Force and supporting particle image velocimetry measurements were performed on a plunging NACA 0012 airfoil at a Reynolds number of 10,000, at pre-stall, stall, and post-stall angles of attack. The lift coefficient for pre-stall and stall angles of attack at larger amplitudes showed abrupt bifurcations with the branch determined by initial conditions. With the frequency gradually increasing, ve...

A gradient-based Newton–Krylov algorithm for aerodynamic shape optimization is applied to lift maximization of a multi-element landing configuration. The governing flow equations are the two-dimensional compressible Navier–Stokes equations in conjunction with a one-equation transport turbulence model. The objective function gradient is computed via the discrete-adjoint method. The design exampl...

We analyze the modifications of the flow around a NACA 0015 airfoil when the flow is perturbed with an electrohydrodynamic (EHD) actuator. The device used consists of two bare electrodes flush mounted on the surface of the model operated in a discharge regime characterized by the formation of a plasma sheet contouring the body in the interelectrode space. In this study, we analyze the influence...

This paper deals with the optimization of a synthetic jet actuator parameters in the control flow around the NACA0015 airfoil at two angles of attack: 13° (i.e. the stall angle of NACA0015) and 16° (i.e. the post stall angle of NACA0015) to maximize the aerodynamic performance of the airfoil. Synthetic jet actuator is a zero mass flux-active flow control device that alternately injects and remo...

This paper describes the numerical analysis of a stall suppression system for helicopter rotors. The analysis employs a finite element method and includes advanced dynamic stall and vortex wake models. The stall suppression system is based on a transfer function matrix approach and uses blade root actuation to suppress stall directly. The rotor model used in this investigation is the UH-60A rot...

A low-order method is presented for aerodynamic prediction of wings operating at near-stall and post-stall flight conditions. The intended use in design, modeling, simulation. In this method, the flow separation due to stall modeled a vortex lattice framework as an effective reduction camber, or “decambering.” For each section wing, parabolic decambering flap, hinged location section, calculate...

This paper presents in-flight measurements of the interaction wing wake a stalled Slingsby T67 Firefly light aircraft with tailplane. Tailplane data was recorded by GoPro360 camera and analyzed using spatial correlation methods. The tailplane movement corresponding spectra indicate that aerodynamic shedding frequency closely matches resonant tailplane, resulting in significant excitation struct...