György Jendrassik

György Jendrassik or George Jendrassik (1898 Budapest – 1954 London) was a Hungarian physicist and mechanical engineer.

Jendrassik completed his education at Budapest's József Technical University, then at the University of Berlin, where he attended lectures of the famous physicists Albert Einstein and Max Planck. In 1922, he obtained his diploma in mechanical engineering in Budapest. From 1927 onward, he worked at Ganz Rt, where he helped to develop diesel engines, of which the first few pieces were made with single and double cylinders. Later, the 4- and 6-cylinder four-stroke versions were developed, without compression and with mixing chamber.

Diesel Engines

Jendrassik started working at Ganz and Company - Danubius Electricity, Machine, Waggon and Shipyard Ltd. He started his activities within the Study Department, which was the development and experimental department. His first work included the strength calculation and preparation of the load tests for the main girders of a new type of wagon for the Dutch coastal local railways. At this time, the main focus of the Study Department was the development of a medium-speed semi-diesel engine. This gave Jendrassik the opportunity to study the theoretical and practical problems of the diesel engine. Jendrassik's interest soon turned to the development of diesel engines. He developed a number of patents which laid the foundations for the development of small and medium-performance diesel engines for use in vehicles. After two years of development work, the Jm 130 single-cylinder engine was produced in 1927. It had a bore of 130 mm, a stroke of 160 mm, and produced 12 hp at 1000 rpm with a specific consumption of 210 grams. This was later developed into two-, four- and six-cylinder versions, which were stable, suitable for rail and marine propulsion, and which featured a combustion chamber in the front. In 1927, seeing the success of the diesel engines, Jendrassik developed the first patents and engines within the Study Department, and in the summer of 1927 the independent Jendrassik Engine Construction Department was established. This department continued to operate after Jendrassik's death until the end of 1958. The Ganz-Jendrassik engines were the start of the motorisation of the railways, but diesel engines were also used in shipping and road vehicles.

His patents and invetions were bought by several major engine manufacturers in Europe, including the Hispano-Suiza and the British Vickers, which were the leading engine manufacturers at the time. Jendrassik was fluent in German, French, English and Spanish, due to his frequent trips to the headquarters of large Western European engineering companies in the affairs of the Ganz company and in the case of the sale of his own patents. He set up a private office in 1934, where he and his colleagues designed a six-cylinder V-type diesel engine for Hispano-Suiza. He also maintained his own office alongside Ganz Rt.

In 1934, he married Johanna Schmall, the eldest daughter of Henrik Schmall, a qualified architect. The increasingly perfected Jendrassik engines became known all over the world and enhanced the reputation of Hungarian industry, the Ganz factory and not least György Jendrassik. In addition to his constant engine development activities, he was also involved in the realisation of gas turbines. In his private office, the thermodynamic calculations for the future gas turbine were carried out.

Turboprop

Later on, Jendrassik worked on gas turbines and in order to speed up research, he established the Invention Development and Marketing Co. Ltd. in 1936. The next year he successfully ran a small experimental gas turbine engine of 100 hp.

Jendrassik next began work on a larger turboprop engine, which would emerge as the CS-1 prototype, produced and tested in the Ganz works in Budapest. Of axial-flow design with 15-stage compressor and 7-stage turbine, it incorporated many modern features. With predicted output of 1,000 bhp at 13,500 rpm the Cs-1 stirred interest in the Hungarian aircraft industry with its potential to power a modern generation of high-performance aircraft, and construction was begun of a twin-engined fighter-bomber, the Varga RMI-1 X/H, to be powered by it. Its first bench run took place in 1940, making it the world's first turboprop engine to run. However, combustion problems were experienced which limited the output to around 400 bhp. Development was discontinued in 1941, when an agreement was reached to manufacture the Daimler-Benz DB 605 engine in Hungary.

Jendrassik's became the factory's managing director from 1942 to 1945. In recognition of his scientific work, in 1943 he was elected as a corresponding member of the Hungarian Academy of Sciences.

In Exile

After World War II, he was not able to continue developing gas turbines. As a successful entrepreneur, political distrust surrounded him in the new communist-dominated Hungary. Before the nationalization of large companies, the communist party of Mátyás Rákosi carried out a large-scale political campaign and disparaging propaganda activities against the rich industrialists and large entrepreneurs, and made the rich socially responsible for the poverty after the war. Jendrassik no longer felt safe in Hungary. After a spell in Argentina, he came to London in 1948 to become consultant and director to Metropolitan Railcars Ltd., controlled by Metropolitan Cammell and Metropolitan-Vickers. Since 1949, Jendrassik has also been an external consultant of Power Jets (Research and Development) Ltd., with which he worked with until his death, on the development of a pressure exchanger; this is a promising type of heat engine in which the compression and expansion of a gaseous medium is effected by direct action of the gases involved without the employment of mechanical parts such ad pistons or blades The number of his inventions on record only in Hungary is 77. His last invention of great importance was the pressure-compensating device for jet engines at the Power Jets Ltd.

