1. The problem statement, all variables and given/known data 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 [Broken] 2. Relevant equations D_h = 4*A_x-section/P_wetted 3. 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?