Henri Coandă (7 June 1886 – 25 November 1972) was a Romanian inventor, aerodynamics pioneer, and builder of an experimental aircraft, the Coandă-1910 described by Coandă in the mid-1950s as the world’s first jet, a controversial claim disputed by some and supported by others. He invented a great number of devices, designed a “flying saucer” and discovered the Coandă effect of fluid dynamics.

Henri Coanda attended high-school in Bucharest and in Iasi. After this he joined the Bucharest Military School where he graduated as an artillery officer. Fond of technical problems, especially of flight technics, in 1905 he built a ‘missile-airplane’ for the Romanian Army. Then he went up to Berlin to attend studies at Technische Hochschule in Charlottenburg, after which he followed with studies at the Science University in Liege, part of the Electrical Institute in Montefiore(1907-1908), where he met Gianni Caproni. In 1908 Coandă returned to Romania to serve as an active officer in the Second Artillery Regiment. However, his inventor’s spirit did not comport well with military discipline. He solicited and obtained permission to leave the army, after which he took advantage of his renewed freedom to take a long automobile trip to Isfahan, Teheran, and Tibet. Upon his return in 1909, he travelled to Paris, where he enrolled in the newly founded École Nationale Superieure d’Ingenieurs en Construction Aéronautique. One year later (1910) he graduated at the head of the first class of aeronautical engineers.

With the support of engineer Gustave Eiffel and the mathematician, politician, and aeronautical pioneer Paul Painlevé, he began experimenting the aerodynamic techniques: one of this experiments was mounting a device on a train running at 90 km/h so he could analyse the aerodynamic behavior. Another experiment used a wind tunnel with smoke and an aerodynamical balance to profile wings to be used in designing aircraft. This later led to the discovery of the aerodynamic effect now known as the Coandă effect.

• Coandă effect

The Coandă effect is the tendency of a fluid jet to stay attached to a convex surface. As described by the eponymous Henri Coandă in different patents: “the tendency of a jet of fluid emerging from an orifice to follow an adjacent flat or curved surface and to entrain fluid from the surroundings so that a region of lower pressure develops.” The pressure effect, which is usually not indicated, is fundamental for the comprehension of the Coandă effect.

Inventions and discoveries

• 1910: The Coandă-1910, an experimental aircraft constructed on the principle of air-reactive propulsion.
• 1911: An aircraft powered by two engines driving a single propeller – the configuration cancelled the torque of the engines.
• invented a new decorative material for use in construction, beton-bois, used for architectural decorations (the Palace of Culture in Iasi, built in 1925, had been entirely decorated using Coanda’s material);
• 1926: Working in Romania, Coandă developed a device to detect liquids under ground, useful in petroleum prospecting. Shortly thereafter, in the Persian Gulf region, he designed a system for offshore oil drilling.
• The most famous of Coandă’s discoveries is the Coandă Effect. This effect has been utilized in many aeronautical inventions.
• A modular system of sea water desalination and transformation to fresh water , based on solar energy, a clean, ecological and adaptable system.

Over his entire career, Henri Coanda was the author of 250 patents in various fields, receiving also honorary titles, including the membership at the Royal Aeronautical Society of London and the membership at the Romanian Academy. He also received the title of Doctor Honoris Causa at the Polytechnic Institute of Bucharest, where he reorganised the aeronautical engineering catedra, in 1971, with help from the academician Elie Carafoli.