functionNu_Laminar_Local_Developed_Rectangular

Information

Local heat transfer model for fully developed laminar and turbulent flow in rectangular ducts.

• The laminar region has been shown to be significantly impacted by the duct shape and wall boundary conditions but not the surface roughness.
• The turbulent region has been shown to be highly depenedent of surface roughness but not impacted by duct shape or wall boundary conditions.
• The characteristic dimension is defined as dimension = 4*crossArea/perimeter where "crossArea" is the cross sectional flow area and "perimeter" is the wetted perimeter.

Range of validity:

• fully developed pipe flow
• forced convection
• one phase Newtonian fluid
• constant wall temperature or constant heat flux in laminar region
• 0 ≤ Re ≤ ~2300, 0.1 ≤ Pr ≤ 1000, d/L ≤ 1
• Applies only to rectangular ducts in the laminar region.
• Laminar region is independent of surface roughness

References

1. Heat Transfer. Nellis and Klein. 2009

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