Wolfgang Haack

Wolfgang Siegfried Haack (born April 24, 1902 in Gotha; November 28, 1994 in Berlin) was a German mathematician.

Life

Wolfgang Haack studied mechanical engineering in Hanover and Mathematics in Jena. There, he earned his doctorate in 1926 at the Friedrich Schiller University in Robert Ph.D. on the topic "The provision of land, whose geodesic lines through the picture in the plane in conics override." After a short research visit in Hamburg and a job as an assistant at the Technical University of Stuttgart he habilitated in 1929 at the TH Danzig with his work on "Affine differential geometry of radiation systems." After his short-term change to the 1935 TH Berlin in 1937, he followed the call to the TH Karlsruhe. During the Second World War was in the arms industry for the Projektildesign. That's why he was wanted in 1944 or the reputation of the TH Berlin did not follow. Finally he took over in 1949 as a successor to George Hamel at the TU Berlin the Department of Mathematics and Mechanics. On his aspiration, but also as a recognition of his achievements in 1964 was for him to the new Department of Computational Mathematics. This he held until his retirement in 1968. In 1992 Haack was appointed as an honorary member of the Society for Applied Mathematics and Mechanics.

Applied mathematics

The interaction of Wolfgang Haack is at the interface between mathematics and mechanics. His research areas ranging from the mechanics of differential geometry and partial differential equations over to the numerical mathematics. In particular, he dealt with both elliptical and with hyperbolic partial differential equations of first order. From the Differntialgeometrie coming, it was Pfaff's differential forms have always had a special concern. From house of engineer, he had always applied in the eye, such as the gas dynamics in Überschallstrmungen. During his time in Berlin, he has a good dozen dissertations supervised. Many of his students have of him pre way in scientific research continue, by itself a scientific career.

Research for the final victory: Haack minimum drag shapes

During World War II, the patriotic-minded Haack was involved in military research. During the war he published an analytical formula for projectile nose cone shapes that exhibit the lowest air resistance depending on caliber or diameter and length or volume and length of the profile. Haacks work was published in 1941 by the Lilienthal society but kept secret during World war II [ [http://www.lima-wiederladetechnik.de/Ballistik/Lilienthal-139-1-Haack.pdf Geschoßformen kleinsten Wellenwiderstandes by W. Haack, Bericht 139 der Lilienthal-Gesellschaft (1941)] ] .

Haack shapes or Sears-Haack bodies are no ogives or constructed from any other geometric figures. The shapes are instead mathematically derived streamlined bodies of revolution for the purpose of minimizing drag. Minimal projectile-shape variations can change the air-resistance and hence the effective range of high powered gun projectiles considerably, especially when they change velocity from the supersonic to the transonic and eventually to subsonic air flow regimes or visa versa during flight. For this kind of applications the Haack shape offers significantly improved characteristics compared to the tangential ogive or even the secant ogive often used for very-low-drag bullets and artillery shells [ [http://www.lima-wiederladetechnik.de/Englisch/Haack_minimum_drag_bullet.htm Haack Minimum Drag Rifle Bullet] ] . Haack shaped projectiles for artillery guns and sniper rifles have been and are currently produced though not during World War II [ [http://www.lima-wiederladetechnik.de/Englisch/LM-Class-Bullets.htm LM Class Bullets, very high BC bullets for windy long Ranges] ] . Besides that Haack shapes are also applied in modern fast flying aircraft. Fighter aircraft are probably good examples of nose shapes optimized for the transonic region, although their nose shapes are often distorted by other considerations of avionics and inlets. For example, an F-16 nose appears to be a very close match to a Haack shape.

"I think it hooks!"

The spread of the German saying, "Ich glaub, es hakt" - "I think it hooks," widespread towards the end of the Second World War, can be attributed to Wolfgang Haack. Originally, this was a mocking reference to the contradiction between the war propaganda-spread belief in a final victory with a miracle weapon, and personally experiencing the everyday grievances, the chaos and the undersupply. The proliferation of the use of the phrase by Front soldiers, occurred when rumours about a new type of projectile so greatly contrasted with the regularity of misfires due to defectively manufactured projectiles. The fact that the original phrase, "I think it haackt" was alleged to fix it, had rapid proliferation.

However, though the context of ironic allusion of the correct spelling was lost early on, shortly after the start of the purchase of the Berlin Zuse a 1958 computer in his group, the erroneous reading of punch cards became known as "haacken."

Pioneer of numerical mathematics

Haack recognized early on the potential of computers for scientific and industrial research. Already in 1950, he established a working group on electronic calculating machines, with the aim that after Darmstadt, Göttingen and Munich and Berlin for the Hochchulstandort an electronic calculator acquired. In addition, he contacted Konrad Zuse. Since the Deutsche Forschungsgemeinschaft was not because of the foreseeable future role of computing machinery for the funding would not arise, met Wolfgang Haack first as a guarantor personally liable for the purchase price of 200000 Mark. It was due to him that, in 1958, the first computer at the TU Berlin was set up. The then expensive and risky acquisition could finally be financed partly through donations, but mainly by the rental of computer time.

References

ee also

*Nose cone design
*Sears-Haack body

External links

* [http://www.lima-wiederladetechnik.de/Englisch/Haack_minimum_drag_bullet.htm Haack Minimum Drag Rifle Bullet]
* [http://www.lima-wiederladetechnik.de/Ballistik/Lilienthal-139-1-Haack.pdf Geschoßformen kleinsten Wellenwiderstandes by W. Haack, Bericht 139 der Lilienthal-Gesellschaft (1941)]