2
$\begingroup$

I have a 2-dimensional system with behavior governed by Langevin dynamics in which disks (circles) move through a fluid. In the Langevin equation, there is a velocity-dependent term that accounts for a frictional force. What expression would give me the frictional force acting on a disk?

I have only seen solutions of Stokes law for spheres; what is the two-dimensional analog?

$\endgroup$
-1
$\begingroup$

I suggest using the general drag relation: $$F_d=0.5C_d\rho_lv^2D$$ where $F_d$ is the drag force per unit length, $D$ is the diameter of the cylinder and $v$ is the relative velocity norm between fluid and cylinder. The drag coefficient depends on the regime, for $Re<0.1$, $C_d\propto Re^-1$, for $Re>>1$, $C_d\approx1$

| cite | improve this answer | |
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.