A 3D Comparison of Sprayed Liquid Flap Multiphase Modeling at Activation

Powered-lift concepts are often used to increase aerodynamic lift in specific scenarios like aircraft takeoff and landing or reduce lift during wind turbine high load conditions. A Sprayed Liquid Flap (SLF) is a novel powered-lift concept previously shown (computationally) to improve aerodynamic performance. Similar to jet flaps, fluid is expelled from the pressure surface, providing both increased lift and increased aerodynamic performance. Modeling SLFs requires coupled multiphase physics as each phase directly impacts not only each other, but also the aerodynamic forces on the airfoil. Previous 2D-SLF research efforts suggest aerodynamic performance can be well estimated using mid-fidelity Euler-Euler approaches. However, unsteady 3D aerodynamics of SLF activation have yet to be explored. This research effort focuses on comparing 3D, unsteady Euler-Euler multiphase methods against a similar Euler-Lagrange counterpart. Specifically, the effort seeks to understand how Euler-Euler models with particle drag-force coupling compares to Euler-Lagrange models with additional physics by including drag force coupling as well as particle collisions, coalescence, deformation, and breakup models. Results will be summarized and evaluated for aerodynamics as well as details of the multiphase flow will be explored.