Velocity of falling object through fluid flowing upward

[bk PE]

How to calculate the velocity of a object falling due to gravity through a pipe (vertical) where the fluid is flowing in upward direction?

Please ignore the frictional force & just consider
F net = F (gravity) - F (drag) - F (force the fluid exerting on the object during upward flow) - F(buoyancy)

Note: Buoyancy force also can be ignored for simplicity. The drag is quadratic drag, not stokes'. Consider the terminal velocity. Please devise the general way to calculate this.

 

[HallsofIvy]

Can you find the velocity of an object through fluid that is not moving? If so just add (vectorally) the velocity of the fluid.

 

[boneh3ad]

F (drag) ... F (force the fluid exerting on the object during upward flow)

These are the same force. This is just a frame of reference problem.