A multidisciplinary research effort that combines aerodynamic modeling and gain-scheduled control design for aircraft flight at post-stall conditions is described. The aerodynamic modeling uses a decambering approach for rapid prediction of post-stall aerodynamic characteristics of multiple-wing configurations using known section data. The approach is successful in bringing to light multiple so...

Numerous experiments have been conducted on plunging Eppler 361 airfoil in a subsonic wind tunnel. The experimental tests involved measuring the surface pressure distribution over the airfoil at Re=1.5×105. The airfoil was equipped with Gurney flap(heights of 2.6, 3.3 and 5% chord) and plunged at 6cm amplitude. The unsteady aerodynamic loads were calculated from the surface pressure measurement...

Abstract The post-stall flow control using compliant flags of varying thickness and length, placed upstream a NACA0012 airfoil, was shown to be possible at an airfoil chord Reynolds number 100,000. flag wakes produced substantial increase in the stall angle maximum lift coefficient optimal cross-stream locations from wake centerline. Oscillating could generate periodic with better spanwise cohe...

The present research investigates the torsional aeroelasticity of the blade of an H-type vertical axis wind turbine subject to stall and post-stall conditions in various Reynolds regimes, which is experienced by the blade in a full revolution. In order to simulate the aerodynamics, a new model based on a combination of the Double Multi Streamtubes (DMST) model and the nonlinear multi-criteria C...

Based on phase space reconstruction and fractal dynamics in nonlinear dynamics, a method is proposed to extract and analyze the dynamics of the rotating stall in the impeller of centrifugal compressor, and some numerical examples are given to verify the results as well. First, the rotating stall of an existing low speed centrifugal compressor (LSCC) is numerically simulated, and the time series...

Health prophylaxis management practices have acquired a major role in the success of dairy herd health programs, however, little is known about the scope and level of implementation on Swiss dairy farms. The main objective of this study was therefore to provide a general overview of the most important preventive measures which are currently being used on these farms. In March 2011, an online su...

Birds routinely execute post-stall maneuvers with a speed and precision far beyond the capabilities of our best aircraft control systems. One remarkable example is a bird exploiting post-stall pressure drag in order to rapidly decelerate to land on a perch. Stall is typically associated with a loss of control authority, and it is tempting to attribute this agility of birds to the intricate morp...

A small flag attached to the surface of an airfoil near leading-edge exhibits self-excited oscillations when is set at a post-stall angle attack. The limit cycle between and freestream produce vortices periodically, resulting in remarkable increase maximum lift coefficient stall angle. There are strong similarities this passive flow control method, which relies on fluid-structure interactions, ...

active flow control has great importance in design of flying objects in general and control flaps in particular. using dielectric barrier discharge as plasma actuators over control flaps can cause a change in position of separation point or can eliminate it. this new flow control device produces a body force that causes generating a micro wall jet. the present study aims to investigate experime...