THE HISTORY OF THE JET ENGINE

JET ENGINES CAN BE DATED BACK TO THE INVENTION OF THE AEOLIPILE IN 150 B.C. THE AEOLIPILE, ALSO KNOWN AS A HERO'S MACHINE, USED STEAM POWER DIRECTED THROUGH TWO NOZZLES, CAUSING A SPHERE TO SPIN RAPIDLY ON ITS AXIS. THE AEOLIPILE WAS NOT USED FOR SUPPLYING MECHANICAL POWER AND THE POTENTIAL PRACTICAL APPLICATIONS WERE NEVER RECOGNIZED; IT WAS CONSIDERED TO BEONLY A CURIOSITY.
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ARCHYTAS, THE FOUNDER OF MATHEMATICAL MECHANICS, DESIGNED AND BUILT THE FIRST ARTIFICIAL, SELF-PROPELLED FLYING DEVICE. IT WAS A BIRD-SHAPED MODEL, PROPELLED BY A JET OF WHAT WAS PROBABLY STEAM.
OTTOMAN LAGARI HASAN CELEBI TOOK OFF IN 1633 WITH A CONE-SHAPED ROCKET, GLIDED WITH WINGS INTO A SUCCESSFUL LANDING, WINNING A POSITION IN THE OTTOMAN ARMY.THE PROBLEM WITH THIS, HOWEVER, IS THAT ROCKETS ARE TOO INEFFICIENT AT LOW SPEEDS TO BE USEFUL FOR GENERAL AVIATION.
RUSSIAN ENGINEER V.V. KARAVODIN PATENTED THE FIRST WORKING PULSEJET IN 1906.THE FIRST WORKING MODEL WAS COMPLETED IN 1907.
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GEORGES MARCONNET PATENTED HIS VALVELESS PULSEJET ENGINE IN 1908 WHILE RAMANCASANOVA CONSTRUCTED A PULSEJET IN 1913, BUT ONLY PATENTED THE IDEA IN 1917.
ROBERT GODDARD INVENTED A PULSEJET IN 1931, DEMONSTRATING IT ON A JET-PROPELLED BICYCLE. A MORE EFFICIENT DESIGN BASED ON THE MODIFICATION OF THE INTAKE VALVES WAS PIONEERED BY PAUL SCHMIDT. THIS EARNED HIM GOVERNMENT SUPPORT FROM THE GERMAN AIR MINISTRY IN 1933.

HYBRID ENGINES WERE EARLY ATTEMPTS AT AIR BREAKING JET ENGINES IN WHICH AN EXTERNAL POWER SOURCE FIRST COMPRESSED AIR, MIXED WITH FUEL AND BURNED FOR JET THRUST. IN ONE SUCH A SYSTEM CALLED A THERMOJET WHICH WAS DESIGNED BY THE ITALIAN ENGINEER AND ONE OF THE PIONEERS OF THE JET ENGINE, SECONDO COMPINI, BUT MORE COMMONLY, MOTORJET, THE AIR WAS COMPRESSED BY A FAN DRIVEN BY A CONVENTIONAL PISTON ENGINE.

EXAMPLES OF THIS WERE THE CAPRONI CAMPINI N.1 AND THE JAPANESE TSU-11 WHICH WAS INVENTED TO POWER OHKA KAMIKAZE PLANES IN WWII.
NONE OF THEM WERE SUCCESSFUL, THE C.C.2 ENDED UP BEING SLOWER THAN THE SAME DESIGN WITH A TRADITIONAL ENGINE AND PROPELLER COMBINATION.
FRENCH AEROSPACE ENGINEER, RENE LARIN, PATENTED A DESIGN FOR THE WORLD'S FIRST RAMJET IN 1913. THE CONCEPT REMAINED THEORETICAL AS IT WAS NOT POSSIBLE TO DEVELOP A WORKING PROTOTYPE. NO EXISTING AIRPLANE COULD ACHIEVE SUFFICIENT SPEED FOR OPERATION.
IN THE 1930S A REALIZATION CAME ABOUT THAT THE MAXIMUM PERFORMANCE OF PISTON ENGINES WAS LIMITED. THE PROPULSIVE ENERGY DECLINED AS THE BLADE TIPS APPROACHED THE SPEED OF SOUND. FOR ENGINE PERFORMANCE TO INCREASE BEYOND THIS BARRIER, A WAY NEEDED TO BE FOUND TO IMPROVE THE DESIGN OF THE PISTON ENGINE.

