For low drag and low complexity reasons, the use of enforced instationary aerodynamic phenomena has not been exploited on large aircraft so far. Modern fly-by-wire aircrafts with e.g. Advanced Dropped Hinged Flaps generally offer the architecture in which a periodical oscillation of the flaps is possible when an adapted actuator concept is applied. Either, this capability can be used for a periodic alteration of the spanwise lift distribution and with it the wake vortex centroid positions in order to accelerate exponential growth of natural vortex wake instabilities for fast vortex wake decay. Or, the constant periodic oscillation of flaps allows for higher deflection angles and respectively larger maximum lift coefficients compared to classical high-lift conditions with constant flap deflection angles due to the dynamic lift effect. Motivation of the former concept is a potential reduction of separation distances during approach whereas the latter concept might contribute to reducing airplane weight and exhaust fume emission or enable alternative approach trajectories. Within the research project BIMOD, funded by the German Aeronautic Research Program LuFo V-3, RWTH Aachen University and TU Munich cooperate on investigating the two concepts on a fundamental basis and on exploring the design space for respective technology implementation into current airliners. Preliminary results have shown that at a reduced frequency scope around 0.08±0.01 the wake vortex instability is excited, while the dynamic high-lift enhancement is largely dependent on the flap gap and kinematics.
Influence of Dynamic Flap Movement on Maximum Lift and Wake Vortex Evolution
2020
12 pages
Miscellaneous
Electronic Resource
English
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