The aerodynamic acceptance test involves the Flat Plate Elimination Test (FPET), which measures the Boundary Layer Displacement Thickness, BLDT, of the air above the fluid film, the latter being related to lift loss. The test is described in AS5900. The purpose of the aerodynamic test is to ensure that the fluid left on the wings, at the time of take-off, will not significantly interfere with the lift capabilities of the aircraft. The acceptable level of lift loss was evaluated at 5.25%, as measured on a 2D model of a Boeing 737-200 ADV wing section at 60% span. The flat-plate setup consists of a rectangular duct inserted in the test section of the AMIL cold wind tunnel, where the airflow and fluid can be maintained at a constant temperature, from 5 down to -45°C.
High-Speed Ramp Aerodynamic Tests
The High-Speed Ramp, Flat-Plate Elimination Test (FPET-HR) is an international standard laboratory test procedure for assessing the aerodynamic performance of aircraft ground de/anti-icing fluids. The purpose of this test is to ensure that the fluid left on the wings, at the time of take-off, will not significantly reduce with the lift capability of the aircraft.
The FPET-HR is performed between 0 and -45°C. The high-speed ramp has an acceleration rate of 2.6 m/s2 and reaches a maximum air velocity of 65 m/s.
Low-Speed Ramp Aerodynamic Tests
This test is similar to the high-speed ramp aerodynamic test except that the fluid is subjected to an airflow simulating commuter-type aircraft ground roll (e.g. turboprop): with low rotation speed, wind acceleration of 2.1 m/s2, and maximum air velocity of 35 m/s.