Johann Nikuradse
Encyclopedia
Johann Nikuradse (November 20, 1894 – July 18, 1979) was a Georgia
-born German
engineer and physicist. His brother, Alexander Nikuradse
, was also a Germany-based physicist and geopolitician known for his ties with Alfred Rosenberg
and for his role in saving many Georgians during World War II
.
He was born in Samtredia
, Georgia (then part of the Kutais Governorate, Imperial Russia) and studied at Kutaisi
. In 1919, through the recommendations of the conspicuous Georgian scholar Petre Melikishvili
, he went abroad for further studies. The 1921 Sovietization of Georgia precluded his return to homeland and Nikuradse naturalized as a German citizen.
As PhD
student of Ludwig Prandtl in 1920, he later worked as a researcher at the Kaiser Wilhelm Institute for Flow Research (now the Max Planck Institute for Dynamics and Self-Organization
). He succeeded in putting himself in Prandtl’s favour and thus advanced to the position of department head. In spite of his close ties with the Nazi Party, Nikuradse came, in the early 1930s, under fire of the Institute’s National Socialist Factory Cell Organization whose members accused him of spying for the Soviet Union
and of stealing books from the institute. Prandtl initially defended Nikuradse, but was eventually forced to dismiss him in 1934. He then served as a professor at the University of Breslau (1934–1945), and an honorary professor at the Aachen Technical University
since 1945.
Nikuradse lived mostly in Göttingen
and engaged in hydrodynamics. His best known experiment was published in Germany in 1933. Nikuradse carefully measured the friction a turbulent fluid experiences as it flows down a rough pipe, He used grains of sand of different roughnesses and discovered that the rougher the surface, the greater the friction, and hence pressure loss.
He discovered that:
Georgia (country)
Georgia is a sovereign state in the Caucasus region of Eurasia. Located at the crossroads of Western Asia and Eastern Europe, it is bounded to the west by the Black Sea, to the north by Russia, to the southwest by Turkey, to the south by Armenia, and to the southeast by Azerbaijan. The capital of...
-born German
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
engineer and physicist. His brother, Alexander Nikuradse
Alexander Nikuradse
Alexander Nikuradse , also known by his pseudonym Al. Sanders, was a Georgian-German physicist and political scientist....
, was also a Germany-based physicist and geopolitician known for his ties with Alfred Rosenberg
Alfred Rosenberg
' was an early and intellectually influential member of the Nazi Party. Rosenberg was first introduced to Adolf Hitler by Dietrich Eckart; he later held several important posts in the Nazi government...
and for his role in saving many Georgians during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
.
He was born in Samtredia
Samtredia
Samtredia is a town in Imereti, Georgia, lying in a lowland between the rivers Rioni and Tskhenis-Tsqali, 244 km west of Tbilisi, and 27 km west of Kutaisi, the nation’s capital and the second largest city respectively. Georgia’s most important roads and railways converge there, making Samtredia...
, Georgia (then part of the Kutais Governorate, Imperial Russia) and studied at Kutaisi
Kutaisi
Kutaisi is Georgia's second largest city and the capital of the western region of Imereti. It is 221 km to the west of Tbilisi.-Geography:...
. In 1919, through the recommendations of the conspicuous Georgian scholar Petre Melikishvili
Petre Melikishvili
thumb|right|250px|Petre Melikishvili Petre Melikishvili Georgian chemist . He was the co-founder of Tbilisi State University and the first Rector of TSU.- Biography :...
, he went abroad for further studies. The 1921 Sovietization of Georgia precluded his return to homeland and Nikuradse naturalized as a German citizen.
As PhD
PHD
PHD may refer to:*Ph.D., a doctorate of philosophy*Ph.D. , a 1980s British group*PHD finger, a protein sequence*PHD Mountain Software, an outdoor clothing and equipment company*PhD Docbook renderer, an XML renderer...
student of Ludwig Prandtl in 1920, he later worked as a researcher at the Kaiser Wilhelm Institute for Flow Research (now the Max Planck Institute for Dynamics and Self-Organization
Max Planck Institute for Dynamics and Self-Organization
The Max Planck Institute for Dynamics and Self-organisation in Göttingen, Germany, is a research institute for investigations of complex non-equilibrium systems, particularly in physics and biology....
). He succeeded in putting himself in Prandtl’s favour and thus advanced to the position of department head. In spite of his close ties with the Nazi Party, Nikuradse came, in the early 1930s, under fire of the Institute’s National Socialist Factory Cell Organization whose members accused him of spying for the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
and of stealing books from the institute. Prandtl initially defended Nikuradse, but was eventually forced to dismiss him in 1934. He then served as a professor at the University of Breslau (1934–1945), and an honorary professor at the Aachen Technical University
RWTH Aachen
RWTH Aachen University is a research university located in Aachen, North Rhine-Westphalia, Germany with roughly 33,000 students enrolled in 101 study programs....
since 1945.
Nikuradse lived mostly in Göttingen
Göttingen
Göttingen is a university town in Lower Saxony, Germany. It is the capital of the district of Göttingen. The Leine river runs through the town. In 2006 the population was 129,686.-General information:...
and engaged in hydrodynamics. His best known experiment was published in Germany in 1933. Nikuradse carefully measured the friction a turbulent fluid experiences as it flows down a rough pipe, He used grains of sand of different roughnesses and discovered that the rougher the surface, the greater the friction, and hence pressure loss.
He discovered that:
- In range I, for small Reynolds number the resistance factor is the same for rough as for smooth pipes. The projections of the roughening lie entirely within the laminar layer for this range.
- In range II (transition range) an increase in the resistance factor was observed for an increasing Reynolds number. The thickness of the laminar layer is here of the same order of magnitude as that of the projections.
- In range III the resistance factor is independent of the Reynolds number (quadratic law of resistance). Here all the projections of the roughening extend through the laminar layer and the resistance factor
.