Walter Thiel (engineer)

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Walter Thiel (born March 3, 1910 in Breslau ; † August 18, 1943 in Karlshagen ) was a German chemist and rocket engineer . He was largely responsible for the development of the A4 rocket engines.

A4 engine from the inside
Powerplant pot (one of 18) with atomizer nozzles

Life

Walter Erich Oskar Thiel was born as the second son of the married couple Oskar (profession: post assistant) and Elsa Thiel (née Prinz). Thiel's talent was evident early on. After primary school, he received a free place in the Bender secondary school in Breslau because of an intelligence test. After only three months he was able to transfer to the quinta (6th grade) and was always top up to the upper prima (13th grade) .

After he had passed the Abitur in all subjects with "very good" in 1929, he studied at the Technical University of Wroclaw in the Faculty of Materials Management, specializing in chemistry. From the third semester he was granted free studies due to above-average performance .

In the summer semester of 1931 he passed the preliminary diploma examination with distinction. In 1932 Thiel was accepted as a member of the German National Academic Foundation and in the winter semester of 1933 passed the examination to become a qualified engineer (chem.) In all seven subjects with "very good".

In 1934 Thiel received his doctorate from the Humboldt University in Berlin with summa cum laude “On the addition of compounds with a strongly polar carbon- halogen bond to unsaturated hydrocarbons ”.

The Heereswaffenamt recruited him directly from the university for basic missile research. Thiel succeeded Kurt Wahmke , who had died in an accident , in Erich Schumann's laboratory . Like Wahmke, Thiel already had contacts with Walter Dornberger and the Kummersdorf Army Research Center . Presumably this was initiated by Schumann. Thiel probably worked with Wernher von Braun as early as 1934 .

In 1936 he had to complete his military service and was called up as a radio operator in Magdeburg for two months.

In autumn 1936, Walter Dornberger recruited Thiel to the Army Research Center for the development of liquid rockets in Kummersdorf near Berlin. He put Thiel in charge of engine development for the 25 t engine, a great challenge.

In 1937 the first scientists moved from Kummersdorf to Peenemünde. Thiel and his team stayed in Kummersdorf before moving to the Peenemünde Army Research Center (Development Plant East) as head of the engine development department in the summer of 1940 . Thiel was Wernher von Braun's representative in the development plant. In 1940 Konrad Dannenberg joined Thiel's engine team. Dannenberg later worked on the engines in the USA and later at NASA as deputy head of the development program for the Saturn V moon rocket.

In 1943 Thiel and with him many of the Peenemünde researchers were at their nerves. Overwork, pressure to succeed and the change from a development company to a production company weighed on the scientists. Thiel refused to describe the rocket's engine as suitable for mass production and on August 17, 1943, underlined his protest with an oral resignation. He wanted to do his habilitation as a thermodynamicist at a university. Dornberger did not accept the termination.

With Operation Hydra , the Royal Air Force attacked Peenemünde the following night from August 17 to 18, 1943. Thiel was killed by aerial bombs in front of their house in Karlshagen on Hindenburgstrasse in the splinter trench together with his wife Martha, née Strohwald, daughter Sigrid (* March 14, 1936) and son Siegfried (* September 5, 1941). The Thiel family is buried in the Karlshagen cemetery of honor .

On October 29, 1944, Thiel was posthumously awarded the Knight's Cross with Swords of the War Merit Cross.

The moon crater Thiel is named after him.

research results

Walter Thiel provided fundamental and groundbreaking research results for rocket propulsion.

In August 1937, Thiel summarized all previously known rules and fundamentals in the following text: “Empirical and theoretical fundamentals for the recalculation of ovens and test data” (GD 634.190.8, FE 573, Deutsches Museum Munich, German Documents Archive). Thiel is the first to set up the equation that calculates the ratio of the combustion chamber volume (cm³) to the narrowest cross-section (cm²), now known as the "characteristic combustion chamber length" L * (pronounced: L star).

It changes the injection position in the furnace from its central position to an outer one. From there it penetrates the "pot" through holes in the wall. This constructive change is a fundamental "key event" of Walter Thiel's chemodynamic ideas for subsequent solutions.

