Question

In a building mechanical system, water at 75˚C is flowing through 1 inch Type K Copper tubing. Determine the largest flow rate (Q), in litres/minute that will result in laminar flow.

Answer 1

Here ,In a building mechanical system we have,

• 1 Inch type K copper tubing,for which

Outside diameter,D​​​​​​o = 1.125 in

Inside diameter,D​​​​​​i = 0.995 in

Cross sectional area of bore, A = 0.778 in²

• Water at 75 o C, We have

Density of water,ρ = 60.8556 lbm/ft³

Viscosity of water, μ = (0.000007863) × 32.14) lbm.s/ft²

μ= 2.527×10-4 lbm.s/ft²

Now,As it has heen asked to calculate the maximum discharge resulting a laminar flow,thus we have to find the maximum velocity for which the flow remain laminar,i.e When Reynolds number equals to 2000.

Thus, Maximum Discharge is given by,