docs: def Nu_vertical_cylinder_McAdams_Weiss_Saunders(Pr, Gr, turbulent=None):
      r'''Calculates Nusselt number for natural convection around a vertical
      isothermal cylinder according to the results of [1]_ and [2]_ correlated by
      [3]_, as presented in [4]_, [5]_, and [6]_.
  
      .. math::
          Nu_H = 0.59 Ra_H^{0.25},\; 10^{4} < Ra < 10^{9}
  
          Nu_H = 0.13 Ra_H^{1/3.},\; 10^{9} < Ra < 10^{12}
  
      Parameters
      ----------
      Pr : float
          Prandtl number [-]
      Gr : float
          Grashof number [-]
      turbulent : bool or None, optional
          Whether or not to force the correlation to return the turbulent
  		 result; will return the laminar regime if False; leave as None for
          automatic selection
      Returns
      -------
      Nu : float
          Nusselt number, [-]
  
      Notes
      -----
      Transition between ranges is not smooth. If outside of range, no warning is
      given. For ranges under 10^4, a graph is provided, not included here.
  
      Examples
      --------
      >>> Nu_vertical_cylinder_McAdams_Weiss_Saunders(.7, 2E10)
      313.31849434277973
  
      References
      ----------
      .. [1] Weise, Rudolf. "Warmeubergang durch freie Konvektion an
         quadratischen Platten." Forschung auf dem Gebiet des Ingenieurwesens
         A 6, no. 6 (November 1935): 281-92. doi:10.1007/BF02592565.
      .. [2] Saunders, O. A. "The Effect of Pressure Upon Natural Convection in
         Air." Proceedings of the Royal Society of London A: Mathematical,
         Physical and Engineering Sciences 157, no. 891 (November 2, 1936):
         278-91. doi:10.1098/rspa.1936.0194.
      .. [3] McAdams, William Henry. Heat Transmission. 3E. Malabar, Fla:
         Krieger Pub Co, 1985.
      .. [4] Morgan, V.T., The Overall Convective Heat Transfer from Smooth
         Circular Cylinders, in Advances in Heat Transfer, eds. T.F. Irvin and
         J.P. Hartnett, V 11, 199-264, 1975.
      .. [5] 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.
      .. [6] Boetcher, Sandra K. S. "Natural Convection Heat Transfer From
         Vertical Cylinders." In Natural Convection from Circular Cylinders,
         23-42. Springer, 2014.
      '''
      Ra = Pr*Gr
      if turbulent or (Ra > 1E9 and turbulent is None):
          return 0.13*Ra**(1/3.)
      else:
          return 0.59*Ra**0.25