- #1

pistolpete

- 12

- 4

**Hello all, I have browsed this forum occasionally when I had questions and threads showed up on a search. I have been stumped by a problem, so I decided to create an account and see if anyone could help me out!**

1. Homework Statement

1. Homework Statement

A coal barge 1000 ft long and 100 ft wide is submerged in a depth of 12 ft in 60°F Water. It is being towed at a speed of 12 mph. Estimate the friction drag on the barge.

## Homework Equations

When treating the submerged part of the barge as Flat plate the equation for Drag Friction is :

D

_{F}=(1/2)*ρ*∪

^{2}*b*L*C

_{Df}

Since the submerged part of the barge would have three "faces" that are parallel to the flow direction (2 side faces of 1000ft*12ft, and one bottom face of 100ft*1000ft) would I add up the total area of the submerged faces parallel to the flow to use in the above equation?

The only examples I can find have only the bottom part of the plate, but they are floating so that seems logical to me.

## The Attempt at a Solution

Converted the 12 mph to ft/s then Calculated Reynolds # to find laminar/turb regions and use appropriate eqns to Find the C

_{Df}term

Using found values and properties of water @ 60°F solve for D

_{F}