THE KEY TO A PRACTICAL JET ENGINE WAS THE GAS TURBINE THAT EXTRACTED ENERGY FROM THE ENGINE TO DRIVE THE COMPRESSOR. IN 1971 THE PATENT FOR A STATIONARY TURBINE WAS GRANTED TO JOHN BARBER. NORWEGIAN ENGINEER ÆGIDIUS ELLING BUILT THE FIRST GAS TURBINE TO SUCCESSFULLY RUN SELF-SUSTAININGLY IN 1903. THESE ENGINES NEVER GOT MANUFACTURED AS LIMITATIONS IN DESIGN AND PRACTICAL ENGINEERING AND METALLURGY PREVENTED IT.

IN 1915 ALBERT FONO CAME UP WITH A SOLUTION TO INCREASE THE RANGE OF ARTILLERY,COMPRISING A GUN-LAUNCHED PROJECTILE THAT WAS TO BE UNITED WITH A RAMJET PROPULSION UNIT. THIS WAS TO MAKE IT POSSIBLE TO OBTAIN A LONG-RANGE WITH LOW INITIAL MUZZLE VELOCITIES, ALLOWING HEAVY SHELLS TO BE FIRED FROM RELATIVELY LIGHTWEIGHT GUNS.
THE PROPOSAL FOR FONO'S INVENTION WAS REJECTED BY THE AUSTRO-HUNGARIAN ARMY. A PATENT ON AN AIRCRAFT POWERED BY SUPERSONIC RAMJETS WAS AWARDED TO HIM IN 1932.
IN 1921 THE FIRST PATENT FOR USING A GAS TURBINE TO POWER AN AIRCRAFT WAS FILED BY MAXIME GUILLAUME WITH HIS AXIAL-FLOW TURBOJET ENGINE.

EDGAR BUCKINGHAM WAS SKEPTICAL ABOUT THE IDEA THAT JET ENGINES WOULD BE ECONOMICALLY COMPETITIVE WITH PROP-DRIVEN AIRCRAFT AT LOW ALTITUDES AND AIRSPEEDS OF THE PERIOD. IN 1930 THE PISTON ENGINE WAS THE ONLY POWERPLANT AVAILABLE TO AIRCRAFT DESIGNERS. THE USE OF PISTON ENGINES WAS ACCEPTED ONLY FOR THE LOW-PERFORMANCE AIRCRAFT.

IN 1928 AIR COMMODORE FRANK WHITTLE SUBMITTED HIS IDEAS FOR A TURBOJET TO HIS SUPERIORS. WHITTLE SUBMITTED HIS FIRST PATENT IN 1930 WHICH THEN GOT GRANTED IN1932.

THE PATENT WAS OF A TWO-STAGE AXIAL COMPRESSOR FEEDING A SINGLE-SIDED CENTRIFUGAL COMPRESSOR. WHITTLE CONCENTRATED ON THE SIMPLER CENTRIFUGAL COMPRESSOR ONLY FOR PRACTICAL REASONS. HIS FIRST ENGINE WAS UP AND RUNNING IN APRIL 1937. IT WAS LIQUID-FUELED AND HAD A SELF-CONTAINED FUEL PUMP. SOME PROBLEMS WERE EXPERIENCED WITH THE ENGINE AS IT WOULD NOT STOP, EVEN AFTER THE FUEL WAS SWITCHED OFF IT CARRIED ON ACCELERATING. THE REASON FOR THIS WAS THE FUEL THAT LEAKED AND ACCUMULATED INTO THE ENGINE.

