docs: def turbulent_Gowen_Smith(Re, Pr, fd):
      r'''Calculates internal convection Nusselt number for turbulent flows
      in pipe according to [2]_ as shown in [1]_.
  
      .. math::
          Nu = \frac{Re Pr (f/8)^{0.5}} {4.5 + [0.155(Re(f/8)^{0.5})^{0.54}
          + (8/f)^{0.5}]Pr^{0.5}}
  
      Parameters
      ----------
      Re : float
          Reynolds number, [-]
      Pr : float
          Prandtl number, [-]
      fd : float
          Darcy friction factor [-]
  
      Returns
      -------
      Nu : float
          Nusselt number, [-]
  
      Notes
      -----
      0.7 ≤ Pr ≤ 14.3 and 10^4 ≤ Re ≤ 5E4 and 0.0021 ≤ eD ≤ 0.095
  
      Examples
      --------
      >>> turbulent_Gowen_Smith(Re=1E5, Pr=1.2, fd=0.0185)
      131.72530453824106
  
      References
      ----------
      .. [1] Rohsenow, Warren and James Hartnett and Young Cho. Handbook of Heat
         Transfer, 3E. New York: McGraw-Hill, 1998.
      .. [2] Gowen, R. A., and J. W. Smith. “Turbulent Heat Transfer from Smooth
         and Rough Surfaces.” International Journal of Heat and Mass Transfer 11,
         no. 11 (November 1968): 1657–74. doi:10.1016/0017-9310(68)90046-X.
      '''
      return Re*Pr*(fd/8.)**0.5/(4.5 + (0.155*(Re*(fd/8.)**0.5)**0.54 + (8./fd)**0.5)*Pr**0.5)