Most people know Thomas Edison for inventing the first practical light bulb. But the GE founder also was a serial entrepreneur whose patents helped spawn new industries including medical imaging, power generation and aviation.
The last two have a long history together. After first playing an important part in bringing electricity to homes and businesses, GE’s expertise in power generation and gas turbine engineering gave birth to the company’s aviation business. Now, aviation engineers are returning the favor by their lending their jet-engine know-how to ultra-efficient gas turbine designs.
People have taken notice. Guinness World Records recently recognized a power plant in Japan that uses a GE turbine as the world’s most efficient combined-cycle power station. And the GE90 engine holds the title of the most powerful jet engine on the planet.
For GE’s engineers, setting new records is practically part of the job description. Relying on new technologies like additive manufacturing, which includes 3D printing, and advanced composite materials, they continue to perfect their turbines. The company also has developed the world’s largest jet engine, the GE9X, which just took its maiden flight. (See top image.)
Take a look at GE Aviation’s and GE Power’s intertwined history:
GE’s journey to making record-breaking jet engines and gas turbines with 3D printed parts started with Edison’s light bulb, and the wave of electric devices that followed created a huge demand for electricity. Initially, companies were using piston engines to power generators, but they quickly switched to more efficient steam turbines. In 1903, GE engineers Charles Curtis and William Emmet built what was then the world’s most powerful steam turbine generator for a power plant in Newport, R.I. (see above). It required one-tenth the space and cost two-thirds as much as the equivalent piston engine generator.
It was also in 1903 that GE hired young turbine engineer Sanford Moss (above). Moss had just received a doctorate in gas turbine research from Cornell University. At GE, he started building a revolutionary radial gas compressor using the centrifugal force to squeeze the air before it enters the gas turbine — the same force pushing riders up into the air on a swing carousel. Moss’s early experiments failed; his machine guzzled too much fuel and produced too little power. But his patent and his revolutionary compressor design were sound and found many applications, from supplying air to blast furnaces to powering pneumatic tube systems. He didn’t know it, but he had pointed the way to the jet engine before the Wright Brothers had even taken off.
In November 1917 – at the peak of World War I – GE President E.W. Rice received a note from the National Advisory Committee for Aeronautics, the predecessor of NASA, asking about Moss’s radial compressor. WWI was the first conflict that involved planes, and the agency wanted Moss to improve the performance of the Liberty aircraft engine. The engine was rated 354 horsepower at sea level, but its output dropped by half in thin air at high altitudes. Moss (at right in the picture above) believed that he could use his compressor to squeeze the air before it enters the engine, making it denser and recovering the engine’s lost power.
Using a mechanical device to fill the cylinders of a piston engine with more air than it would typically ingest is called supercharging. Moss designed a turbosupercharger that used the hot exhaust coming from the Liberty engine to spin his radial turbine and squeeze the air entering the engine. In 1918, when he tested the design at 14,000 feet on top of Pike’s Peak in Colorado, the engine delivered 352 horsepower, essentially its rated sea level output, and GE entered the aviation business.
The first Le Pere biplane powered by a turbosupercharged Liberty engine took off on July 12, 1919. “The General Electric superchargers thus far constructed have been designed to give sea-level absolute pressure at an altitude of 18,000 feet, which involves a compressor that doubles the absolute pressure of the air,” Moss said.
Planes equipped with Moss’s turbosupercharger set several world altitude records.
In 1937, as Hitler’s power was growing, GE received a large order from the Army Air Corps to build turbosuperchargers for Boeing B-17 and Consolidated B-24 bombers, P-38 fighter planes, Republic P-47 Thunderbolts and other planes. GE opened a dedicated Supercharger Department in Lynn, Massachusetts. In 1939, Moss proposed to build one of the first turboprop engines. He later joined the National Aviation Hall of Fame.
GE’s aviation business was just getting started. In 1941, the U.S. government asked GE to bring to production one of the first jet engines developed in England by Sir Frank Whittle. (He was knighted for his feat.) A group of GE engineers called the Hush Hush Boys designed new parts for the engine, redesigned others, tested the engine and delivered a top-secret working prototype called I-A. On Oct. 1, 1942, the first American jet plane, the Bell XP-59A, took off from Lake Muroc in California for a short flight. The jet age in the U.S. had begun. The demand for the first jet engines, called J33 and J35, was so high that GE had a hard a time meeting production numbers, and the Army outsourced manufacturing to General Motors and Allison Engineering.
GE decided to double down and invest in more jet engine research. The J33 and J35 engines used a radial — also called centrifugal — turbine to compress air, similar to the design that Moss developed for his turbosuperchargers. But GE engineers started working on an engine with an axial turbine that pushed air through the engine along its axis. (All jet engines use this design today.) The result was the J47 jet engine that powered everything from fighter jets like the F-86 Sabre to the giant Convair B-36 strategic bombers. GE made 35,000 J47 engines, making it the most-produced jet engine in history.
The J47 also found several off-label applications. The Spirit of America jet car used one, and a pair of them powered what is still the world’s fastest jet-propelled train. They also served on the railroad as heavy-duty snow blowers. In 1948, GE hired German war refugee and aviation pioneer Gerhard Neumann, who quickly went to work on improving the jet engine. He came up with a revolutionary innovation called the variable stator. It allowed pilots to change the pressure inside the turbine and make planes routinely fly faster than the speed of sound. When GE started testing the first jet engine with Neumann’s variable stator, the J79 (see below), engineers thought that their instruments were malfunctioning because of the amount of power it produced. In the 1960s, a GE-powered XB-70 Valkyrie aircraft was flying in excess of Mach 3, three times the speed of sound.
The improved performance made the aviation engineers realize that their variable vanes and other design innovations could also make power plants more efficient. Converting the engines for land use wasn’t difficult. In 1959, they turned a T58 helicopter engine into a turbine that produced 1,000 horsepower and could generate electricity on land and on boats. A similar machine built around the J79 jet generated 15,000 horsepower. In Cincinnati, where GE Aviation moved from Lynn in the 1950s, the local utility built a ring of 10 J79 jet engines to power a big electricity generator. Image credit: GE Aviation.
The first major application of such turbines, which GE calls “aeroderivatives” because of their aviation heritage, was as power plants for the Navy’s 76,000-ton Spruance-class destroyers. The turbines now also power the world’s fastest passenger ship, Francisco. It can carry 1,000 passengers, 150 cars and travel at 58 knots. Image credit: Museum of Innovation and Science Schenectady.
Today, there are thousands of aeroderivatives working all over the world. For example, they have been helping Algeria’s growing economy slake its thirst for electricity. Image credit: GE Power.
Neumann’s variable vanes (above) are also part of GE’s most advanced gas turbine: the 9HA Harriet, the world’s largest, most powerful and most efficient gas turbine. Two of them can generate the same amount of power as a small nuclear power plant. Image credit: GE Power.
GE’s HA-class gas turbines are now also using parts made from ceramic matrix composites, a material that already serves inside the latest jet engines. Components from the material can help make jet engines and gas turbines more efficient. The super-ceramics can withstand temperatures approaching 2,400 degrees Fahrenheit, where even the most advanced alloys grow soft. Image credit: GE Aviation.