docs: def turbulent_Petukhov_Kirillov_Popov(Re=None, Pr=None, fd=None):
      r'''Calculates internal convection Nusselt number for turbulent flows
      in pipe according to [2]_ and [3]_ as in [1]_.
  
      .. math::
          Nu = \frac{(f/8)RePr}{C+12.7(f/8)^{1/2}(Pr^{2/3}-1)}\\
          C = 1.07 + 900/Re - [0.63/(1+10Pr)]
  
      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 ≤ 10^6  and 4000 ≤ Re ≤ 5*10^6
  
      Examples
      --------
      >>> turbulent_Petukhov_Kirillov_Popov(Re=1E5, Pr=1.2, fd=0.0185)
      250.11935088905105
  
      References
      ----------
      .. [1] Rohsenow, Warren and James Hartnett and Young Cho. Handbook of Heat
         Transfer, 3E. New York: McGraw-Hill, 1998.
      .. [2] B. S. Petukhov, and V. V. Kirillov, "The Problem of Heat Exchange
         in the Turbulent Flow of Liquids in Tubes," (Russian) Teploenergetika,
         (4): 63-68, 1958
      .. [3] B. S. Petukhov and V. N. Popov, "Theoretical Calculation of Heat
         Exchange in Turbulent Flow in Tubes of an Incompressible Fluidwith
         Variable Physical Properties," High Temp., (111): 69-83, 1963.
      '''
      C = 1.07 + 900./Re - (0.63/(1. + 10.*Pr))
      return (fd/8.)*Re*Pr/(C + 12.7*(fd/8.)**0.5*(Pr**(2/3.) - 1.))