Question

2.) For a 20‐mm‐diameter tube with either water or unused engine oil flowing through it, find: a.)The mean velocity, hydrodynamic entry length, and thermal entry length for each of the fluids with a temperature of 300 K if the mass flow rate is 0.01 kg/s. b.)The mass flow rate, hydrodynamic entry length, and thermal entry length for each fluid at 400 K and a mean velocity of 0.02 m/s.

Answer 1

Answer:

a.) The mean velocity = 0.0318 m/s

    The  hydrodynamic entry length = 0.636 m

     The  thermal entry length = 0.004 m

(b) The mass flow rate = 0.0051 kg/s

    The hydrodynamic entry length = 0.028 m

     The  thermal entry length = 1.419 m

Explanation:

See the attached files for the calculation.