CFD Simulations of Landing and Takeoff CRM High-Lift Configurations

Numerical simulations have been performed for a conventional high-lift version
of the Common Research Model (CRM) model corresponding to landing and take-
off configurations. Computed values of lift and drag for the landing configuration
are compared with the experimental data acquired in the 14- by 22-Foot Subsonic
Tunnel (14×22) at the NASA Langley Research Center (LaRC). Simulations replicated the experimentally observed improvements in the lift characteristics in the
presence of a nacelle chine. Flow visualization images indicate that vortices generated by the nacelle chine reduce flow separation regions on the upper surface
of the wing at higher angles of attack. Based on such observations, the take-off
configuration considered is also equipped with a nacelle chine, and testing of this
configuration is planned in the 14×22 tunnel in near future. Preliminary solutions
are also presented to explore the feasibility of using a localized flap gap blowing
(LFGB) active flow control concept for improving the aerodynamic performance
at take-off conditions.