Prepared under
QIP-CD Cell Project
Lecture-20
Jet Propulsion
Ujjwal K Saha, Ph. D.
Department of Mechanical Engineering
Indian Institute of Technology Guwahati
The Concorde Jet
The Concorde is the only passenger
plane that flies faster than the speed
of sound, and can fly from New York
to London in less than 4 hours!
History:
9 of March 1959 - Thinking of commercial supersonic
planes - Great Britain
• 17 of August 1962 – (Handley Page) HP-115 tests a
supersonic wing - Great-Britain
•
History:
31 of December 1968 – The Soviets create the
Tupolev TU-144, nicknamed Concordski, is the first
supersonic commercial plane to fly. It flew for 38
minutes.
• 2 of March 1969 -Toulouse, Concorde 001 takes off.
• 18 of February 1973- The TU-144 were withdrawn
from any further flights with no reason given, after
two of them crashed.
•
History:
21 of January 1976 –First commercial flight for the
concord.
•
23 of July 2000 - British Airways discloses that cracks
had been found in the wings of all seven of its Concorde
jets. Air France makes a similar disclosure the following
day, having found cracks in four of its six Concordes.
•
25 of July 2000- An Air France Concorde flying to New
York crashes outside Paris shortly after takeoff, killing all
113 people on board and four people on the ground.
•
The Concorde vs. Other Passenger Jet
A Boeing 747 aircraft cruises at about 560 mph (901
kmph, or Mach 0.84) at an altitude of 35,000 ft (10,675
m). In contrast, the Concorde cruises at 1,350 mph (2,172
kmph, or Mach 2) at an altitude of 60,000 ft (18,300 m).
• The Concorde is limited in setting, it can only take 100
passengers while a Boeing 747 can take up to 416
passengers.
• The Concorde has not video capabilities because it was
thought too heavy, however the Boeing 747 does have it.
•
Features of the Concorde that other
aircraft do not have:
As any aircraft approaches the speed of sound (1100 ft/s,
343 m/s), the air pressure builds up in front of the aircraft,
forming a "wall" of air. To punch through that wall of air,
planes must be streamlined.
•Streamlined design
•Needle-like fuselage
•Swept-back delta wing
•Moveable nose
•Vertical tail design
•The long, narrow shape of the Concorde reduces the drag
on the plane as it moves through the air.
Features of the Concorde that other
aircraft do not have:
The wing of the Concorde is thin, swept back and
triangular.
• There is no space between the fuselage and the wing of the
Concorde.
• The Concorde's wing is called a delta-wing design and
does the following:
•
•Reduces
drag by being thin and swept back (55 degrees with the fuselage)
•Provides sufficient lift for takeoff and landing at subsonic speeds
•Provides stability in flight so that no horizontal stabilizers are needed on
the tail
Features of the Concorde that other
aircraft do not have:
The Concorde has a longer, needle-shaped nose
compared to most commercial jets:
•
The nose helps penetrate the air, and can
be tilted down upon takeoff and landing
(13 degrees) so that the pilots can see the
runway.
•
Also, the Concorde's nose has a visor to
protect the windshield when flying at
supersonic speeds.
•
Engine Design:
‰
‰
Engines built into the wing
Afterburners
The engines on the Concorde provide the thrust
necessary for takeoff, cruising and landing.
•
The Concorde has four Rolls Royce/Snecma
Olympus 593 Turbo Jet engines.
•
•
Each engine generates 18.7 tons (180 kN) of thrust.
Together, the four engines burn 6,771 gallons
(25,629 liters) of fuel per hour.
•
Air intake system
The engine air intake system is one of the most remarkable
pieces of equipment in the Concorde, and its efficiency is
of critical importance to the overall performance of the
aircraft. Taking in air at speeds up to Mach 2.2, the intake
has to deliver it in an even flow to the face of the engine at
a speed of Mach 0.5. So, at supersonic cruise, there is a
four-fold deceleration of the intake air from 1,350 mph to
about 350 mph in the length of the intake, a distance of 11
ft. Further, the mass air flow has to be precisely adjusted
to the requirements of the engines which vary
considerably over the speed range.