Patents in Hungary

During his lifetime, he has been listed on 60 patent applications in Hungary:

Hungarian patent number	Date of filing	Department code	Title of the patent
94510	09.09.1924	V/d/2	Internal combustion engine and method of operation thereof
94538	21.05.1926	V/d/2	Internal combustion engine with variable torque over a wide range
94953	30.09.1926	V/d/2	The fuel pump operating mechanism for internal combustion engines
95627	21.04.1927	V/d/2	Compressorless fuel injection internal combustion engine
98058	22.11.1927	V/e/1	Valve, mainly for fuel pumps or carburettors for thermal power engines
99445	25.06.1928	V/d/2	Device for operating a fuel pump
99555	22.05.1928	V/d/3	Sickle shaped working chamber, roller pump or motor
100249	12.03.1929	XXI/c	Diffuser, mainly for centrifugal pumps and compressors
101099	22.03.1929	V/d/1	Radial flow gas turbine wheel, mainly for constant pressure gas turbines
102168	01.01.1930	V/d/2	Compressorless fuel injection internal combustion engine
102467	21.11.1929	V/d/2	Stroke governor for spring-loaded fuel pumps with buffer stroke
103750	03.07.1930	V/d/2	Flushing pump for internal combustion engines
103785	05.04.1930	V/d/2	Equipment for cooling pistons of internal combustion engines with lubricating oil
103968	06.05.1930	XXI/c	Piston pump
104125	02.08.1930	V/d/2	Piston pump or engine
104590	10.07.1930	V/d/2	Equipment to facilitate starting of power engines
105614	19.02.19.19.19.31.	V/e/2	Method and apparatus for storing energy of currents and returning the stored energy
105664	30.11.1928	V/d/2	Bypass bore or duct for partitions and baffles in the combustion chamber of internal combustion engines with a prechamber system
105928	07.02.1930	V/d/2	Fuel pump actuator
106412	16.10.1930	XXI/c	Process and apparatus for the transfer of energy between fluid media
106453	30.05.1931	XXI/c	Suction equipment for pumps, especially centrifugal pumps
108105	02.03.1932	V/e/1	Equipment for increasing the heat transfer of fluids flowing in tubes
108126	1932.04.05.	V/d/2	Method for eliminating harmful pressure surges in the injection bodies of diesel engines without compressors
109447	10.01.1933	XVIII/a	Cooling or heating surfaces for liquid or gaseous media
109728	08.04.1930	V/d/2	Two-stroke internal combustion engine
111353	11.11.1933	V/d/2	Method and apparatus for cooling main and crank pins of rotary shaft valves, especially of internal combustion engines
111446	23.09.1933	V/d/2	Bypass bore or duct for combustion chamber bulkheads and baffles of internal combustion engines with pre-chamber system
111648	14.01.1933	V/d/2	Equipment for fixing antechambers, air receivers, etc. in the cylinder heads of internal combustion engines
113629	22.03.1935.	V/e/1	Gland plate
114505	01.04.1935	V/d	Operating procedure and equipment for gas turbines
114689	15.06.1935	V/d/3	Drive rods, especially for high-speed engines
114740	09.04.1935	V/d/2	Operating procedure and equipment for internal combustion piston engines, mainly for vehicles
117387	10.06.1936	V/d/2	Equipment for the operational control of engines for motor vehicles
117559	09.07.1936	V/e/1	Piston ring pair in a common piston groove
119895	13.02.1937	V/d/2	Working procedure for gas turbines and gas turbine for carrying out the procedure
120477	31.05.1935	XXI/c	Rotary aerodynamic compressor
120831	24.12.1937	V/d/1	Control method for gas turbines and gas turbine for use therewith
120860	26.06.1937	V/d/2	Equipment for gas turbines
121918	26.01.1938	V/d/2	Operating procedure for combustion turbines and turbine equipment for carrying out the procedure
121919	16.04.1938	V/d/2	Operating procedure and equipment for gas turbines
123678	12.07.1938	V/d/2	Process for a group of machines comprising in series and mechanically independent turbines and associated equipment
123679	14.07.1938	V/d/2	Procedure for the control of gas turbines and associated equipment
124290	11.04.1939	V/d/2	Operation procedure and equipment for gas turbines
126422	02.08.1939	V/d/2	Heat exchanger
128044	26.07.1940	V/d/2	Method and apparatus for gas turbine valves for changing the rotational sense of the machinery unit performing the useful work
128045	17.10.1940	XXI/c	Process and apparatus for compressor plants for controlling the quantity of working fluid delivered
128611	28.08.1940	V/d/2	Support system for bearings for rotating machines with hot working fluid, mainly gas and steam turbines
130185	03.07.1941	V/e/1	Equipment for damping torsional vibrations
131263	20.12.1941	XVIII/b	Dry quenching method and equipment
132904	26.02.1942	V/d/2	Procedure and apparatus for controlling the operation of gas turbines
133514	22.05.1942	II/h	Heat exchanger
134340	26.11.1942	V/d/1	Caloric turbine, mainly gas turbine
134341	26.11.1942	V/d/1	Caloric turbine, mainly gas turbine
135274	16.04.1943	II/h	Surface heat exchanger, mainly cooling
136421	13.07.1943	V/d/2	Process for the operation of rotating machines with blades of a periodic type according to a periodic operating process, and machine or mechanical apparatus for carrying out the process
136611	28.01.1943	II/h	Heat exchanger with thermal storage
137368	21.06.1943	V/d/1	Process for the operation of rotary machines with paddle-cosmos in alternating flow direction and rotary machines for carrying out the process
138415	10.11.1942	V/d/2	Method and apparatus for the control of variable speed turbine gas turbine plants
139149	12.02.1946	XVIII/h	Process and apparatus for cooling high temperature gaseous media