A pressure based implicit procedure to solve the Euler and Navier-Stokes equation is developed to predict transonic viscous and inviscid flows around the pitching and heaving airfoils with a high reslution scheme. In this process, nonorthogonal and non moving mesh with collocated finite volume formulation are used. In order to simulate pitching or heaving airfoil, oscillation of flow boundary c...

The main objective of the “INNWIND.EU” project is to investigate and demonstrate innovative designs for 10-20MW offshore wind turbines and their key components, such as lightweight rotors. In this context, the present paper describes the development of two new airfoils for the blade root region. From the structural point of view, the root is the region in charge of transmitting all the loads of...

Small unmanned aerial vehicles (SUAVs) have recently attracted considerable research and development interest owing to their small size, portability, and limited operational risk. In SUAVs, the Reynolds number Re is typically very low because they are small and fly at low speeds. The Reynolds number strongly influences the airfoil performance, and at Re = 10, the lift-drag (L/D) ratio decreases...

This paper presents an integrated method for designing airfoil families of large wind turbine blades. For a given rotor diameter and tip speed ratio, the optimal airfoils are designed based on the local speed ratios. To achieve high power performance at low cost, the airfoils are designed with an objective of high Cp and small chord length. When the airfoils are obtained, the optimum flow angle...

Adaptive closed-loop control is used to optimize the lift-to-drag ratio of post-stall separated flow over a NACA 0025 airfoil using multiple amplitudemodulated (AM) or burst-modulated (BM), zero-net-mass-flux (ZNMF) actuators that cover the central 33% span of the airfoil. A simplex optimization approach uses the lift and drag measured by a strain-gauge balance for feedback and searches for the...

Overlap Level of Regular Dual graph (no. elements) coarse grid coarsening coarsening 0 None 56 56 0 4 21 22 0 3 15 12 1 None 16 16 1 4 10 10 1 3 7 7 2 None 14 14 2 4 8 8 2 3 5 5 Table 2 Multigrid iterations for the Airfoil mesh Regular coarsening Dual graph coarsening MG Levels Nodes Dir. B. Overlapping schwarz methods on unstructured meshes using non-matching coarse grids. Domain decomposition...

This paper presents the development and application of an adjoint-based optimization method to designing airfoils with the objective of alleviating dynamic stall effects in helicopter rotor blades. The unsteady flow problem is simulated using the NSU2D code, which is a two-dimensional unsteady, viscous, turbulent Reynolds averaged Navier-Stokes (RANS) finite-volume solver. The corresponding adj...

Supersonic channel airfoil design techniques have been shown to significantly reduce drag in high-speed flows over diamond shaped airfoils by Ruffin and colleagues. The effect of applying these techniques to a NACA 66-206 airfoil is presented. The design domain entails channel heights of 8-16.6% thickness-to-chord and speeds from Mach 1.5-3.0. Numerical simulations show an increase in the lift-...

A new two-dimensional approximate Riemann solver has been developed that obtains fluxes on grid faces via wave decomposition. By utilizing information propagating in the velocity-difference directions rather than in the grid-normal directions, this flux function more appropriately interprets and hence more sharply resolves shock and shear waves when they lie oblique to the grid. The model uses ...

Small wind turbines are gaining popularity due to their ability to meet community or domestic needs in isolated areas with relatively easier installation and lower cost than large wind turbines. This study looks at optimizing airfoils for use in small horizontal axis wind turbines. The optimization looks to maximize the lift coefficient (Cl ) while minimizing or fixing the drag coefficient (Cd)...