Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.
2d line integration (Circle to Sphere)
Posted Apr 14, 2016, 4:50 p.m. EDT 2 Replies
Please login with a confirmed email address before reporting spam
Hi everyone,
I'm trying to solve a creeping flow problem in 2d, using circles. I have a sphere moving in fluid and I want to integrate the shear stress in the x direction, to obtain the drag on a sphere of this size radius. I am not getting the correct answer by integrating it one time as a line integral, so I was thinking I will need to somehow integrate again to obtain the shear stress on the entire surface of a sphere.
How can I do this, using the 2d module? The 3d module is giving me too much trouble meshing, so 2d will simplify things substantially.
Thank you,
Adam
I'm trying to solve a creeping flow problem in 2d, using circles. I have a sphere moving in fluid and I want to integrate the shear stress in the x direction, to obtain the drag on a sphere of this size radius. I am not getting the correct answer by integrating it one time as a line integral, so I was thinking I will need to somehow integrate again to obtain the shear stress on the entire surface of a sphere.
How can I do this, using the 2d module? The 3d module is giving me too much trouble meshing, so 2d will simplify things substantially.
Thank you,
Adam
2 Replies Last Post Jun 3, 2016, 1:58 p.m. EDT
Please login with a confirmed email address before reporting spam
Posted:
9 years ago
Hello Adam,
Your model should be 2D axisymmetric (not 2D, otherwise you're modeling a cylinder, not a sphere), and the geometry should involve a rectangle minus a half disc. Assuming you've set it up that way, you can compute the line integral on the perimeter of the half-disc of the z stress, making sure to check the "compute surface integral" checkbox so the "2*pi*r" factor is factored in the integration.
Best regards,
Jeff
Your model should be 2D axisymmetric (not 2D, otherwise you're modeling a cylinder, not a sphere), and the geometry should involve a rectangle minus a half disc. Assuming you've set it up that way, you can compute the line integral on the perimeter of the half-disc of the z stress, making sure to check the "compute surface integral" checkbox so the "2*pi*r" factor is factored in the integration.
Best regards,
Jeff
Please login with a confirmed email address before reporting spam
Posted:
9 years ago
Thank you Jeff, I ended up resulting to this. Appreciate the help!
Adam
Adam