Powering quieter helicopter flight
The green rotorcraft research consortium in Europe's Clean Sky research programme is developing technologies to greatly reduce rotor noise and fuel consumption in helicopters. The main rotor and its blades are a main contributor due to their inability to adapt to flight conditions to produce a favourable aerodynamic profile. This inflexibility also has an impact on performance, affecting the possible flight envelope, speed and range. Since real-time adaptation of blades is currently not technically feasible, other options have been considered. Synthetic jets produced by actuators in cavities inside the blade can blow or suck air, generating turbulences that actually reduce undesirable conditions. Piezo actuators are a promising technology and so the 'Piezo power supply module for piezo actuator bench' (PPSMPAB) project, funded by the EU, set out to develop a piezo power supply module to drive these powerful actuators. PPSMPAB sought to develop a piezo power supply producing the highest required power with very high efficiency for driving piezo actuators in helicopter applications. Scientists conducted a feasibility study looking at potential demonstrators of the power cores and the main trade-offs of various technologies. From the insight obtained, they created a detailed design including the electronic functions and associated packaging for the embedded solution. In the end, the team produced a final piezo power supply prototype meeting technology readiness level 4. Testing and characterisation have pointed the way to future development work that will be focused on integration of a piezo power supply in helicopters. Piezo actuators have the potential to achieve quieter and greener helicopters. PPSMPAB has made an important contribution to development of an associated power supply for the high-power, high-efficiency system. Along the way, individual components for the power electronics, including the most powerful piezo amplifier on the market, are accomplishments in themselves.
Keywords
Rotorcraft, noise, blades, power supply, piezo actuator
