Heat Transfer - Engineering

Q1:

A fluid is flowing inside the inner tube of a double pipe heat exchanger with diameter 'd'. For a fixed mass flow rate, the tube side heat transfer co-efficient for turbulent flow conditions is proportional to

A d0.8

B d-0.2

C d-1

D d-1.8

ANS:B - d-0.2

For turbulent flow conditions in the tube side of a double pipe heat exchanger, the tube side heat transfer coefficient (ht​) is proportional to a power of the tube diameter (�d). This relationship is expressed by the Dittus-Boelter equation for turbulent flow: .2ht​∝d−0.2 Therefore, the correct option is: d−0.2