NASA Dryden Flight Research Center has developed a flush airdata sensing (FADS) system on a sharp-nosed, wedge-shaped vehicle. This paper details the design and calibration of a real-time angle-ofattack estimation scheme developed to meet the onboard airdata measurement requirements for a research vehicle equipped with a supersonic-combustion ramjet engine. The FADS system has been designed to ...

Single dielectric barrier discharge plasma actuators have been used to control flow separation in a large number of applications. An often used configuration involves spanwise-oriented asymmetric electrodes that are arranged to induce a tangential wall jet in the mean flow direction. For the best effect, the plasma actuator is placed just upstream of where the flow separation will occur. This a...

This paper presents an attitude control algorithm for a Reusable Launch Vehicle (RLV) with a low lift/drag ratio (L/D < 0.5), in the presence of external disturbances, model uncertainties, control output constraints and the thruster model. The main novelty of proposed control strategy is a new combination of the attitude control methods included backstepping, dynamic inversion and adaptive cont...

Cl = section lift coefficient c = local chord length D = fading-memory constant G = nondimensional circulation l = section lift force/length m = number of points used in sine series expansion of circulation function N = consecutive iterations convergence parameter r = perpendicular distance from vortex tol = iteration relative tolerance of conversion U1 = freestream velocity magnitude w = downw...

In a previous paper, we addressed the problem of choosing constant values of altitude, speed, and angle of attack such that the orbital plane change during hypersonic flight is maximized for a fixed amount of propellant consumption. In the present paper, the restrictions of constant speed and angle of attack are removed. Necessary conditions for solutions to the resulting optimal control proble...

The downstroke-to-upstroke transition of many insects is characterized by rapid wing rotation. The aerodynamic consequences of these rapid changes in angle of attack have been investigated using a mechanical model dynamically scaled to the Reynolds number appropriate for the flight of small insects such as Drosophila. Several kinematic parameters of the wing flip were examined, including the sp...

A hydrofoil turbine with simultaneous heaving and pitching is found to have an ability achieve a high power extraction. An OpenFOAM-based numerical model combined non-conformal sliding interface employed study the extraction efficiency of two-dimensional single hydrofoil. The developed validated published experimental results. For Re = 500,000, energy efficiencies are mapped in frequency amplit...