Section 4: Forced Convection Flow Across Single Circular Cylinders and Tube Bundles

 

 

D = cylinder diameter, u_m = free-stream velocity, all properties at fluid bulk mean temperature. Correction for temperature dependent fluid properties see section 4-4.

4-1 Smooth Circular Cylinder

 

Valid over the ranges 10 < Re_l < 10⁷ and 0.6 < Pr < 1000.

4-2 Tube Bundle

Transverse pitch ratio

Longitudinal pitch ratio

Void ratio for b > 1

for b < 1

Nu_0,bundle = f_ANu_l,0 (Gnielinski)

Nu_l,0 according to section 4-1 with instead of Re_l.

Arrangement factor f_A depends on tube bundle arrangement.

In line arrangement:

Eq. (23)

 

Staggered arrangement:

Eq. (24)

 

4-3 Finned Tube Bundle

In-line tube bundle arrangement:

Eq. (25)

Staggered tube bundle arrangement:

Eq. (26)

 

4-4 Effects of Property Variation with Temperature

Liquids:

Eq. (27)

 

Eq. (28)

Subscript w: at wall temperature, without subscript: at mean fluid temperature.

Gases:

Eq. (29)

 

Eq. (30)

Temperatures in Kelvin.