Forced Convection Coefficient / Pipe External Flow

These calculations run in your web browser, using embedded Javascripts; which means that you must set your browser to allow Javascripts .

The equation used here for the average Nusselt number over the outside wall of a pipe with fluid flowing passing over it:
image
and the average heat transfer coefficient is .... ...

H = NuD * [ k / D ]

units are shown in the table below.

Notes:

  • The units of input variable Cp are kJ/kg/deg K. For example Cp(air) = 1.005
  • Gas constant R for air is .287 kJ/kg/deg K
  • External fluid density (rho) is calculated using the Ideal Gas equation.
  • Re(D) = rho * Vel * D / mu
  • Pipe external diameter is input in mm and converted to meters internally.
  • For non-round pipes and ducts, use the hydraulic diameter for D.


    • Calculator

  • Pipe Diameter D (mm)

  • Velocity (m/s)

  • Gas Constant, R

  • Gas Conductivity, k (W/m/k)

  • Gas Cp (kJ/kg/degK)

  • Gas Viscosity mu (kg/m/s)

  • Gas Temperature T (deg C)

  • Gas Inlet Static Pressure P (kPa)


  • Density

  • Prandtl

  • Re(D)

  • Nu(D)

  • HTC(average)



    • page written by Dave Leo