Hypersonic aircraft & sattelite launches , a brief explanation. Dream that will come true. Very efficient!!!

1. Ranjith Rajeev
S7 M.E.
Roll no. : 38

2.  For a vehicle to be considered hypersonic, it
must travel at least at Mach 5 -- five times the
speed of sound, or about 3,800 mph.
 Hyperplane is an aircraft which travels at a
speed greater than mach 5.(Commercial
aircrafts fly at a speed of mach 0.8).
 It can be used as space launch vehicles, military
aircrafts and commercial aircrafts.

4.  ‘Streamlined body’ is the criterion for design of a
subsonic vehicle while ‘reduction of wave drag’ is
the criterion for design of a supersonic vehicle
 Excessive heating is the greatest concern in design
of hypersonic vehicles.(The nose of the reentry
vehicles attain a temperature of 11000k.)
 Stagnation point aerodynamic heating varies
inversely to the square root of the nose radius.

5.  Cooling methods are mainly classified into two
categories : 1) Active and 2) Passive cooling.
 Convective and Ablative cooling are the most
effectively used cooling systems and they re
classified as active cooling techniques.
 The convective cooling technique uses a
coolant which absorbs heat from the surface to
be cooled.

7.  In ‘ablation’ type active cooling, a layer of
ablative material is coated over the surface to
be protected. The protective layer melts and
vaporizes due to heat load absorbing large
amount of thermal energy.
 Graphite and phenolic materials are currently
popular ones for ablative materials. It is also
found that the vehicle can be cooled efficiently
by transferring coolant mass in the boundary
layer from its surface.

8.  Bluntness at the nose of the hypersonic vehicle
is necessary to alleviate the oncoming heat load
but at the same time this increases the drag.
 Increase in drag results in more fuel
requirement.
 It is observed that a marginal reduction in drag
increases the fuel efficiency greatly.

9.  The spike recasts the original bow shock into a
conical shock and induces a low pressure
recirculation region, which together forms an
aerodynamic configuration similar to that of a
slender body ahead of blunt body.
 The consequence of separation is the formation of
a low pressure and low temperature recirculation
region or separation bubble near the stagnation
region which reduces the drag.
 Separated flow reattaches at the blunt body and
the location of this reattachment point depends on
the spike length, spike configuration and
freestream conditions.

11.  Injection of a supersonic jet from the stagnation
point of a blunt body changes the pressure and
temperature distribution over the configuration of
interest.
 If the pressure of the jet is much higher than that of
the free stream pressure then the jet separates at
the edge of the orifice and moves forward.
 Separation of the jet at the edge forms a toroidal
recirculation region near the stagnation point.
Expansion of the jet from the orifice continues until
it passes through a terminal shock.

15.  It will take off from a usual runway using air
breathing engine and will reach sonic speed.
 At sonic speed the ramjets get activated,
bringing it to a hypersonic speed. During this
travel it will suck air and seperate oxygen from
that and will store it in liquid form.
 Then it will use this fuel and liquid oxygen
mixture for outer space propulsion.

17.  A 25-meter-long HyperSoar aircraft (about as
long as the wingspan of a large business jet)
could make a conventional takeoff from a
standard runway.
 Using special air-breathing, rocket-based,
combined-cycle engines, it would ascend to 40
kilometers-at the outer limit of Earth's
atmosphere.
 As it descends into denser air, the aircraft
would be pushed up by the increased
aerodynamic lift.

18.  The engines would fire briefly, propelling the
plane back into space. Outside the atmosphere,
the engines shut off and the process repeats.
 In this way, HyperSoar would skip off the top
layer of the atmosphere every two or so
minutes, like a flat rock skittering in slow
motion across the surface of a pond.
 This is a very fascinating concept developed by
Preston Carter.

21. THANK YOU..