Low Reynolds number response of a symmetric airfoil to viscous vortical gusts
收藏资源简介：
The response of a NACA0012 airfoil impacted by viscous vortical gusts at low Reynolds numbers is investigated performing Direct Numerical Simulations of the two-dimensional incompressible flow. This database contains the time history of the aerodynamic force coefficients of the airfoil during the interaction with the vortical gust. The airfoil, set at a fixed angle of attack alpha, is impacted by Taylor/Lamb-Oseen vortical gust, which are characterized by a diameter <em>D</em>, a intensity <em>v<sub>0m</sub></em>, and a vertical separation <em>h</em>. Direct Numerical Simulations are run for a range of values for the angle of attack, the size and intensity of the vortical gust, and the vertical separations. All simulations are run at a fixed Reynolds number Re=1000, based on the airfoil chord <em>c</em> and the free-stream velocity <em>U<sub>∞</sub></em>. More details on the database and the corresponding simulations can be found in Martínez-Muriel & Flores (2020), Analysis of vortical gust impact on airfoils at low Reynolds number, J. Fluids and Struct, 99. <strong>Contents</strong><br> The database consist on a single ASCII file for each case. After a short, self-explanatory header, each file has 7 columns with the following data: time, <em>t U<sub>∞</sub>/c</em> cl: lift coefficient, <em>c<sub>l</sub></em> cd: drag coefficient, <em>c<sub>d</sub></em> cm: coefficient of moments with respect to c/4, <em>c<sub>m</sub></em> dcl: perturbation of <em>c<sub>l</sub></em> with respect to steady state value, ∆<em>c<sub>l</sub></em> dcd: perturbation of <em>c<sub>d</sub></em> with respect to steady state value, ∆<em>c<sub>d</sub></em> dcm: perturbation of <em>c<sub>m</sub></em> with respect to steady state value, ∆<em>c<sub>m</sub></em> Reference time (t=0) is taken as the time at which the center of the vortical gust reaches the position of the leading edge of the airfoil (if advected at a velocity <em>U<sub>∞</sub></em>). <br> <br> <strong>Nomenclature </strong><br> The names of the files will follow the acronym t_AaYyDdVv.txt, where the lowecase letters are placeholders for: t Type of vortical gust T: Taylor, LO: Lamb-Oseen a Angle of attack <em> α</em> = [+8,0,-8] deg y Initial vertical position of the centre of the vortex <em> h/c </em>= [0,0.5,1] d Diameter of the core of the vortex <em> D/c </em>= [0.5,1,2] v Circumferential velocity <em> v<sub>0m</sub></em>/<em>U<sub>∞</sub></em> = [0.1,0.3,1]
