Prepared underQIP-CD Cell ProjectLectureLecture--2020

Jet PropulsionJet Propulsion

Ujjwal K Saha, Ph. D.Department of Mechanical Engineering

Indian Institute of Technology Guwahati

The Concorde JetThe 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:History:

•• 9 of March 1959 9 of March 1959 -- Thinking of commercial supersonic Thinking of commercial supersonic planes planes -- Great BritainGreat Britain•• 17 of August 1962 17 of August 1962 –– (Handley Page) HP(Handley Page) HP--115 tests a 115 tests a supersonic wing supersonic wing -- GreatGreat--Britain Britain

History:History:•• 31 of December 1968 31 of December 1968 –– The Soviets create the The Soviets create the TupolevTupolev TUTU--144, nicknamed 144, nicknamed ConcordskiConcordski, is the first , is the first supersonic commercial plane to fly. It flew for 38 supersonic commercial plane to fly. It flew for 38 minutes.minutes.•• 2 of March 1969 2 of March 1969 --Toulouse, Concorde 001 takes off.Toulouse, Concorde 001 takes off.•• 18 of February 197318 of February 1973-- The TUThe TU--144 were withdrawn 144 were withdrawn from any further flights with no reason given, after from any further flights with no reason given, after two of them crashed.two of them crashed.

History:History:

•• 21 of January 1976 21 of January 1976 ––First commercial flight for the First commercial flight for the concord.concord.

•• 23 of July 2000 23 of July 2000 -- British Airways discloses that cracks British Airways discloses that cracks had been found in the wings of all seven of its Concorde had been found in the wings of all seven of its Concorde jets. Air France makes a similar disclosure the following jets. Air France makes a similar disclosure the following day, having found cracks in four of its six day, having found cracks in four of its six ConcordesConcordes..

•• 25 of July 200025 of July 2000-- An Air France Concorde flying to New An Air France Concorde flying to New York crashes outside Paris shortly after takeoff, killing all York crashes outside Paris shortly after takeoff, killing all 113 people on board and four people on the ground. 113 people on board and four people on the ground.

The Concorde vs. Other Passenger JetThe Concorde vs. Other Passenger Jet

•• A Boeing 747 aircraft cruises at about 560 mph (901 A Boeing 747 aircraft cruises at about 560 mph (901 kmphkmph, or Mach 0.84) at an altitude of 35,000 ft (10,675 , 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 m). In contrast, the Concorde cruises at 1,350 mph (2,172 kmphkmph, or , or Mach 2Mach 2) at an altitude of ) at an altitude of 60,000 ft60,000 ft (18,300 m). (18,300 m). •• The Concorde is limited in setting, it can only take 100 The Concorde is limited in setting, it can only take 100 passengers while a Boeing 747 can take up to 416 passengers while a Boeing 747 can take up to 416 passengers.passengers.•• The Concorde has not video capabilities because it was The Concorde has not video capabilities because it was thought too heavy, however the Boeing 747 does have it. thought too heavy, however the Boeing 747 does have it.

Features of the Concorde that other Features of the Concorde that other aircraft do not have:aircraft do not have:

As any aircraft approaches the speed of sound (1100 ft/s, As any aircraft approaches the speed of sound (1100 ft/s, 343 m/s), the air pressure builds up in front of the aircraft, 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, forming a "wall" of air. To punch through that wall of air, planes must be streamlined. planes must be streamlined. ••Streamlined designStreamlined design

••NeedleNeedle--like fuselagelike fuselage••SweptSwept--back delta wingback delta wing••Moveable noseMoveable nose••Vertical tail designVertical tail design

••The long, narrow shape of the Concorde reduces the drag The long, narrow shape of the Concorde reduces the drag on the plane as it moves through the air. on the plane as it moves through the air.

Features of the Concorde that other Features of the Concorde that other aircraft do not have:aircraft do not have:

•• The wing of the Concorde is thin, swept back and The wing of the Concorde is thin, swept back and triangular.triangular.•• There is no space between the fuselage and the wing of the There is no space between the fuselage and the wing of the Concorde.Concorde.•• The Concorde's wing is called a The Concorde's wing is called a deltadelta--wing designwing design and and does the following: does the following:

••Reduces drag by being thin and swept back (55 degrees with the fReduces drag by being thin and swept back (55 degrees with the fuselage)uselage)••Provides sufficient Provides sufficient liflift for takeoff and landing at subsonic speeds t for takeoff and landing at subsonic speeds ••Provides stability in flight so that no horizontal stabilizers aProvides stability in flight so that no horizontal stabilizers are needed on re needed on the tail the tail

Features of the Concorde that other Features of the Concorde that other aircraft do not have:aircraft do not have:

•• The Concorde has a longer, needleThe Concorde has a longer, needle--shaped nose shaped nose compared to most commercial jets:compared to most commercial jets:

•• The nose helps penetrate the air, and can The nose helps penetrate the air, and can be tilted down upon takeoff and landing be tilted down upon takeoff and landing (13 degrees) so that the pilots can see the (13 degrees) so that the pilots can see the runway.runway.

