Institutional Digital Repository (Indian Institute of Technology Kharagpu)

Das, Subhajit

Structural Damage Identification using Multi-Stage Metaheuristic Optimization Techniques

Siddiqi, Hammad

Pyrolytic Conversion of Waste Biomass towards Alternate and Sustainable Energy

Arumugaraj, Nadar Raviarun

Modelling and Analysis of Ambulance Location-Allocation Problem in Emergency Medical Services

Chakraborty, Sayantan

Fractal Dimension for Identification of Fracture Modes in Coal Measure Rocks in Uniaxial Compression and Tension

Jaiswal, Namrata

Regional Seismic Wave Attenuation Tomography in Western Tibet and Surrounding Regions

Verma, Surendra

Nonlinear Bending and Buckling Analysis of Laminated and Sandwich Curved Panels in Hygrothermal Environment

Roy, Achintya

Reliability Study of a Coherent System Equipped With Cold Standby Components

S M, Aparna

High-Performance Work Practices in Academia: Impact on Academic Output of Select Higher Education Institutes in India

Kumawat, Lokesh

Development of a Hand Tractor Powered Topper cum Digger for Onion Crop

Grandhi, Raj Kiran

Abstract of the thesis: “Enhancement of the control effectiveness of
a transverse jet in a supersonic crossflow”
Roll No: 14AE91S01 Name: Raj Kiran Grandhi
The interaction of sonic or supersonic side jet with an external supersonic cross-
flow generates a complex flow structure that has been a subject of much interest to the
aerospace community. Such flows are encountered in reaction control systems, divert
thrust motors for interceptors, secondary injection thrust vector control systems, retro
motor assisted stage separation systems and scramjet engines. This interaction signif-
icantly alters the surface pressure distribution over the vehicle and consequently the
lateral force and moment generated by operating the jet.
In this dissertation, the basic features of this jet interaction over bodies of revo-
lution are studied using computational fluid dynamics. After verifying the simulation
methodology through grid independence studies and validating the results with pub-
lished experimental data, a series of studies were carried out to quantify the effects of
several key parameters on the interaction flow field and on the effectiveness of the jet
in producing the desired control forces and moments. The preliminary studies were
followed up with more elaborate studies into the role of parent body curvature and ex-
ternal flow environment on the interaction flow field and the associated jet effectiveness.
These studies have enabled a detailed analysis of the differences in the interaction flow
structures on flat and curved parent bodies and their dependence on the flight altitude.
The insights gained from these detailed studies have led to the exploration of sev-
eral techniques for improving the jet effectiveness on curved parent bodies. These tech-
niques include changes to the location of the injected jet, employing jets in tandem and
injecting pilot jets ahead of the primary jet. Injection of a control jet from the aft regions
of the vehicle resulted in an increase in the effectiveness of the jet as compared to injec-
tion from a forward location. Tandem injection of multiple jets caused an amplification
of jet thrust in the near-field of the jet. These gains in the near field were partially offset
by unfavourable interaction further downstream of the injections. Injecting small pilot
jets ahead of the main jet resulted in an enhancement of jet effectiveness by 10%–12%
which persisted significantly downstream of the injection.
Finally, the transient behaviour of the jet interaction flowfield over the vehicle due
to a reaction control pulse and the overall effect of the initial and tail-off transients on
the control effectiveness are studied using unsteady simulations.


Enhancement of the Control Effectiveness of a Transverse Jet in a Supersonic Crossflow

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