Vertical Low-Flow Factor - A minus sign refers to downward flow
function K_8 input SIadd.MassFlux G "Mass flux"; input SI.Density rho_lsat "Fluid saturation density"; input SI.Density rho_vsat "Vapor saturation density"; input SIadd.NonDim x_abs "Absolute quality"; output Real K "Correction factor"; end K_8;