Specifications:
Type
BAC/Aerospatiale Concorde
Overall Length
62.10 m
Wing Span
25.55 m
Power plants
4 Rolls-Royce/Snecma Olympus
593 Mk910 with afterburners
Max Speed
2.04 Mach 2,179 km/h
Max range
6,582 km
Ceiling
18,290 km 55,424 ft
Other Data:
Takeoff speed: 360 km/h (223 mph)
Landing speed: 300 km/h (186 mph)
Runway length required for takeoff: 3,590 meters (11778.2 ft.)
Acceleration on takeoff: zero to 360 km/h in 20 seconds
Passenger capacity: 100
Overall length: 62 meters (203 ft.)
Maximum takeoff weight: 185,000 kilograms (84,000 lbs.)
Engines: Four, with 17,000 kilograms thrust each
Fuel capacity: 94,800 kilograms
Range: 6,545 kilometers (4,058 miles)
Flight time: New York-Paris: three hours 35 minutes
Features of the Concorde that other
aircraft do not have:
The Concorde's engines are attached directly to the
underside of the wing without engine struts. This
design reduces air turbulence and makes for a more
stable engine.
• At supersonic speeds, engine struts would be
overstressed and likely to break.
•
Concorde : The engines are attached
directly underneath the wing without struts.
Airbus 320 : The engines are attached
underneath the wing with struts
Features of the Concorde that other
aircraft do not have:
The Concorde's engines use afterburners to gain
additional thrust to reach supersonic speeds.
•
Afterburners mix additional fuel with the exhaust
gases from the primary combustion chamber and
burn it to get more thrust.
•
Features of the Concorde that
other aircraft do not have:
•Main and auxiliary fuel tanks
The Concorde has 17 fuel tanks that
can hold a total of 31,569 gallons
(119,500 liters) of kerosene fuel.
•
The Concorde also has three auxiliary
or trim fuel tanks that are use to
maintain center of gravity equal to center
of lift.
•
Features of the Concorde that other
aircraft do not have:
•
High-reflectivity Paint
Because the Concorde moves faster than sound, the air
pressure and friction (collision with air molecules) really
heat up the plane. The temperature of the aircraft's skin
varies from 261 degrees Fahrenheit (127 degrees Celsius)
at the nose to 196 F (91 C) at the tail.
•
To help reflect and radiate this heat, the Concorde has a
high-reflectivity white paint that is about twice as
reflective as the white paint on other jets.
•
To minimize the stress on the aircraft, the Concorde is
made of a special aluminum alloy (AU2GN) that is
lightweight and more heat-tolerant than titanium.
•
Use of Trim Tanks:
As the Concorde reaches supersonic speeds, its
aerodynamic center of lift shifts backward.
• This shift drives the nose of the aircraft downward.
• To maintain balance, fuel is pumped backward into the
trim tanks.
• The redistribution of fuel balances the aircraft by
making its center of gravity match the center of lift.
• When the plane slows down, the center of lift shifts
forward.
• Fuel is then pumped forward into the trim tanks to
compensate.
•
So, unlike other jets, the Concorde uses fuel not only
for the engines, but also for aerodynamic stability.
Use of FADEC:
FADEC is the acronym for Full Authority Digital Engine
Control. It is a system consisting of a digital computer and
its related accessories which control all aspects of aircraft
engine performance. FADEC has been produced for both
piston engines and jet engines, their primary difference
due to the different ways of controlling the engines.
The airplane's thrust lever sends electrical signals (pilot's
command, may also be the auto-throttle) to FADEC. The
FADEC digitally calculates and precisely control the fuel
flow rate to the engines giving precise thrust. The inputs
comes from various aircraft and engine sensors. Unlike
older hydro-mechanical fuel controllers, the settings stay
in place and do not drift.
FADEC:
FADEC today is employed by almost all current generation jet
engines and increasingly in newer piston engines, on fixed-wing
aircraft and helicopters. The summary of advantages are as below:
• better fuel efficiency
• automatic engine protection against out-of-tolerance operations
• safer as the multiple channel FADEC computer provides
redundancy in case of failure
• care-free engine handling, with guaranteed thrust settings
• ability to use single engine type for wide thrust requirements by
just reprogramming FADEC
• provides semi-automatic engine starting
• provides engine long-term health monitor
Description refers to the production engine, the 593 Mk 610
TYPE:
Axial-flow,
two-spool
turbojet
with
partial
afterburning.
