Novel Induced Drag Predictions using CFD; Applications to Sprayed Liquid Flaps*

A novel approach to estimating induced drag using Computational Fluid Dynamics (CFD) has recently been proposed. The proposed methodology involves calculating the induced drag of finite wings from viscous CFD simulations by means of momentum and energy balances. The application of this approach was previously limited to attached flows which were validated against analytic solutions. The present effort aims to apply this methodology to finite wings equipped with a Sprayed Liquid Flap (SLF). SLFs modify the conventional Jet Flap by replacing the gaseous jet with an atomized liquid spray. The addition of this second fluid phase introduces complex aerodynamic interactions with the freestream which are not readily assessable using a momentum-balance analysis. Hence, the application of this novel, energy-balance approach is well suited to gain insight into these complex phase interactions. This report aims at decomposing the drag provided by momentum conservation into viscous and inviscid criteria by means of a control volume, energy-balance analysis. Furthermore, an attempt is made to qualitatively describe the complex fluid interactions due to the injection of the liquid jet.