docs: def h_boiling_Huang_Sheer(rhol, rhog, mul, kl, Hvap, sigma, Cpl, q, Tsat, 
                            angle=35.):
      r'''Calculates the two-phase boiling heat transfer coefficient of a 
      liquid and gas flowing inside a plate and frame heat exchanger, as
      developed in [1]_ and again in the thesis [2]_. Depends on the properties
      of the fluid and not the heat exchanger's geometry.
      
      .. math::
          h = 1.87\times10^{-3}\left(\frac{k_l}{d_o}\right)\left(\frac{q d_o}
          {k_l T_{sat}}\right)^{0.56}
          \left(\frac{H_{vap} d_o^2}{\alpha_l^2}\right)^{0.31} Pr_l^{0.33}
  
          d_o = 0.0146\theta\left[\frac{2\sigma}{g(\rho_l-\rho_g)}\right]^{0.5}\\
          \theta =  35^\circ
  
      Note that this model depends on the specific heat flux involved and
      the saturation temperature of the fluid.
              
      Parameters
      ----------
      rhol : float
          Density of the liquid [kg/m^3]
      rhog : float
          Density of the gas [kg/m^3]
      mul : float
          Viscosity of the liquid [Pa*s]
      kl : float
          Thermal conductivity of liquid [W/m/K]
      Hvap : float
          Heat of vaporization of the fluid at the system pressure, [J/kg]
      sigma : float
          Surface tension of liquid [N/m]
      Cpl : float
          Heat capacity of liquid [J/kg/K]
      q : float
          Heat flux, [W/m^2]
      Tsat : float
          Actual saturation temperature of the fluid at the system pressure, [K]
      angle : float, optional
          Contact angle of the bubbles with the wall, assumed 35 for refrigerants 
          in the development of the correlation [degrees]
  
      Returns
      -------
      h : float
          Boiling heat transfer coefficient [W/m^2/K]
  
      Notes
      -----
      Developed with 222 data points for R134a and R507A with only two of them
      for ammonia and R12. Chevron angles ranged from 28 to 60 degrees, heat 
      fluxes from 1.85 kW/m^2 to 10.75 kW/m^2, mass fluxes 5.6 to 52.25 kg/m^2/s,
      qualities from 0.21 to 0.95, and saturation temperatures in degrees Celcius
      of 1.9 to 13.04.
      
      The inclusion of the saturation temperature makes this correlation have
      limited predictive power for other fluids whose saturation tempratures
      might be much higher or lower than those used in the development of the
      correlation. For this reason it should be regarded with caution.
      
      As first published in [1]_ a power of two was missing in the correlation
      for bubble diameter in the dimensionless group with a power of 0.31. That
      made the correlation non-dimensional. 
      
      A second variant of this correlation was also published in [2]_ but with
      less accuracy because it was designed to mimick the standard pool boiling 
      curve.
      
      The correlation is reviewed in [3]_, but without the corrected power. It
      was also changed there to use hydraulic diameter, not bubble diameter.
      It still ranked as one of the more accurate correlations reviewed. 
      [4]_ also reviewed it without the corrected power but found it predicted
      the lowest results of those surveyed.
  
      Examples
      --------
      >>> h_boiling_Huang_Sheer(rhol=567., rhog=18.09, kl=0.086, mul=156E-6, 
      ... Hvap=9E5, sigma=0.02, Cpl=2200, q=1E4, Tsat=279.15)
      4401.055635078054
  
      References
      ----------
      .. [1] Huang, Jianchang, Thomas J. Sheer, and Michael Bailey-McEwan. "Heat 
         Transfer and Pressure Drop in Plate Heat Exchanger Refrigerant 
         Evaporators." International Journal of Refrigeration 35, no. 2 (March 
         2012): 325-35. doi:10.1016/j.ijrefrig.2011.11.002.
      .. [2] Huang, Jianchang. "Performance Analysis of Plate Heat Exchangers 
         Used as Refrigerant Evaporators," 2011. Thesis.
         http://wiredspace.wits.ac.za/handle/10539/9779
      .. [3] Amalfi, Raffaele L., Farzad Vakili-Farahani, and John R. Thome. 
         "Flow Boiling and Frictional Pressure Gradients in Plate Heat Exchangers.
         Part 1: Review and Experimental Database." International Journal of 
         Refrigeration 61 (January 2016): 166-84.
         doi:10.1016/j.ijrefrig.2015.07.010.
      .. [4] Eldeeb, Radia, Vikrant Aute, and Reinhard Radermacher. "A Survey of
         Correlations for Heat Transfer and Pressure Drop for Evaporation and 
         Condensation in Plate Heat Exchangers." International Journal of 
         Refrigeration 65 (May 2016): 12-26. doi:10.1016/j.ijrefrig.2015.11.013.
      '''
      do = 0.0146*angle*(2.*sigma/(g*(rhol - rhog)))**0.5
      Prl = Prandtl(Cp=Cpl, mu=mul, k=kl)
      alpha_l = thermal_diffusivity(k=kl, rho=rhol, Cp=Cpl)
      h = 1.87E-3*(kl/do)*(q*do/(kl*Tsat))**0.56*(Hvap*do**2/alpha_l**2)**0.31*Prl**0.33
      return h