Thin airfoilIn this section we present the numerical results of AeroFoam
solver for a 2D aerodynamic test problem, such as the
inviscid compressible unsteady flow around a thin airfoil. Problem definition Domain:
 Internal very thin (t/c = 1/100) airfoil subdomain with chord c = 1 m
 External circular subdomain with radius Roo = 25 m >> c
 Material:
 Polytropic Ideal Gas (PIG)
 Specific heat ratio gamma = 1.4
 Gas thermodynamic constant R = 287.05 J/kgK
 Initial conditions:
 Thermodynamic pressure Poo = 101325 Pa
 Temperature Too = 288.15 K
 Mach number Moo = 0.5  0.7  1.0  1.2
 Angle of attack alpha = 1 deg
 Boundary conditions:
 Slip boundary conditions on internal subdomain
 Riemann boundary conditions on external subdomain
Figure: Problem definition.
Space and time discretization Space discretization:
 Mesh created with Gmsh
 # of triangular cells Nv = 6498
 # of nodes Nn = 6740
 Time discretization:
 Total simulation time endTime = 0.05 s
 Timestep deltaT = 5e6  4e6  2.5e6  2e6 s
 Maximum Courant number maxCo = 1.95
Figure: Computational grid. Numerical results Comparison with exact solution of small disturbances theory
 Single iteration CPUtime = 0.045 s on AMD64 3500+ desktop PC with AMD Athlon 64 2.2 GHz CPU, 1 Gbyte RAM, 512 Kbyte L2 cache
Figure: Time history of the lift coefficient slope CL/alpha. Download ThinAirfoil.tar.gz test problem folder. Uncompress this archive in the OpenFOAM work folder and execute AeroFoam . ThinAirfoil_7k_M050_a1 from terminal to start the simulation. Download.
