docs: def Nu_vertical_cylinder_Popiel_Churchill(Pr, Gr, L, D,
                       Nu_vertical_plate_correlation=Nu_vertical_plate_Churchill):
      r'''Calculates Nusselt number for natural convection around a vertical
      isothermal cylinder according to [1]_, also  presented in [2]_.
  
      .. math::
          \frac{Nu}{Nu_{L,fp}} = 1 + B\left[32^{0.5}Gr_L^{-0.25}\frac{L}{D}\right]^C
  
          B = 0.0571322 + 0.20305 Pr^{-0.43}
  
          C = 0.9165 - 0.0043Pr^{0.5} + 0.01333\ln Pr + 0.0004809/Pr
  
      Parameters
      ----------
      Pr : float
          Prandtl number [-]
      Gr : float
          Grashof number with respect to cylinder height [-]
      L : float
          Length of vertical cylinder, [m]
      D : float
          Diameter of cylinder, [m]
      Nu_vertical_plate_correlation : function, optional
          Correlation for vertical plate heat transfer
  
      Returns
      -------
      Nu : float
          Nusselt number, [-]
  
      Notes
      -----
      For 0.01 < Pr < 100. Requires a vertical flat plate correlation.
      Both [2], [3] present a power of 2 instead of 0.5 on the 32 in the equation,
      but the original has the correct form.
  
      Examples
      --------
      >>> Nu_vertical_cylinder_Popiel_Churchill(0.7, 1E10, 2.5, 1)
      228.8979005514989
  
      References
      ----------
      .. [1] Popiel, C. O., J. Wojtkowiak, and K. Bober. "Laminar Free Convective
         Heat Transfer from Isothermal Vertical Slender Cylinder." Experimental
         Thermal and Fluid Science 32, no. 2 (November 2007): 607-613.
         doi:10.1016/j.expthermflusci.2007.07.003.
      .. [2] Popiel, Czeslaw O. "Free Convection Heat Transfer from Vertical
         Slender Cylinders: A Review." Heat Transfer Engineering 29, no. 6
         (June 1, 2008): 521-36. doi:10.1080/01457630801891557.
      .. [3] Boetcher, Sandra K. S. "Natural Convection Heat Transfer From
         Vertical Cylinders." In Natural Convection from Circular Cylinders,
         23-42. Springer, 2014.
      '''
      B = 0.0571322 + 0.20305*Pr**-0.43
      C = 0.9165 - 0.0043*Pr**0.5 + 0.01333*log(Pr) + 0.0004809/Pr
      Nu_fp = Nu_vertical_plate_correlation(Pr, Gr)
      return Nu_fp*(1 + B*(32**0.5*Gr**-0.25*L/D)**C)