What are the assumptions and limitations of the Dittus-Boelter equation?

The Dittus-Boelter equation is used to calculate the Nusselt number of turbulent flow in smooth pipes.

Note: The Dittus-Boelter equation is obtained by modifying Colburn equation. The Colburn equation is obtained by modifying Chilton-Colburn analogy.

The Dittus-Boelter equation is used to calculate the Nusselt number of turbulent flow in smooth pipes.

Note: The Dittus-Boelter equation is obtained by modifying Colburn equation. The Colburn equation is obtained by modifying Chilton-Colburn analogy.