Birds have the impressive ability to gracefully ‘swim’ through the air while executing aerobatic maneuvers that routinely defy modern aeronautical and control engineering, consistently reminding us that the skies are truly their playground. Many of these animals are masters at exploiting post-stall pressure drag to execute maneuvers with unprecedented speed and precision, with nowhere near the ...

A 1990 research program that focused on the development of advanced aerodynamic control effectors (AACE) for military aircraft has been reviewed and summarized. Data are presented for advanced planform, flow control, and surface contouring technologies. The data show significant increases in lift, reductions in drag, and increased control power, compared to typical aerodynamic designs. The resu...

To reduce the negative impacts of stall and surge on compressor performance, a novel combined casing treatment (CCT) structure with axial skewed slots injection groove is proposed in this paper. The aerodynamic as well mechanisms loss generation, transonic NASA Rotor 67 are investigated numerically. simulation results indicate that, compared individual method, CCT works effectively regard to op...

Thrust vector control (TVC) might be used to aircraft at large altitudes and in post-stall conditions when aerodynamic surfaces are ineffective. This study demonstrated that the implementation of TVC on high-speed is a reasonable solution an alternative compared complicated reaction system or surfaces. The numerical flight dynamics model X-15 experimental was developed implemented MATLAB/Simuli...

Abstract Aiming at the critical flutter problem of wind turbine blades, which is between classical and stall flutter, a suppression scheme based on radial basis function (RBF) neural network friction compensation backstepping presented. The structure model typical 2D section bending twist spring-mass-damper, rotor variable exciter second-order with disturbance incorporated to control blade. A m...

This numerical study reports the aerodynamic properties of a hybrid airship. The airships were designed by combining two semi-ellipsoids with semi-discoid as base model. From model, three different geometrics identified to their characteristics. A circular slot was provided between pressure side and suction objective this realize flow behavior, characteristics, stability such slotted flying veh...

The paper contributes towards the development of a unified control approach for longitudinal aircraft dynamics with large flight envelopes. Prior to the control design, we analyze the existence and the uniqueness of the equilibrium orientation along a reference velocity. We show that shape symmetries and aerodynamic stall phenomena imply the existence of the equilibrium orientation irrespective...

It is well known that sail-assisted propulsion works under gradient wind conditions in the atmospheric boundary layer, and an energy-saving device for fuel consumption. In order to study aerodynamic characteristics of a wingsail layer above sea level, transition SST turbulence model was used numerical simulation with uniform conditions. We concluded can delay stall caused by increased angle att...

Wind tunnel experiments were conducted to understand boundary layer separation control on airfoils. The objective of this research was to better implement flow control strategies with single dielectric barrier discharge (SDBD) plasma actuator designs for airfoils that exhibit both leading and trailing edge stall characteristics at realistic flight speeds and Reynolds numbers. The NASA energy ef...

Title of dissertation: DEVELOPMENT OF A TIME-ACCURATE VISCOUS LAGRANGIAN VORTEX WAKE MODEL FOR WIND TURBINE APPLICATIONS Sandeep Gupta, Doctor of Philosophy, 2006 Dissertation directed by: Minta Martin Professor J. Gordon Leishman, Department of Aerospace Engineering A second-order accurate model has been developed and validated for modeling the unsteady aerodynamics of a wind turbine. The free...