PROBLEM 1

Problem 10.5. A circular heater plate with 80 mm diameter is placed in a tank containing liquid

nitrogen at 1 MPa pressure and 80 K temperature. The upward facing side of the plate is maintained at

100 K. Find the heat transfer rate between the heater and liquid nitrogen.

For liquid nitrogen properties, you may assume:

p = 745.6 kg/m³, Cp = 2.122; ‚μ = 104 x 10-6N.2, k = 0.122-

kJ

kg.K

m².

0.0072 K-¹.

W

m.K

, Pr = 1.80,ß =