Specify the radius in mm to the centerline of a 90 bend in a 25 mm OD × 2.0 mm wall copper tube to achieve the minimum energy loss. For such a bend carrying 250 L/min of water at 80°C, compute the energy loss. Compare the results with those of Problem 10.41.

In Problem

A 25 mm OD × 2.0 mm wall copper tube supplies hot water (80°C) to a washing system in a factory at a flow rate of 250 L/min. At several points in the system, a 90° bend is required. Compute the energy loss in each bend if the radius to the outside of the bend is 300 mm.