Hi! I'm doing this code on an external body flow. Basically I need to use the standard 2D Cartesian coordinates (x,y) to compute the flowfield around a moving circular cylinder WITHOUT moving the cartesian grid. The frame is fixed and the cylinder is moving in a fixed prescribed velocity and I'm using the streamfunction-vorticity formulation of the Navier Stokes equation to compute.

Usually if the cylinder is fixed (not moving), we can derive the streamfunction at the cylinder by using the summation of (del operator x vorticity) along the cylinder surface. But for moving cylinder, that is not the case. Does anyone know what equation should I use to derive the cylinder streamfunction for the moving case?

Thank you!

fix your frame of reference on the cylinder

Adrin Gharakhani

What about immersed boundary method?

I'm trying not to fix my frame to the cylinder, in case for my future developments, I will need to oscillate two or more cylinders within the same field.

So basically I'd have a "sub" frame moving with the cylinder but with reference to a stationary cartesian frame.