In this slide discuss about a enhancement of combustion in scram jet engine.and use a vortex generator to get a maximum efficiency from the jet

1. Presented by,
Vignesh.V
Numerical simulation of mixing enhancement in scramjet
using micro vortex generator

2. Objectives :
 To improve the efficiency of supersonic combustion apart from
cavity flows to micro vortex generator.
 By comparing supersonic combustor with cavity flow and micro
vortex generator , it is evident that supersonic combustor with micro
vortex generator has high combustion efficiency.
 Modified combustor with micro vortex generators is found to
improve the fuel air mixing and performance of combustor.

3. Introduction :
Development of an efficient hypersonic air breathing
propulsion system for civil and military applications has driven
the development of scramjet engine.
Researchers face a big challenges in respect of proper mixing of fuel
and air ignition and combustion inside the combustor.
 Ignition and flame holding are two other important factors that
have to be addressed in the design of an injection system
.

4. History of scram jet :
During world war-II, a tremendous amount of time & effort were put into
reassembly high speed jet and rocket powered aircraft.
The first successful flight test of a scramjet was performed by Russia
in 1991.
In 2010, NASA successfully flew the x-51 wave rider by using a scramjet
engine to reach mach 5.

5. Scramjet engine :
Scram jet is a supersonic combusting ramjet is a variant of a ram jet
Engine.
The airflow in a scramjet is supersonic throughout the entire region.
this allows the scramjet to operate efficiently at extremely high speeds.

6. Combustion in scram jet engine :
The complex phenomenon of supersonic combustion involves turbulent
mixing, shock interaction and heat release in supersonic flow.
The flow field within the combustor of scramjet engine is very complex
and poses a considerable challenge in design and
development of a supersonic combustor with an optimized geometry
The processes governing supersonic mixing and combustion as
well as the factors , which affects the losses within the combustor

7. Vortex generators :
Vortex generators are typically rectangular or triangular about as tall as
the local boundary layer
VG are positioned obliquely in order to create a tip vortex which draws
energetic rapidly moving outside air into the slow moving boundary
layer in contact with the surface.
A turbulent boundary layer is less likely to separate then a laminar one,
and is therefore describe to ensure effectiveness of trailing edge control
surfaces.

8. Model details :
Length of the isolator: 70mm
Length of the 1st staged combustor: 88mm
Length of the 2nd staged combustor: 128mm
Length of the 3rd staged combustor: 58mm

9. I . Cavity Flame Holder :
Length of the cavity flame holder: 13.76mm

10. II. Micro vortex generator :
Length of MVG : 13.75mm
Height of the MVG : 1mm
Length of the three staged combustor is same . The cavity flame holder
is only replaced a MICRO VORTEX GENERTOR.

11. Computational details :
The grids for the geometries are generated by the commercial software
GAMBIT
The grid adaptation check has been done for both models and mesh
with 60,100 and 55,100 cells has been employed in cavity based and
vortex generator based models respectively.
The flow is considered to be in steady state
 The gas is compressible, obeying the ideal gas laws

12. CONCLUSION :
Comparison of the static pressure distribution between cavity based
and vortex based domain.
 Vortex generator show that mixing can be enhanced in
supersonic flow combustions.
There are obvious pressure rises on the top and bottom walls of the
scramjet combustor because of the impingement of the
reflected shock wave or the expansion wave on the walls.
 This illustrates that there exists the complex shock wave/shock wave
interaction and the separation due to the interaction of the boundary
layer and the oblique shock wave which also enhances the mixing
of fuel with the air stream.

13. THANK YOU