HANS VON OHAIN WORKED ON A SIMILAR DESIGN IN 1935. OHAIN CLAIMED TO BE UNAWARE OF WHITTLE'S WORK, HOWEVER, YEARS LATER HE ADMITTED THAT THIS WAS NOT THE CASE.AS OHAIN'S PATENT WAS NOT FILED UNTIL 1935, THE ADMISSION CLEARLY SHOWS THAT HEHAD READ WHITTLE'S PATENT. HE ALSO CRITIQUED IT IN SOME DETAIL PRIOR TO FILING HIS OWN PATENT. HIS FIRST DEVICE WAS STRICTLY EXPERIMENTAL, IT COULD ONLY RUN UNDER EXTERNAL POWER BUT WAS ABLE TO DEMONSTRATE THE BASIC CONCEPT.
ERNST HEINKEL, GERMAN AIRCRAFT ENGINEER, WHO PURCHASED THE HIRTH ENGINE COMPANY, SAW A LOT OF POTENTIAL IN OHAIN'S DESIGN. OHAIN AND HIS MASTER MACHINIST MAX HAHN WERE SET UP IN THE COMPANY AS A NEW DIVISION OF HIRTH. BY SEPTEMBER 1937 THEIR FIRST HES1 CENTRIFUGAL ENGINE WAS RUNNING. OHAIN USED HYDROGEN AS FUEL SUPPLIED UNDER EXTERNAL PRESSURE. THE GASOLINE FUELLED HES3WAS FITTED TO HEINKEL'S HE178 WHICH WAS THE WORLD'S FIRST TURBOJET-POWERED AIRCRAFT TO FLY.

THE JENDRASSIC CS-1 WHICH WAS DESIGNED BY GYÖRGY JENDRASSIC WAS THE FIRST TURBOPROP IN THE WORLD. THE CS-1 WAS PLANNED TO FIT THE VARGA RMI-1X/HTWIN-ENGINED RECONNAISSANCE BOMBER WHICH WAS DESIGNED BY LASZLO VARGA IN 1940.THE PROGRAM, HOWEVER, GOT CANCELED.

IN 1941 A FLYABLE ENGINE, THE W.1 WHICH WAS DESIGNED BY WHITTLE, WAS FITTED TOTHE GLOSTER E28/39 AIRFRAME WHICH WAS SPECIALLY BUILT FOR IT AND FIRST FLEW ON15 MAY 1941 AT RAF CRANWELL.

BRITISH AIRCRAFT DESIGNER FRANK HALFORD DEVELOPED A “STRAIGHT-THROUGH” VERSION OF THE CENTRIFUGAL JET WHICH WAS KNOWN AS THE DE HAVILLAND GOBLIN. THE PROBLEM WITH THESE CENTRIFUGAL ENGINES WAS THAT THE COMPRESSOR WORKED BY ACCELERATING AIR OUTWARD FROM THE CENTRAL INTAKE TO THE OUTER PERIPHERY OF THE ENGINE,COMPRESSING THE AIR BY A DIVERGENT DUCT SET-UP, CONVERTING ITS VELOCITY INTO PRESSURE.

THE DESIGN WAS WELL UNDERSTOOD AND HAS BEEN IMPLEMENTED IN CENTRIFUGAL SUPERCHARGERS AND ALSO IN WIDESPREAD USE ON PISTON ENGINES. DUE TO TECHNICAL LIMITATIONS ON THE SHAFT SPEED OF THE ENGINE, THE COMPRESSOR NEEDED A LARGE DIAMETER TO PRODUCE THE POWER REQUIRED.
THE ENGINES HAD A LARGE FRONTAL AREA, WHICH MADE IT LESS USEFUL DUE TO DRAG.THE AIRFLOW WAS REVERSED THOUGH THE COMBUSTION SECTION AND AGAIN TO THE TURBINE AND TAILPIPE, MAKING EFFICIENCY COMPLEX. THE ADVANTAGE OF THESE ENGINES WAS THAT THEY WERE LIGHTWEIGHT, SIMPLE AND RELIABLE AND DEVELOPMENT PROGRESSED VERY QUICKLY TO PRACTICAL AIRWORTHY DESIGNS.

