How to apply angle of attack on a 2D axisymmetric body?

funnier · January 29, 2024, 13:04

I’m doing cfd simulation of rocket on Ansys cfx, the geometry of rocket is 2D axisymmetric. How can I apply angle of attack on rocket?

ghorrocks · January 29, 2024, 17:12

I presume the rocket is long and cylindrical, possibly with a conical nose. And by angle of attack you mean the rocket is not travelling in the direction of its axis, it is slightly off.

In this case the simulation is not a 2D axisymmetric model any more. You can going to have to use the full 3D geometry. You may be able to use a symmetry plane depending on what wake structures you expect to see (some wake structures are non-symmetric, so you would need a full 3D model with no symmetry plane to capture these).

funnier · January 29, 2024, 18:11

I uploaded picture of the rocket. Can you please look at it?

ghorrocks · January 29, 2024, 18:29

As I said, you are going to have to generate a full 3D model of this. So take your 2D slice and rotate it around to generate a 3D body. Then do a rotation on the body it to generate the angle of attack you want.

You will then have to remesh and run the simulation again as a full3D model. It will take a lot longer to run, of course, as the mesh will be much larger.

January 29, 2024, 13:04	How to apply angle of attack on a 2D axisymmetric body?	#1
funnier New Member Join Date: May 2022 Posts: 6 Rep Power: 4	I’m doing cfd simulation of rocket on Ansys cfx, the geometry of rocket is 2D axisymmetric. How can I apply angle of attack on rocket? Last edited by funnier; January 29, 2024 at 18:10.

January 29, 2024, 17:12		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	I presume the rocket is long and cylindrical, possibly with a conical nose. And by angle of attack you mean the rocket is not travelling in the direction of its axis, it is slightly off. In this case the simulation is not a 2D axisymmetric model any more. You can going to have to use the full 3D geometry. You may be able to use a symmetry plane depending on what wake structures you expect to see (some wake structures are non-symmetric, so you would need a full 3D model with no symmetry plane to capture these). Opaque likes this. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

January 29, 2024, 18:29		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	As I said, you are going to have to generate a full 3D model of this. So take your 2D slice and rotate it around to generate a 3D body. Then do a rotation on the body it to generate the angle of attack you want. You will then have to remesh and run the simulation again as a full3D model. It will take a lot longer to run, of course, as the mesh will be much larger. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Calculating Oscillating Aerofoil Angle of Attack	MechEng86	FLUENT	1	August 20, 2019 09:19
Angle of Attack simulations	redordead	FLUENT	2	June 15, 2016 04:50
how to plot attack angle along with impeller span direction at leading edge	wildli	FLUENT	0	August 31, 2010 15:47
convegence problem with high angle of attack	littlelz	CFX	2	October 28, 2009 07:07
Proper output of angle of attack in CFX post	Kevin	CFX	3	October 18, 2006 13:18

January 29, 2024, 18:11		#3
funnier New Member Join Date: May 2022 Posts: 6 Rep Power: 4	I uploaded picture of the rocket. Can you please look at it?