The advantages of borehole and centrifugal nozzle combustion chambers are on the one hand a cooler wall and on the other hand optimal mixing. A conical or conical head is equipped with several rows of brass fuel nozzle inserts, which have now also been adapted to the thin wall. The “centrifugal force nozzle”, similar to the special nozzle, but radically reduced in length and weight, began its service.

1938: Systematic tests by the Thiel research group on the Kummersdorfer test stand 5 with a combustion chamber emitting 100 kg of thrust (even against negative pressure!) Showed that a total opening angle of the expansion nozzle of up to 30 ° does not cause any jet detachment. From now on, all combustion chambers will be designed with a large extension angle, which by shortening the nozzle will make cooling considerably easier as well as fundamental savings in material, weight and working time. The 25 t kilns to be manufactured in Peenemünde according to the Kummersdorf construction documents would therefore only have a total length of 1.6 m. For comparison: the first variants of a 20 t combustion chamber in 1936 were still 4.2 m.

1939: The philosophy of the arrangement of the optimized atomization system is pure experimentation with various solutions. For the center of gravity of the rocket, too, it is extremely advantageous to build combustion chambers not in length but in width.

An 18-pot stove is created: a main valve in the middle of the head reduces the number of atomizer systems to 18, and this construction is also designed as a three-shell head construction that creates two head spaces: In the lower room, the ethanol cools from the ring collector located at the nozzle mouth the head, flows towards the center of the head, where the valve is located, and flows from there into the space above to the individual "pots". The bores for film cooling introduced shortly afterwards finally thermally stabilized the nozzle.

1941: The final report of the "25.4 t 18-pot oven" is presented by Thiel. The outflow speed is now an average of 2,060 m / s at 16 bar internal pressure. The furnace head made of an aluminum alloy is initially screwed onto the steel nozzle (series A).

1942: The combustion chamber made entirely of steel is ready for the series (series B). The atomization system fixed at this time will not be changed until the end of the war and is even later a model for the combustion chamber RD-100 of the " R-1 " of the USSR, a Soviet replica of the German rocket unit 4 .

October 3, 1942: The first successful start of an A4 in Peenemünde succeeds. The rocket reaches a height of 84.5 km, a speed of 4,824 km / h (5 times the speed of sound) and flies 190 km towards the target location with only a small deviation.

References / literature

  • Bode, Volkhard and Kaiser, Gerhard: rocket tracks. Peenemünde 1936-2004. Berlin: Ch. Links Verlag, 5th edition 2004
  • Federal Archives / Military Archives, Freiburg, German Documents (GD)
  • Federal Archives, Berlin-Lichterfelde (Department: German Reich 1933–1945)
  • Deutsches Museum Munich, Archive, Peenemünde Archive, German Documents (GD)
  • Dornberger, Walter: “Peenemünde. Die Geschichte der V-Waffen ”, Ullstein-Verlag, 6th edition 1995, ISBN 3-548-33119-X , pages: 62–66, 168–169, 185–186
  • Erichsen, Johannes and Hoppe, Bernhard M. (Ed.): Peenemünde. Myth and history of the rocket. 1923-1989. Catalog of the Peenemünde Museum: April 2004.
  • Freeman, Marsha: How we got to the Moon, the Story of the German Space Pioneers, 21st Century Science Associates, Washington DC, 1993.
  • Lange, Thomas H .: “Peenemünde. Analysis of a technology development in the Third Reich ", VDI-Verlag 2006, ISBN 3-18-150050-X , pages: 27, 33, 69, 92, 100
  • Neufeld, Michael J .: "The rocket and the realm", Henschel Verlag, 2nd edition 1999, ISBN 3-89487-325-6 , pages: 75, 94-101, 133, 190, 210, 211, 239
  • Neufeld, Michael J .: "Wernher von Braun", Siedler Verlag, 1st edition, May 2009, ISBN 978-3-88680-912-7 , pages: 109, 129, 132, 133, 140
  • Thiel, Walter: "On the addition of compounds with a strongly polar carbon-halogen bond to unsaturated hydrocarbons", dissertation, Konrad Triltsch Verlag, Würzburg, 1935 (available from: TIB, Hanover)
  • von Braun, Wernher: My life for space travel. Offenburg: Burda Verlag, 1969

Web links