Henri Coandă

Lore & Background

Born in Bucharest, Coandă was the second child of a large family. His father was General Constantin Coandă, a mathematics professor, and his mother was Aida Danet. He attended elementary school in Bucharest, then secondary school at Liceu Sf. Sava, before his father transferred him to a military high school in Iaşi. He graduated in 1903 as sergeant major and continued at the School of Artillery, Military, and Naval Engineering in Bucharest. Sent to Germany in 1904, he enrolled at the Technische Hochschule in Charlottenburg, Berlin. He graduated as an artillery officer but was more interested in flight. He studied at the Montefiore Institute in Liège, Belgium, where he met Gianni Caproni, then returned to Romania as an active officer before leaving the army.

In 1909 he went to Paris, enrolling at the École des Arts et Métiers and later at the École Supérieure d'Aéronautique et de Constructions Mécaniques (which later became SUPAERO), graduating at the head of the first class in 1911. That year, in Caproni's workshop, he designed and built the Coandă-1910, displayed at the second International Aeronautic Salon in Paris. The aircraft used a piston engine to power a rotary compressor for propulsion. Contemporary sources described it as incapable of flight. Years later, after others developed jet technology, Coandă claimed it was a motorjet that actually flew, but Charles Gibbs-Smith noted the machine never flew, was never destroyed on test, and was sold to a Monsieur Weyman. Between 1911 and 1914 he worked as technical manager of the Bristol Aeroplane Company, designing Bristol-Coanda Monoplanes. In 1915 he returned to France, designing propeller aeroplanes for Delaunay-Belleville, including the Coandă-1916 with tail-mounted propellers. In the interwar years he continued inventing, and in 1934 was granted a French patent related to the Coandă effect. He designed a disc-shaped 'flying saucer' aircraft called Aerodina Lenticulară, but no full-scale version was built.

During World War II, Coandă worked in occupied France for the Nazis, developing turbopropeller drive systems, though the specific details of his wartime projects remain unclear and the contract yielded no production plans. After the war, his research on the Coandă effect was used in investigations of entrained flow, leading to applications in packaging machinery and bladeless fans.

Reader's Guide

Henri Coandă is significant primarily for discovering the Coandă effect, a fluid dynamics phenomenon where a jet of fluid attaches to a nearby surface. This effect has been applied in various fields, from aeronautics to consumer products like the Dyson Air Multiplier fan. His early experimental aircraft, the Coandă-1910, is historically notable but controversial: while Coandă later claimed it was the first jet aircraft, contemporary sources and later historians like Charles Gibbs-Smith refute that it ever flew or incorporated jet propulsion. The aircraft's ducted fan design was described in a patent as working with either water or air, not as a jet engine. Coandă's later work included designing a 'flying saucer' and contributing to the Sud Aviation Caravelle's tail-mounted engine layout. His legacy is mixed: he was a prolific inventor with many patents, but his self-aggrandizement in the 1950s regarding aviation history has led to ongoing debate among historians. Nonetheless, the Coandă effect remains a widely recognized and applied principle, and his name is memorialized at Bucharest's Henri Coandă International Airport.

Did You Know?

• The Coandă-1910 aircraft was displayed at the second International Aeronautic Salon in Paris in 1910.
• He worked for the Nazis during World War II developing a turbopropeller drive system for snow sleds.