Intake lip separation control using plasma actuators

Introduction The next-generation aircraft engines operate at a high bypass and low fan pressure ratios. Such modern architectures will have the key benefits of improving the fuel burn and reducing the emissions and noise. With increasing bypass ratio, the diameter of the engine inlet increases and shorter intakes (with as small an outer diameter as possible) are required to compensate for the subsequent increase in the weight and drag. However, the sharper lips of shorter intakes have a reduced incidence tolerance and the flow is prone to: rapid acceleration around the intake lip, relaminarization, flow separation and transition to turbulence specifically under off-design conditions like high incidence/crosswinds (see Figure 1(a)). The current study aims to capture the flow separation over the intake-lip under crosswinds using eddy resolving simulations. Subsequently, the effect of plasma flow control will be investigated. These devices can either induce additional disturbances or inject momentum into the separated shear layer depending on their orientation. It helps in suppressing separation thereby improving the performance of the intakes.