THE AXIAL-FLOW COMPRESSOR WAS INTRODUCED BY AUSTRIAN JET ENGINEER ANSELM FRANZ.THIS INITIALLY WAS A TURBINE IN REVERSE. AIR COMING IN THE FRONT OF THE ENGINE IS BLOWN TOWARDS THE REAR OF THE ENGINE BY CONVERGENT DUCTS, IT IS THEN CRUSHED AGAINST A SET OF NON-ROTATING STATORS.

AS THIS PROCESS WAS NOT NEARLY AS POWERFUL AS THE CENTRIFUGAL COMPRESSOR, A NUMBER OF THESE PAIRS OF FANS AND STATORS NEEDED TO BE PLACED IN SERIES TO THE COMPRESSION THAT WAS ACQUIRED. THIS ENGINE WAS MUCH SMALLER IN DIAMETER MAKING IT MUCH MORE AERODYNAMIC.

JUMO WAS ASSIGNED THE NEXT ENGINE NUMBER IN THE RLM NUMBERING SEQUENCE, 4. THIS LED TO THE JUMO 004 ENGINE.
MASS PRODUCTION OF THIS ENGINE STARTED IN 1944 AS A POWERPLANT FOR THE WORLD'SFIRST JET-FIGHTER AIRCRAFT, THE MESSERSCHMIDT ME262, ALSO THE WORLD'S FIRST JET-BOMBER AIRCRAFT, THE ARADO AR 234.

THE HEINKEL-HIRTH AVIATION POWERPLANT CREATED A MORE POWERFUL TURBOJET ENGINE,THE HEINKEL HES011. IT USED A DIAGONAL COMPRESSOR SECTION THAT COMBINED THE FEATURES OF BOTH CENTRIFUGAL AND AXIAL-FLOW COMPRESSOR LAYOUTS FOR TURBOJET POWERPLANTS. SADLY ONLY NINETEEN EXAMPLES WERE PRODUCED.

THE UK'S FIRST AXIAL-FLOW ENGINE, THE METROVICK F.2 WAS MORE POWERFUL THAN THE CENTRIFUGAL DESIGNS BUT WAS CONSIDERED TO BE TOO COMPLEX AND UNRELIABLE BY THE MINISTRY. THE WORK AT METROVICK LED TO THE ARMSTRONG SIDDELEY SAPPHIRE ENGINE THAT WAS BUILT IN THE UNITED STATES AS THE J65.

AFTER THE WWII, THE GERMAN JET AIRCRAFT AND JET ENGINES WERE STUDIED EXTENSIVELY BY GERMANY'S VICTORIOUS ALLIES AND CONTRIBUTED WORK ON EARLY SOVIETAND US JET FIGHTERS. PRACTICALLY ALL JET ENGINES ON FIXED-WING AIRCRAFT HAD SOME INSPIRATION FROM THE AXIAL-FLOW ENGINE.
GREAT IMPROVEMENTS HAVE BEEN MADE ON THE CENTRIFUGAL-FLOW ENGINES AS TECHNOLOGY AND THE SHAFT SPEED OF THE ENGINE WAS INCREASED. THIS LED TO A REDUCTION IN THE DIAMETER OF THE CENTRIFUGAL COMPRESSOR. THE SHORT LENGTH OF THE ENGINES REMAINS AN ADVANTAGE OF THIS DESIGN, THEY ARE ALSO LESS LIABLE TO FOREIGN OBJECT DAMAGE THAN AXIAL-FLOW COMPRESSOR ENGINES.

