Showing papers in "Tsagi Science Journal in 2014"

Simulation of periodic vortical structures in the airfoil wake

Abstract: Parametrical calculations of an unsteady flow around a NACA 0012 airfoil at a fixed Reynolds number of 40,000 are performed using several multi-block overlapping grids of different scales and densities, which cover settlement areas of various extents, including the near and far wakes. The solutions found by Menter’s shear stress transport model, the Spalart–Allmaras vortex viscosity transport model, and the method of vortical domains, are compared with available estimated and experimental data. Verification of the two-dimensional model is performed by comparison of the numerical predictions for a cross flow over a thick plate with Igarashi’s experimental data.

On the possibility of laminar flow control on a swept wing by means of plasma actuators

Abstract: Theoretical assessment of the possibility of laminar §ow control (LFC) on a swept wing owing to volumetric force and heat impact of plasma actuators is presented. The proposed approach includes numerical modeling of dielectric barrier discharge (DBD) actuators, calculation of inviscid §ow over an in¦nite span swept wing, calculation of compressible boundary layer spatially modulated in spanwise direction, and numerical solution of linear stability problem for stationary modes of cross-§ow-type disturbances. Calculations have been performed for one set of geometrical and physical parameters describing plasma actuators to estimate qualitative features of volumetric force and heat input distributions. Inviscid §ow and boundary layer calculations were executed at free stream parameters corresponding to typical cruise §ight conditions. Estimation of volumetric force impact necessary for noticeable in§uence on cross-§owtype instability is obtained.