Extraction of Energy using Ram Air Turbines An Industrial Approach

Abstract

Ram Air Turbines (RATs) were considered for generation of emergency electrical energy in a prototype developmental aircraft. Due to integration of new systems on the aircraft, requirement of additional electrical energy was felt in failure mode (failure of main alternator) during approach and landing phases of the flight. There was also an additional requirement of generating drag during the operation of RAT in order to execute steeper approaches. A research work was undertaken for proving the concept and pave way for further studies. This research work was mainly undertaken to study the performance of three high drag RAT models using Wind Tunnel experiments. In order to undertake this research, a detailed literature review was undertaken on areas where similar work has been carried out or attempted. The research work also included setting up the wind tunnel for the measurement of forces, moments, electrical voltage and RPM. To estimate the wind speeds expected during the required phase of flight where the RAT was expected to be deployed, Real Time Simulation was carried out for various configurations of the aircraft. The results were validated using flight trial data. During the course of research, an innovative method of estimating closure velocity between the RAT driven tanker aircraft drogue basket and the fighter aircraft in-flight refuelling probe was evolved. This innovation paved way for the certification of the Air-to-Air newline