type FreeConvectionCorrelation = enumeration(vertical_plate_ASHRAE "Churchill & Chu correlation for a flat vertical plate", vertical_plate_Recknagel "Recknagel correlation for a flat vertical plate", ground_ASHRAE "Lloyd and Moran correlation for a horizontal ground plate", ceiling_ASHRAE "Lloyd and Moran correlation for a horizontal ceiling plate", horizontal_cylinder_ASHRAE "Churchill & Chu correlation for the external flow around an horizontal cylinder", Constant "Constant convective heat transfer coefficient");