Unsteady load mitigation through a passive trailing-edge flap

There are a wide range of applications in which it is desirable to mitigate unsteady load fluctuations while preserving mean loading. This often achieved with active control systems, but passive systems sometimes more for enhancing reliability. the case, example, wind and tidal turbines, where loading limits fatigue life turbine results power peaks at generator. Here, we consider mitigation that can be through foil trailing-edge flap connected via torsional spring. We develop theoretical model show preload tuned preserve The spring moment maximises approximately constant, fluctuation reduction linearly proportional ratio full chord foil. verify this relationship water tunnel tests hinge 25% from trailing edge. As theoretically predicted, measure up 25%, without any variation load. In highly flow conditions, when boundary layer separation occurs, decreases. Overall conclude flaps effective alleviating their effectiveness depends on size relative