[en] The Canadian SCWR (supercritical water-cooled reactor), which operates at supercritical pressure and temperature, is being developed at AECL. It is required that flow and heat-transfer characteristics at supercritical conditions be investigated. The heat-transfer modes in supercritical fluids were studied using heat-transfer data from supercritical CO₂ flow. Entrance-affected, normal and deteriorated heat transfer were defined using CO₂ data from upward flow in an 8 mm diameter tube. The threshold value for normal heat transfer was defined using normal and deteriorated heat-transfer data. Normal and deteriorated heat transfer correlations were separately derived using the relevant data. The correlations developed include the effect of flow condition parameters on heat transfer for different heat-transfer modes. (author)