Abstract:
Transonic flow around supercritical airfoil involves shock induced oscillation
at certain free stream Mach number and angle of attack due to the interaction of shock
wave with airfoil boundary layer. This interaction consequences fluctuating lift and
drag coefficient, aero acoustic noise and vibration, intense drag rise, high cycle
fatigue failure (HCF), buffeting and so on. Moreover, the unsteady pressure
fluctuations generated by the shock motions are highly undesirable from structural
integrity and aircraft maneuverability point of view. The aerodynamic characteristics
of the present problem have been solved by numerical computation. A commercial
finite volume CFD package has been used for this computation. The computational
domain has been discretized into a structured mesh by using a commercial
preprocessing tool. The transonic flow around a supercritical airfoil is governed by
the unsteady compressible Reynolds-averaged Navier-Stokes equation together with
the energy equation. Two additional equations of k-ω SST turbulence model have
been included to model the turbulence in the flow field. The results obtained from the
numerical computation have been validated with the experimental results.
Maintaining same flow parameters computational analysis has been done at free
stream Mach number 0.77 and angle of attack from 2° to 7°. Mach contour, lift and
drag coefficient, pressure coefficient and pressure history at different points over the
airfoil has been captured and analyzed. To suppress the self-excited shock oscillation
effectiveness of bump based passive control technique around the airfoil in transonic
interval flows has been numerically analyzed and found its effectiveness.
