Heat transfer characteristics of engine inlet swirl nozzle anti-icing system

To investigate the heat transfer characteristics of impinging jet and annular flow in the aero-engine inlet swirl nozzle anti-icing system, a numerical simulation method is conducted to analyze the coupled internal-external flow and heat transfer within the inlet anti-icing cavity. Dimensionless characteristic parameters are established for evaluating the swirl nozzle anti-icing system performance. The influence of Nozzle Jet Angle (NJA), Nozzle Position (NP), and Nozzle Area Ratio (NAR) on surface temperature distribution and uniformity at the inlet lip are investigated. The regular relationship formula between the average Reynolds number and the Nusselt number was obtained for swirl nozzle anti-icing flow and heat transfer. Results show that: Increasing the hot air jet distance enhances the swirl nozzle anti-icing system performance; changing NJA and NP slightly offset toward the internal flow channel side of the inlet significantly improves temperature uniformity of the lip. Increasing the area of the orifice which is adjacent to the inlet, improves temperature uniformity of the lip but simultaneously raises the risk of overheating of the inlet lip.