E5.5 Forced Convection through Circular Tubes

Example 5.5: Water is flowing through a tube having internal diameter 1.334" at a rate of 10000 lb/hr. It is heated from 80 °F to 120 °F in a counter-current arrangement. Find the heat transfer coefficient (h_i) if the following data apply:

Bulk temperature, t_b, = 100 °F

Specific heat, c, = 0.998 Btu/(lb·°F); density, ρ = 62.0 lb/ft³;

Absolute viscosity, μ = 1.65 lb/(ft·hr); thermal conductivity, k = 0.363 Btu/(hr·ft·°F);

Solution: Water is flowing through a circular tube. Heat transfer coefficient depends upon the value of Reynolds number and Graetz number.

The velocity of the fluid, V, can be found once the cross-sectional area, a, is known.

Reynolds number, Re:

Prandtl number, Pr:

Nusselt number, Nu: Appropriate relationship when Re is greater than 10000, so the following correlation will apply:

Film transfer coefficient, h: