Two-dimensional direct numerical simulation of the flow over a NACA0018 airfoil with a cavity is presented. The lowReynolds number simulations are validated bymeans of flow visualizations carried out in awater channel. From the simulations, it follows that there are twomain regimes of flow inside the cavity. Depending on the angle of attack, the first or the second shear-layer mode (Rossiter to...

This paper concerns a numerical study of employing an adaptive trailing edge flap to control the lift of an airfoil subject to unsteady inflow conditions. The periodically varying inflow is generated by two oscillating airfoils, which are located upstream of the controlled airfoil. To establish the control system, a standard PID controller is implemented in a finite volume based incompressible ...

This paper presents an experimental study of the effect of trailing edge serrations on airfoil instability noise. Detailed aeroacoustic measurements are presented of the noise radiated by an NACA-0012 airfoil with trailing edge serrations in a low to moderate speed flow under acoustical free field conditions. The existence of a separated boundary layer near the trailing edge of the airfoil at a...

A new optimization approach for robust design, design for multi-objective six sigma (DFMOSS) has been developed and applied to robust aerodynamic airfoil design for Mars exploratory airplane. The present robust aerodynamic airfoil design optimization using DFMOSS successfully showed the trade-off information between maximization and robustness improvement in aerodynamic performance by a single ...

The accelerated growth in aircraft industries desire effectual schemes, programs, innovative designs of advanced systems and facilities to accomplish the augmenting need for home-free air transportation. In this paper, a contemporary conceptual design of a cambered airfoil has been proposed in order to providing augmented effective lift force relative to the airplane, and to eliminating drawbac...

The present study comprises steady state, two-dimensional computational investigations performed on NACA 0012 airfoil to analyze the effect of Gurney flap (GF) on airfoil aerodynamics using k-ε RNG turbulence model of FLUENT. Airfoil with GF is analyzed for six different heights from 0.5% to 4% of the chord length, seven positions from 0% to 20% of the chord length from the trailing edge, and s...

L OW-REYNOLDS-NUMBER airfoil aerodynamics is important for bothmilitary and civilian applications. The applications include propellers, sailplanes, ultralight man-carrying/man-powered aircraft, high-altitude vehicles, wind turbines, unmanned aerial vehicles (UAVs), and micro air vehicles (MAVs). For the applications just listed, the combination of small length scale and low flight velocities re...

The Humpback whale tubercles have been studied for more than a decade. Tubercle Leading Edge (TLE) effectively reduces the separation bubble size and helps in delaying stall. They are very effective in case of low Reynolds number flows. The current Computational Fluid Dynamics (CFD) study is on NACA 4415 airfoil, at a Reynolds number 120,000. Two TLE shapes are tested on NACA 4415 airfoil. The ...

The present paper investigates the case of an airfoil placed in a turbulent jet. The Reynolds number based on the chord length is equal to 36,000 and the Mach number to 0.04. The unsteady, threedimensional incompressible flow around the airfoil is first computed with the LES module of the commercial solver FLUENT. An innovative procedure is then proposed to compute from the CFD computation, the...

Broadband noise produced by the trailing-edge of a controlled diffusion (CD) airfoil is directly simulated using a Lattice-Boltzmann method (PowerFlow) which resolves both the aerodynamic and acoustic field around the airfoil. A proper DNS resolution is achieved in the vicinity of the airfoil for quasi-2D slice of the mock-up. Two numerical setups of the anechoic open-jet facility where both ae...