•• Also, the Concorde's nose has a Also, the Concorde's nose has a visorvisor to to protect the windshield when flying at protect the windshield when flying at supersonic speeds. supersonic speeds.

Engines built into the wingEngines built into the wingAfterburnersAfterburners

•• The engines on the Concorde provide the The engines on the Concorde provide the thrusthrust t necessary for takeoff, cruising and landing. necessary for takeoff, cruising and landing.

•• The Concorde has four Rolls Royce/The Concorde has four Rolls Royce/SnecmaSnecmaOlympus 593 Turbo Jet engines. Olympus 593 Turbo Jet engines.

•• Each engine generates 18.7 tons (180 Each engine generates 18.7 tons (180 kNkN) of thrust. ) of thrust.

•• Together, the four engines burn 6,771 gallons Together, the four engines burn 6,771 gallons (25,629 liters) of fuel per hour.

Engine Design:Engine Design:

(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: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: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 secondsPassenger capacity: 100 Overall length: 62 meters (203 ft.)Maximum takeoff weight: 185,000 kilograms (84,000 lbs.) Engines: Four, with 17,000 kilograms thrust eachFuel 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 Features of the Concorde that other aircraft do not have:aircraft do not have:

•• The Concorde's engines are attached directly to the The Concorde's engines are attached directly to the underside of the wing without engine struts. This underside of the wing without engine struts. This design reduces air turbulence and makes for a more design reduces air turbulence and makes for a more stable engine. stable engine. •• At supersonic speeds, engine struts would be At supersonic speeds, engine struts would be overstressed and likely to break. overstressed and likely to break.

Airbus 320 : The engines are attached underneath the wing with struts

Concorde : The engines are attached directly underneath the wing without struts.

Features of the Concorde that other Features of the Concorde that other aircraft do not have:aircraft do not have:

•• The Concorde's engines use afterburners to gain The Concorde's engines use afterburners to gain additional thrust to reach supersonic speeds. additional thrust to reach supersonic speeds.

•• Afterburners mix additional fuel with the exhaust Afterburners mix additional fuel with the exhaust gases from the primary combustion chamber and gases from the primary combustion chamber and burn it to get more thrust.burn it to get more thrust.

Features of the Concorde that Features of the Concorde that other aircraft do not have:other aircraft do not have:

••Main and auxiliary fuel tanks Main and auxiliary fuel tanks •• The Concorde has The Concorde has 17 fuel tanks17 fuel tanks that that can hold a total of can hold a total of 31,569 gallons31,569 gallons(119,500 liters) of (119,500 liters) of kerosene fuel.kerosene fuel.

•• The Concorde also has three auxiliary The Concorde also has three auxiliary or or trim fuel tankstrim fuel tanks that are use to that are use to maintain center of gravity equal to center maintain center of gravity equal to center of lift.of lift.

Features of the Concorde that other Features of the Concorde that other aircraft do not have:aircraft do not have:

•• HighHigh--reflectivity Paintreflectivity Paint•• Because the Concorde moves faster than sound, the air Because the Concorde moves faster than sound, the air pressure and friction (collision with air molecules) really pressure and friction (collision with air molecules) really heat up the plane. The temperature of the aircraft's skin heat up the plane. The temperature of the aircraft's skin varies from 261 degrees Fahrenheit (127 degrees Celsius) varies from 261 degrees Fahrenheit (127 degrees Celsius) at the nose to 196 F (91 C) at the tail. at the nose to 196 F (91 C) at the tail.

•• To help reflect and radiate this heat, the Concorde has a To help reflect and radiate this heat, the Concorde has a highhigh--reflectivity white paint that is about reflectivity white paint that is about twice as twice as reflective as the white paint on other jets. reflective as the white paint on other jets.

•• To minimize the stress on the aircraft, the Concorde is To minimize the stress on the aircraft, the Concorde is made of a special aluminum alloy (AU2GN) that is made of a special aluminum alloy (AU2GN) that is lightweight and more heatlightweight and more heat--tolerant than titanium. tolerant than titanium.

Use of Trim Tanks: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: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 aircraftengine performance. FADEC has been produced for both piston engines jet enginesand , 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: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 610Description 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 heat-resistant 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 610Description 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 vaporiserintake 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 610Description 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. Monoblocsecondary nozzle with each twin nacelle manufactured fromStresskin 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.

NozzleNozzle

Nozzles of the Mk 610 (Type 28), showing one open, the other partly closed for subsonic cruise (1996)

Blade MaterialBlade Material

Blade MaterialBlade MaterialThe 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, nickel-based 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: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 So why the Concorde was not a success?a success?

•• It was not cost efficient. (Demand decrease and cost It was not cost efficient. (Demand decrease and cost increase).increase).•• It cost around $9300 to go from Europe to USA It cost around $9300 to go from Europe to USA round trip in a concord.round trip in a concord.

The Concorde's cabin A Concorde landing

Citations:Citations:

•• http://travel.howstuffworks.com/http://travel.howstuffworks.com/•• www.concordewww.concorde--jet.comjet.com•• www.cnn.comwww.cnn.com•• www.cbs.comwww.cbs.com•• http://wikipedia.org/http://wikipedia.org/•• http://www.http://www.janesjanes.com/transport/news.com/transport/news