INTAKE: Fabricated titanium casing, with zero-swirl five-spoke support for the
front LP compressor bearing. In the Concorde, the engine is installed
downstream of an intake duct incorporating auxiliary intake and exit door
systems and a throat of variable profile and cross-section.
LP COMPRESSOR: Seven-stage axial-flow type, with all blading and discs
manufactured from titanium. Single-piece casing machined from a stainless steel
forging, electrochemically machined.
HP COMPRESSOR: Seven-stage axial-flow compressor. The first three stages
of blades are made from titanium alloy. Remaining stages are made from a heatresistant material due to very high compressor delivery temperatures during
supersonic flight. Steel single-piece casing. Mass flow 186 kg (410 lb)/s. Overall
pressure ratio 15.5:1.
Description refers to the production engine, the 593 Mk 610
INTERMEDIATE CASE: Titanium casing, with vanes supporting LP and HP
thrust bearings. Drives for engine-mounted aircraft and engine auxiliary drive
gearboxes are taken out through the intermediate casing.
COMBUSTION CHAMBER: Annular cantilever mounted from the rear.
Fabricated as single unit from nickel alloy, with all joints butt-welded to ensure
reliability. Electrochemically machined. The combustion system burner
manifold and the main support trunnions are located around the delivery
casing. Total of 16 vaporising burners, each with twin outlets, bolted directly
into chamber head. Fuel injectors are simple pipes which enter each vaporiser
intake with no physical contact. Combustion leaves virtually no visible smoke in
the propulsive jet.
HP TURBINE: Single-stage turbine, with cooled stator and rotor blading.
LP TURBINE: Single-stage, with cooled rotor blades. LP drive shaft coaxial
with HP shaft.
Description refers to the production engine, the 593 Mk 610
JET PIPE: Comprises a straight jet pipe and a pneumatically
actuated variable primary convergent nozzle which permits
maximum LP-spool speed and turbine-entry temperature to be
achieved simultaneously over a wide range of compressor-inlet
temperatures. Single-ring afterburner with programmed fuel
control as a function of main-engine fuel flow. Monobloc
secondary nozzle with each twin nacelle manufactured from
Stresskin panels. Each power plant terminates in a pair of
`eyelids' which form a variable-area secondary divergent nozzle
and thrust reverser. The eyelid position is programmed to
maintain optimum power plant efficiency through all the flight
regimes: take-off, subsonic cruise and supersonic cruise. When
completely closed they act as thrust reversers.
Nozzle
Nozzles of the Mk 610 (Type 28), showing
one open, the other partly closed for
subsonic cruise (1996)
Blade Material
Blade Material
The Low Pressure (LP) and the first few stages of the
High Pressure (HP) compressor rotors and stators and
the inlet spkes are made form titanium. This material
combines lightness with the strength needed to handle
foreign objects such as ice, birds, etc. To deal with the
high delivery temperatures in supersonic cruise, nickelbased alloys are used for the blades of the final four HP
compressor rotors and stators. These alloys are also
used for HP and LP turbine rotor and stator blades.
Waspalloy is a high nickel content alloy with excellent
tensile strength and creep properties. It is used for the
final four HP compressor discs, the combustion chamber
inner and outer casings, both turbine discs, and the
exhaust outer annulus casing. The casings for the
compressor are made from a one-piece steel
construction.
Aircraft Histories:
Only 20 Concordes were built, six for development and 14
for commercial service.
These were:
• two prototypes
• two pre-production aircraft
• 16 production aircraft
• The first two of these did not enter
commercial service
• Of the 14 which flew commercially, 12 were
still in service in April 2003.
So why the Concorde was not
a success?
It was not cost efficient. (Demand decrease and cost
increase).
• It cost around $9300 to go from Europe to USA
round trip in a concord.
•
The Concorde's cabin
A Concorde landing
Citations:
http://travel.howstuffworks.com/
• www.concorde-jet.com
• www.cnn.com
• www.cbs.com
• http://wikipedia.org/
• http://www.janes.com/transport/news
•