Abstract:
Defense aviation is significantly concerned with predicting the trajectory of a store
thrown from an aircraft. An ever-increasing range of stores must be carried by aircraft
due to the growing need for them to perform diverse roles in a hostile environment.
These include new, aerodynamically sophisticated stores with lifting bodies and old,
long-stockpiled missiles and bombs.
This thesis study has been divided into three parts. First, the EGLIN test case’s valida-
tion study using Chimera/Overset grid methodology is performed. Three-dimensional
Unsteady Reynolds’s Average Navier Stokes equations are solved with a Realizable k-ε
turbulence model. The position, angular orientation, and surface pressure distribution
of store results are compared with experimental data, and all the results are in good
agreement. Second, multiple stores separation from the cavity was carried out, and
the effects of passive flow control devices on the leading edge of the generic cavity were
explored. The shear layer and the flow patterns outside the cavity were observed by
the introduction of passive flow-control devices. The scenarios considered include a
no-control device (NCD), rectangular flat-plate control device (RCD), and perforated
flat-plate control device (PCD). Third, the efficacy of simulated passive flow control
techniques on store separation trajectories is compared. Considering 0.95 Mach No, in
terms of magnitude displacement, RCD stores drop 2.5m at maximum, in PCD stores
drop at 3m, while NCD stores fall only 0.3m where shear layer pushes it back inside
the cavity. The results indicate that RCD and PCD effectively suppress the pitch-
up tendency of the store during separation. It is observed that RCD faces high drag
and high-torque substantial hinge moment. When comparing the pitching and hinge
moments of PCD and RCD, it is suggested that PCD is a reasonable middle ground.
