Drag force on a 14mm cable in water flow up to 5km long

[Chee Lin]

Hi,

I have a raft that move along in a tunnel with the water flow (no propelling engine). A neutrally buoyant cable is attached to the device at the back to supply power for the apparatus on the raft. The cable is about 14mm in diameter and the max length of cable can be 5km. May I ask how can I calculate the drag force caused by the cable?

 

[zoki85]

Try this: http://scienceworld.wolfram.com/physics/CylinderDrag.html