docs: def turbulent_Sandall(Re, Pr, fd):
      r'''Calculates internal convection Nusselt number for turbulent flows
      in pipe according to [2]_ as in [1]_.
  
      .. math::
          Nu = \frac{(f/8)RePr}{12.48Pr^{2/3} - 7.853Pr^{1/3} + 3.613\ln Pr + 5.8 + C}\\
          C = 2.78\ln((f/8)^{0.5} Re/45)
  
      Parameters
      ----------
      Re : float
          Reynolds number, [-]
      Pr : float
          Prandtl number, [-]
      fd : float
          Darcy friction factor [-]
  
      Returns
      -------
      Nu : float
          Nusselt number, [-]
  
      Notes
      -----
      Range according to [1]_ is 0.5< Pr ≤ 2000  and 10^4 ≤ Re ≤ 5*10^6.
  
      Examples
      --------
      >>> turbulent_Sandall(Re=1E5, Pr=1.2, fd=0.0185)
      229.0514352970239
  
      References
      ----------
      .. [1] Rohsenow, Warren and James Hartnett and Young Cho. Handbook of Heat
         Transfer, 3E. New York: McGraw-Hill, 1998.
      .. [2] Sandall, O. C., O. T. Hanna, and P. R. Mazet. “A New Theoretical
         Formula for Turbulent Heat and Mass Transfer with Gases or Liquids in
         Tube Flow.” The Canadian Journal of Chemical Engineering 58, no. 4
         (August 1, 1980): 443–47. doi:10.1002/cjce.5450580404.
      '''
      C = 2.78*log((fd/8.)**0.5*Re/45.)
      return (fd/8.)**0.5*Re*Pr/(12.48*Pr**(2/3.) - 7.853*Pr**(1/3.) 
                                 + 3.613*log(Pr) + 5.8 + C)