Abstract: This work aims to study and simulate the flow field around light a/c using
numerical solution based on solving Reynolds Averaged Navier-Stokes equations coupled
with K-ω SST turbulence model.
Solution strategy began by analyzing wing alone then analyzing the whole a/c configuration.
This strategy allows studying the wing flow field carefully and analyzing the vortices which
occur over the wing and capture their effective regions at critical design conditions like stall
condition. These regions were captured by plotting pressure contours and flow pathlines.
The aerodynamic behavior of this aircraft was investigated at different angles of attack and
side slip angles. The x, y and z forces and moments were calculated at flight speed of 50m/s
and at sea level conditions. Lift and drag curves for different angles of attack were plotted.
The maximum lift coefficient for this a/c was 1.67 which occurred at angle of attack 16o , the
maximum lift to drag ratio (L/D) found to be 14 which occurred at α=3o, and the zero lift drag
coefficient was 0.0342. Also the yawing moment coefficient was plotted for different side slip
angles as well as rolling moment.
The longitudinal stability derivatives with respect to angle of attack, speed variation (u), pitch
rate (q) and time rate of change of angle of attack were calculated using obtained CFD results.
Regarding lateral stability only side slip derivatives were calculated.