Jakob Ackeret,

FRAeS The Royal Aeronautical Society, also known as the RAeS, is a British multi-disciplinary professional institution dedicated to the global aerospace community. Founded in 1866, it is the oldest aeronautical society in the world. Members, Fellows ...

(17 March 1898 – 27 March 1981) was a Swiss

aeronautical engineer Aerospace engineering is the primary field of engineering concerned with the development of aircraft and spacecraft. It has two major and overlapping branches: aeronautical engineering and astronautical engineering. Avionics engineering is sim ...

. He is widely viewed as one of the foremost aeronautics experts of the 20th century.

Birth and education

Jakob Ackeret was born in 1898 in Switzerland. He received his diploma degree in

mechanical engineering Mechanical engineering is the study of physical machines that may involve force and movement. It is an engineering branch that combines engineering physics and mathematics principles with materials science, to design, analyze, manufacture, an ...

from

ETH Zurich (colloquially) , former_name = eidgenössische polytechnische Schule , image = ETHZ.JPG , image_size = , established = , type = Public , budget = CHF 1.896 billion (2021) , rector = Günther Dissertori , president = Joël Mesot , ac ...

in 1920 under the supervision of

Aurel Stodola Aurel Boleslav Stodola (11 May 1859 – 25 December 1942) was a Slovak engineer, physicist, and inventor. He was a pioneer in the area of technical thermodynamics and its applications and published his book ''Die Dampfturbine'' (the steam turbine ...

. From 1921 to 1927 he worked with

Ludwig Prandtl Ludwig Prandtl (4 February 1875 – 15 August 1953) was a German fluid dynamicist, physicist and aerospace scientist. He was a pioneer in the development of rigorous systematic mathematical analyses which he used for underlying the science of ...

at the "Aerodynamische Versuchsanstalt" in

Göttingen Göttingen (, , ; nds, Chöttingen) is a college town, university city in Lower Saxony, central Germany, the Capital (political), capital of Göttingen (district), the eponymous district. The River Leine runs through it. At the end of 2019, t ...

, witnessing a legendary period in the development of modern fluid dynamics. He received his PhD from ETH Zurich in 1927.

Academic career

After completing his PhD, Ackeret worked at Escher Wyss AG in Zurich as chief engineer of hydraulics, where he applied, with great success, modern aerodynamics to the design of turbines. He became a professor of

Aerodynamics Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dyn ...

at ETH Zurich in 1931, where

Wernher von Braun Wernher Magnus Maximilian Freiherr von Braun ( , ; 23 March 191216 June 1977) was a German and American aerospace engineer and space architect. He was a member of the Nazi Party and Allgemeine SS, as well as the leading figure in the develop ...

was one of his students.

Research

Ackeret was an expert on gas turbines and was known for his research on propellers and on high-speed propulsion problems. When he was at ETH Zurich, he actively participated in the solution of practical engineering problems, such as the design of variable-pitch propellers for ships and airplanes. His most important invention was the gas turbine with a closed circuit. He made the invention together with C. Keller. Ackeret also contributed significantly to research in supersonic aerodynamics. He led the initial work on calculating the lift and drag on a supersonic airfoil and he proposed the designation of the "

Mach number Mach number (M or Ma) (; ) is a dimensionless quantity in fluid dynamics representing the ratio of flow velocity past a boundary to the local speed of sound. It is named after the Moravian physicist and philosopher Ernst Mach. : \mathrm = \frac ...

" for multiples of the speed of sound."Aeronautical research in Germany: from Lilienthal until today", Volume 147 by Ernst-Heinrich Hirschel, Horst Prem, Gero Madelung On a conference in Rome in 1935 Ackeret presented a design for a

supersonic wind tunnel A supersonic wind tunnel is a wind tunnel that produces supersonic speeds (1.2< M<5) The Mach number and flow are determined by the

. Ackeret was awarded the

Ludwig-Prandtl-Ring The Ludwig Prandtl Ring is the highest award of the Deutsche Gesellschaft für Luft- und Raumfahrt (German Society for Aeronautics and Astronautics), awarded "for outstanding contribution in the field of aerospace engineering". The award is named ...

from the

Deutsche Gesellschaft für Luft- und Raumfahrt German Society for Aeronautics and Astronautics (DGLR; german: Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V.) is a German aerospace society. It was founded in 1912 under the name of ''Wissenschaftliche Gesellschaft für ...

(German Society for Aeronautics and Astronautics) for "outstanding contribution in the field of aerospace engineering" in 1965. In 1976, he was elected foreign associate member of the American

National Academy of Engineering The National Academy of Engineering (NAE) is an American nonprofit, non-governmental organization. The National Academy of Engineering is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy ...

for his "contributions to the understanding of high-speed and supersonic fluid mechanics, leading to significant improvements to the science of flight".

References

External links

Jakob Ackeret

Jakob Ackeret and the "Institut für Aerodynamik (IfA)''
* 1898 births 1981 deaths Aerospace engineers Aerodynamicists ETH Zurich alumni ETH Zurich faculty Ludwig-Prandtl-Ring recipients Foreign associates of the National Academy of Engineering {{Switzerland-scientist-stub