A Numerical Evaluation of Sprayed Liquid Flap Airfoil Aerodynamics: Euler-Lagrange Method

The Sprayed Liquid Flap (SLF) is a novel powered lift concept which relies on atomized liquid jets to modify the external aerodynamics about a lifting surface. Assessments of SLF to date have used an Euler-Euler model to provide initial performance predictions. Such a model may have inherent gaps in the detailed aerodynamic interactions associated with spray structure, droplet break-up/coalescence, and spray-wake dispersion. Such aerodynamic features are evaluated in this work. This research finds that when SLF concepts are explored with a higher fidelity Euler-Lagrange method, some of its benefits are reduced. Specifically, the results found that across a range of jet momentum coefficients, the aerodynamic lift is up to 3.7% reduced, and drag is up to an order of magnitude increased compared to the previously used Euler-Euler approach. Overall, the results continue to show that SLFs have potential as a powered lift concept and indicate promise in the device.