GERMAN DESIGNS WERE MORE ADVANCED AERODYNAMICALLY, BUT THE LACK OF REQUISITE RARE METALS SUCH AS TUNGSTEN, CHROMIUM, AND TITANIUM, FOR HIGH-STRESS COMPONENTS SUCH AS TURBINE BLADES AND BEARINGS MEANT THAT GERMAN ENGINES HAD ASHORT SERVICE LIFE.

BRITISH ENGINES WERE MANUFACTURED UNDER LICENSE IN THE US AND WERE SOLD TO SOVIET RUSSIA. THEY REVERSE-ENGINEERED THEM WITH THE NENE TO POWER THE FAMOUS MIG-15.

BOTH AMERICAN AND SOVIET DESIGNS STRIVED TO ATTAIN SUPERIOR PERFORMANCE UNTIL THE 1960S. THE JET ENGINE WAS ALMOST UNIVERSAL IN COMBAT AIRCRAFT BY THE 1950S;THE ONLY EXCEPTIONS WERE CARGO, LIAISON AND SPECIALTY TYPES.

SOME BRITISH DESIGNS WERE ALSO CLEARED FOR CIVILIAN USE AND APPEARED ON EARLY MODELS LIKE THE DE HAVILLAND COMET AND AVRO CANADA JETLINER. BY THE 1960S
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LARGE CIVILIAN AIRCRAFTS WERE JET-POWERED. PISTON ENGINES WERE LEFT FOR LOW-COST NICHE ROLESSUCH AS CARGO FLIGHTS.

THE PISTON ENGINE WAS PUSHED OUT OF THE MAINSTREAM ENTIRELY BY THE TURBOPROP,IT ONLY SERVED THE SMALLEST GENERAL AVIATION DESIGNS AND HAD SOME USE IN DRONE AIRCRAFT.

THE ASCENSION OF THE JET ENGINE TO ALMOST UNIVERSAL USE IN AIRCRAFT TOOK OVER20 YEARS TO ACHIEVE. THE EFFICIENCY OF TURBOJET ENGINES WAS STILL WORSE THAN PISTON ENGINES, HOWEVER BY THE 1970S WITH THE ARRIVAL OF HIGH BYPASS JETENGINES, AN INNOVATION AT HIGH SPEEDS AND HIGH ALTITUDES THAT SEEMED ABSURD,ONLY THEN DID THE FUEL EFFICIENCY FINALLY EXCEED THAT OF THE BEST PISTON AND PROPELLER ENGINES.
FAST, SAFE AND ECONOMICAL TRAVEL HAD FINALLY ARRIVED AND PREDICTIONS THAT JETENGINES WOULD NEVER AMOUNT TO MUCH DISAPPEARED FOREVER.

THE JET ENGINE DID NOT ONLY PLAY A MAGNIFICENT ROLE IN THE HISTORY OF AVIATION,BUT ALSO IN THE WORLD OF MECHANICAL AND INDUSTRIAL ENGINEERING. IN FACT, IT WASA DEFENSE FORCE PROTOTYPE THAT WAS NEVER PUT INTO PRODUCTION THAT WAS THE INSPIRATION BEHIND SUPER VELOCE'S AVIATORE VELOCE ESPRESSO MACHINE. HANDCRAFTED IN AEROSPACE-GRADE MATERIALS SUCH AS TITANIUM, SURGICAL STAINLESS STEEL, AND ALUMINUM ALLOY, THE AVIATORE IS AN EXACT QUARTER-SCALE RECREATION OF A JET ENGINE.THE VISION OF CEO AND FOUNDER OF SUPER VELOCE, PAOLO MASTROGIUSEPPE, CAME TOLIFE WHEN THE TWO WORLDS OF AVIATION AND COFFEE COLLIDED TO CREATE THIS TRULY ONE OF A KIND MASTERPIECE THAT IS THE AVIATORE.