Question on Equivalent/Hydraulic Diameter

[ganondorf29]

Homework Statement

Hello, I have a question on how to calculate the equivalent/hydraulic diameter for a problem that I'm doing.

The problem states that I should use the cross-sectional flow area shown with an equivalent diameter based upon a closed rectangle (entire perimeter)

[PLAIN]http://img196.imageshack.us/img196/3968/finsm.jpg

Homework Equations

D_h = 4*A_x-section/P_wetted

The Attempt at a Solution

So I did:

A_xsection = 6cm * 1cm = 6cm^2
Since there are three slits, I multiplied that by 3 to get: 18cm^2

The perimeter was 6+6+1+1 = 14cm
I also multiplied this by 3 to get: 42cm


D_h = 4*(18cm^2)/42cm = 1.714 cm = 0.01714 m


Is this right?

 

[edgepflow]

Looks OK to me.