Active Flow Control Devices for Wing Load Alleviation

Abstract

Active flow control has not found wide application in aircraft due to a combination of technical challenges, costs, and small impact on overall aircraft performance. Future applications, like alleviating dynamic loads, could be made possible through continuous improvement of flow control methods and increasingly restrictive environmental regulations. To date, few studies deal with active flow control for load alleviation on transport aircraft wings at high Reynolds and Mach numbers. A systematic assessment of flow control methods for load alleviation is therefore carried out. Multiple flow actuation schemes for gust load alleviation through dynamic lift reduction are investigated over a range of flight conditions using two-dimensional Reynolds-averaged Navier–Stokes simulations. Unsteady gust interactions with a clean airfoil produce target loads for load alleviation. Actuator performance is consequently evaluated based on an engineering model. The results show that select fluidic actuators outperform micro-mechanical actuators at low flight speeds and feature similar steady load response as trailing edge flaps for the entire flight envelope. The Coandă jet features relatively low mass flow requirements, but necessitates minimal dual-slot blowing for baseline performance recovery. The results of this study highlight the potential of fluidic flow control schemes for implementation into a dedicated gust load alleviation system.