Repeat Problem 40, using the same information except that the inside tube is insulated rather than maintained at constant temperature. Problem 40 A 3 m long annular fl ow area consists of a 1/2...

Repeat Problem 40, using the same information except that the inside tube is insulated rather than maintained at constant temperature.

Problem 40

A 3 m long annular fl ow area consists of a 1/2 standard tube placed within a 1 standard tube, both type M and made of copper. Air fl owing through the annulus receives heat from a vaporizing refrigerant in the inner tube that keeps the outside diameter of the inner tube at 10°C. Th e outer tube is submerged in ice, which begins melting and maintains the inside-wall temperature of the outer tube at 0°C. A hydrodynamically developed fl ow of air at 125°C enters the annulus at a mass fl ow rate of 1 × 10–3 kg/s. Determine the expected outlet temperature. Calculate also the friction factor and pressure drop.