This paper investigates the problem of active flutter suppression for a two-dimensional three degrees of freedom (3DOF) airfoil. With the influence of unsteady aerodynamic forces and parametric uncertainties, the output suboptimal control law design for a 3DOF airfoil control system is transformed into a constrained optimization problem. Then, the flutter robust suppression control law could be...

In this work we give an alterative proof of one of basic properties of zonal polynomials and generalised it for Jack polynomials

Direct numerical simulations (DNS) of the flow dynamics over a NACA 0012 airfoil at Reynolds number Re = 5× 104 at different angles of attack are presented. The dynamic of the large separation bubble, characterised by laminar boundary layer separation, transition to turbulence and flow reattachment is analysed in detail by means of instantaneous data al different locations in the suction side o...

The lag model proposed by Olsen and Coakley is incorporated into the baseline two-equation k-ω turbulence model to simulate the transonic and supersonic turbulent separated flow. The performances of the lagged k-ω turbulence model is assessed by computing two transonic airfoil flow cases, the RAE2822 Case 10 and the 18% thick double circular arc airfoil, and a separated nozzle flow. The computa...

The problem of incompressible steady flow simulation around an airfoil is discussed. For some simplest airfoils (circular, elliptical, Zhukovsky airfoils) the exact solution is known from complex analysis. It allows to compute the intensity of vortex layer which simulates the airfoil. Some modifications of the vortex element method are proposed and test computations are carried out. It’s shown ...

This paper applies an exergy-based method on the two-dimensional airfoil and various threedimensional wing planforms to investigate the impact of exergy on aerodynamic designs. Our intent here is to report our efforts to couple a numerical code with an exergy analysis, a shape shifting algorithm and an optimization code to achieve desired airfoil and wing shapes. Exergy-based optimization is pe...

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...

Following Prandtl, a viscous-inviscid interaction (VII) method is presented, where the flow field is divided into a viscous shear layer and an inviscid outer region. Their coupling is performed with the quasi-simultaneous approach, making use of an appropriately chosen interaction law. Firstly, an engineering example of transonic airfoil flow is presented, in which the interaction law is based ...

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...