On January 1, 1912, Carl Pfleiderer was named full professor at the then Technical University of Braunschweig at the age of 30. As the successor to Prof. Franke, he was responsible for the fields of general mechanical engineering, (piston) steam engine construction, steam turbines, pumps, blowers and compressors, as well as the theory and design of hydraulic turbines. From 1920, he was in charge of the university's own power plant, which was also used for research and training purposes. Within the university, he assumed various functions. Between 1913 and 1945, he served several times as head of the mechanical engineering department or dean of the faculty, and from 1945 to 1947, he was vice-rector of the university. His outstanding scientific achievements were in the field of centrifugal pump design. He developed the theoretical principles and calculation possibilities and received several patents in Germany and abroad. He published several textbooks and numerous papers and was a contributor to well-known standard works such as 'Die Hütte'. Here he worked on the chapter 'Pumpen' from the 25th edition in 1926 to the 28th edition in 1954. Pfleiderer was also a contributor to the well-known technical encyclopedia "Luegers Lexikon der gesamten Technik und ihrer Hilfswissenschaften" (Lueger's Encyclopedia of All Technology and its Auxiliary Sciences) and wrote, for example, a 12-page article on pumps for the 3rd edition in 1926.
In 1924, the first edition of his main work, "Die Kreiselpumpen" ("Centrifugal Pumps"), was published in five editions by Springer-Verlag and gained international recognition through translations into other languages. Also translated into various languages was his textbook "Fluid Machinery", first published by Springer-Verlag in 1952. In the preface, he defends the summary of the treatment of steam turbines, water turbines and centrifugal pumps under the term "Fluid Machinery" against possible reservations. However, this summary was quickly accepted by experts and soon adopted by many universities as a field of mechanical engineering. Prof. Pfleiderer is also responsible for the so-called reduced power theory in turbomachinery engineering.
Pfleiderer received numerous honors for his scientific achievements and his life's work. On his 70th birthday, he received an honorary doctorate from the TH Stuttgart and the dignity of honorary senator from the TH Braunschweig. He received the Grand Cross of Merit of the Order of Merit of the Federal Republic of Germany on his 75th birthday, on which occasion he also received the rare honor of having his former institute, with the approval of the Ministry, bear his name ever since: PFLEIDERER-INSTITUT FÜR STRÖMUNGSMASCHINEN. Carl Pfleiderer died in Braunschweig on August 7, 1960.
In September 1952, Prof. Hartwig Petermann is appointed as his successor. Due to the war, the institute's offices are still provisionally housed in the former house of the stoker next to the power plant and the working conditions for the scientists are very cramped. Numerous publications show the versatile interests of Prof. Petermann in the field of steam turbines, centrifugal pumps and compressors. A representative example is the paper "Safety device against prolonged operation of axial compressors in the breakaway area", in which a pitot tube is described that is still widely used today - also for research purposes at the Pfleiderer Institute - and is generally referred to as the "Petermann tube". At the end of 1961, a joint building was started for the Institute for Piston Machines and the Institute for Fluid Machinery at Langer Kamp. In July 1963, the topping-out ceremony was held and it took until 1966 until the provisional building in the combined heat and power plant could finally be left and the new building was ready for occupancy. On September 6, 1966, the two institutes were ceremonially inaugurated.
Research has focused on experimental work on centrifugal pumps and fans of all types. Numerous works aim at filling the still existing gaps in the design of centrifugal pumps by systematic parameter variation. Particularly worthy of mention here is the work on flow conditions in seal gaps, i.e. non-contact seals. In 1976, Günter Kosyna received his doctorate with a thesis on the subject: "Investigations of radial flow through seal gaps with flat gap walls taking parallelism errors into account". It was Pfleiderer's wish that the editions of the book "Strömungsmaschinen", which were necessary after his death in 1960, should be edited by Prof. Petermann. In 1964, the 3rd edition of the book was published, which was now called Pfleiderer-Petermann "Strömungsmaschinen". The book was so successful that another 3 editions were necessary until 1990. The book was also translated into Turkish, Spanish and Italian. On the occasion of Pfleiderer's 100th birthday, under the scientific direction of Prof. Petermann, the VDI conference: "Hydraulic Fluid Machinery - C. Pfleiderer Memorial Conference" was held at the TU Braunschweig from October 14 to 16, 1981. The retirement of Prof. Petermann is honored with a scientific colloquium in October 1984.
After more than a year without an institute director, Prof. Dr.-Ing. Günter Kosyna takes up his position at the Pfleiderer Institute at the beginning of 1986. Influenced by 10 years of work in industry, the institute is oriented more towards industry-related research work. With the relations to the former employer, the company Pleuger Unterwasserpumpen, a special test rig for submersible motor pumps is built, which, like all later built test rigs, allows system pressure variation and is therefore particularly suitable for NPSH measurements, i.e. measurements of the suction capacity of pumps. Today's measurement technology allows detailed investigations, so time and/or spatially resolved measurements are standard methods at the Pfleiderer Institute. In addition to the use of telemetry systems for transmitting measured values from rotating systems, the procurement of a PIV system (non-contact velocity measurement method for velocity fields) in 1999 has considerably expanded the investigation methods.
The work already started under Prof. Petermann in the field of axial fans was continued by Prof. Kosyna in close coordination with FLT (Forschungsvereinigung Luft- und Trocknungstechnik im VDMA) and not least intensified by the cooperation with the Institute of Fluid Mechanics and the working group Turbomachinery under Prof. Stark. This led to the construction of the 600mm low-pressure axial compressor test rig in 2000 with BMW-RR as an industrial partner within the framework of a European research project (BRITE/EURAM).
Since the reorganization of the mechanical engineering course at the TU Braunschweig in the 1997/98 winter semester, the Pfleiderer Institute has belonged to the "Energy and Process Engineering" department. Since the 2005/06 winter semester, the Pfleiderer Institute has also been part of the "Aerospace Engineering" department. During a scientific colloquium on March 25, 2011, Prof. Kosyna was bid farewell after 25 years as head of the Pfleiderer Institute for Fluid Machinery at the TU Braunschweig.
Since 2011, Prof. Dr.-Ing. Jens Friedrichs has been head of the institute, which has been renamed the Institute of Jet Propulsion and Turbomachinery. In May 2012, the Institute of Flight Propulsion and Turbomachinery, including the test stands, moved into a new building at the Research Airport Campus.