4 research outputs found
Thin Film Rupture from the Atomic Scale
The retraction of thin films, as described by the Taylor-Culick (TC) theory,
is subject to widespread debate, particularly for films at the nanoscale. We
use non-equilibrium molecular dynamics simulations to explore the validity of
the assumptions used in continuum models, by tracking the evolution of holes in
a film. By deriving a new mathematical form for the surface shape and
considering a locally varying surface tension at the front of the retracting
film, we reconcile the original theory with our simulation data to recover a
corrected TC speed valid at the nanoscale
Control of Transonic Shock Wave Oscillation over a Supercritical Airfoil
In the present study, a numerical investigation is carried out on the aerodynamic performance of a
supercritical airfoil RAE 2822. Transonic flow fields are considered where self-excited shock wave
oscillation prevails. To control the shock oscillation, a passive technique in the form of an open
rectangular cavity is introduced on the upper surface of the airfoil where the shock wave oscillates.
Reynolds Averaged Navier-Stokes (RANS) equations have been used to predict the aerodynamic
behavior of the baseline airfoil and airfoil with cavity at Mach number of 0.729 and at angle of attack
of 5Ëš. The aerodynamic characteristics of the baseline airfoil are well validated with the
available experimental data. It is observed that the introduction of a cavity around the airfoil upper
surface can completely stop the self-excited shock wave oscillation and successively improve
the aerodynamic characteristics