Reverse thrust calibration test technology of turbofan nacelle simulator

To meet the demand of reverse thrust wind tunnel tests for large aircraft, a kind of reverse thrust calibration test technology of turbofan nacelle simulator was developed in China Aerodynamics Research and Development Center. The reverse thrust calibration test platform was constructed in FL-12 low speed wind tunnel. Thrust of the nacelle was measured by the thrust balance. Air-line bridges were used to reduce the impact of air-line tube on the balance. In order to eliminate effects of induction of inlet and exhaust flow of the nacelle on wind tunnel flow and prevent the potentially dangerous re-ingestion of reverse exhaust flow, the wind tunnel test section was blocked by a plate between the inlet and outlet of the nacelle. A reverse thrust calibration test method and a test result correcting method were developed. In ordered to verify reliability of the reverse thrust calibration test technology, a reverse thrust calibration test of a turbine simulator nacelle and a full model reverse thrust wind tunnel test were conducted in FL-12 and FL-13 low speed wind tunnel respectively. The test results indicated that, with the increase of nozzle pressure ratio, the differences between calculation and calibration of mass flow and velocity of the reverse thrust nacelle decreased gradually; the calibration test accuracy was better than 0.5%, which can meet the accuracy need of reverse thrust wind tunnel test.