterion? Feel free to post any opinions. Regards and thank you in advance

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Boundary condition problem for open channel flow	Andy	CFX	9	June 11, 2016 07:20
[ICEM] Meshing External Flow Tanker	rzhang	ANSYS Meshing & Geometry	2	February 2, 2014 20:50
Low Mixing time Problem	Mavier	CFX	5	April 29, 2013 00:00
Problem in external flow at ROV	projecthiago	FLUENT	0	April 15, 2013 07:43
[ICEM] Multizone meshing Problem for External Flow Meshing	Hybrid	ANSYS Meshing & Geometry	9	March 29, 2013 09:24

March 5, 2015, 15:49		#2
shereez234 Senior Member M Sereez Join Date: Jan 2014 Location: England Posts: 352 Blog Entries: 1 Rep Power: 13	Any answers would be appreciated. Please help

August 17, 2023, 15:57		#3
Viki24 New Member Vikram Join Date: Aug 2023 Posts: 2 Rep Power: 0	Hello Shereez, I am late to the question. But I hope you would have an answer to those questions you had previously. I am performing an external aero analysis using Fluent and ICEM for meshing, and I would like to know those answers if you know them. I will be performing an unstr viscous mesh, but the problem is the geometry is complex and has a lot of faces. Your info would be of great help. Thanks!