American Institute of Aeronautics and Astronautics 1 Multiscale Modeling of Active Flow Control for Fuselage Drag Reduction Jee Woong Kim 1 ,Lakshmi Sankar 2 , Byung-Young Min 3 , Nandita Yeshala 4 School of Aerospace Engineering, Georgia Tech, Atlanta, GA 30332-0150 And T. Alan Egolf 5 Sikorsky Aircraft Corporation, Stratford, CT, USA Multi-scale modeling of synthetic jet devices is employed to investigate the effect of active flow control (AFC) on fuselage drag reduction. The flow field in the vicinity of the synthetic jet devices was modeled using a Lattice Boltzmann equation (LBE) approach, while the external flow over the fuselage was modeled using a Reynolds-averaged Navier-Stokes (RANS) methodology. Computations with and without flow control also reported for flowfield around the isolated fuselage of ROBIN-mod7 model. The computed results, in the absence of flow control, have been compared with the measured data for ROBIN-mod7 model and show good agreement. Results from the CFD simulation with AFC using LB/NS coupled methodology indicate in an estimated 18% drag reduction. Nomenclature R = Reference rotor radius f = Excitation frequency, Hz W = Fuselage width (maximum) A cs = Fuselage cross-sectional area (maximum) q = Freestream dynamic pressure 2 1/2 U ρ ∞ ∞ ≡ C D = Drag coefficient ( 29 Drag / CS qA ≡ F + = Reduced frequency W/ f U ∞ ≡ U ∞ = Freestream velocity j U = Jet exit peak velocity I. Introduction primary contributor to the drag of a helicopter is the pressure drag associated with separation from bluff geometries such as the fuselage, pylons, rotor hubs, and landing gear. The large separated region may also affect flow over near-by aerodynamic surfaces (such as the rotors and stabilizers) increasing the interference drag. It is highly desirable to reduce the vehicle drag by delaying or suppressing of the flow separation. 1 Graduate Research Assistant, School of Aerospace Engineering, Georgia Institute of Technology, 270 Ferst Dr, Atlanta, Georgia 30332-0150, Student Member, AIAA. 2 Regents Professor and Associate Chair for Undergraduate Programs, School of Aerospace Engineering, Georgia Institute of Technology, 270 Ferst Dr, Atlanta, Georgia 30332-0150, AIAA Fellow, AIAA. 3 Senior Research Scientist, United Technologies Research Center, East Hartford, CT 06108. 4 Software Engineer, Design and Technology Solutions, Intel Corporation, 2501 NW 229 th Ave, Hillsboro, OR. 97124 5 Supervisor Aerodynamic Methodology, Sikorsky Aircraft, Stratford, CT. A 50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 09 - 12 January 2012, Nashville, Tennessee AIAA 2012-0075 Copyright © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. Downloaded by GEORGIA INST OF TECHNOLOGY on June 27, 2014 | http://arc.aiaa.org | DOI: 10.2514/6.2012-75