RATEAU, AUGUSTE CAMILLE EDMOND

(b. Royan, Charente-Maritime, France, 13 October 1863; d. Paris, France, 13 January 1930)

fluid mechanics, turbomachinery.

Rateau’s father, also named Auguste, listed his occupation as “entrepreneur des travaux publics”; his mother was Lucie Chardavoine. He graduated at the top of his class at the école Polytechnique in 1883 and chose service in the Corps des Mines. During 1885 he made an extensive tour of technical installations in Belgium, Germany, Austria-Hungary, Italy, and Russia. He was promoted through the grades of third-, second-, and first-class student engineer, then third-, second-, and first-class ingénieur ordinaire, attaining the last rank in 1898.

In 1888 Rateau was named professor at the Ècole des Mines at St. Ètienne, a post he held for the next decade. He combined teaching duties with mining and railroad assignments in central and southern France. While on leave from the Corps des Mines during 1899, he served as secretary to the Commission on Construction Materials and as consultant to the firm of Houilteres de St. diamond. While at St. Ètienne he became interested in mine ventilation, and this led to his lifelong interest in turbomachinery. He designed centrifugal pumps and multistage centrifugal gas compressors.

Rateau was appointed professor at the Ècole Supérieure des Mines at Paris in 1902. The following year he formed his own company, Soeiété Rateau, to manufacture his turbomachines. Sautter-Harlé et Cie. also manufactured apparatus and equipment designed by Rateau. During World War I he operated a munitions factory while continuing his research in other areas.

In the power industry Rateau is remembered primarily for his steam turbine. Before this, C. G. P de Laval had developed the high-speed single-stage steam turbine, which required reduction gearing for most applications and was limited in capacity. In England, Charles Parsons had developed a multistage steam turbine in which relatively small pressure drops were used in the nozzles and the moving blades. Rateau is credited with the invention of the pressure stage impulse turbine. He restricted the expansion of steam to the nozzles but used larger pressure drops per stage. In his design the rotors were separated by diaphragms which contained the nozzles. This reduced the number of stages for a given power output and shortened the distance between bearings. The Rateau turbine has been dated at 1901; the U.S. patent was issued in 1903. His turbine found wide acceptance in both marine and central station applications. The use of a single Curtis wheel (velocity staging), followed by a number of Rateau stages (pressure staging), characterized General Electric Company practice in the United States over the succeeding half-century. The combination is still widely used today.

In the analysis of heat-power cycles. Rateau appreciated the advantages of thermal storage and was one of the early advocates of the steam accumulator. In mines and mills he applied low-pressure condensing steam turbines, which operated on steam exhausted from reciprocating engines.

Rateau performed many experiments on ejectors and proposed theoretical explanations for their performance. His investigations on the (low of water through nozzles and on the flow of steam through nozzles were widely acknowledged. His work in machine design led to such diverse results as a new deflection equation for Belleville springs, minimum friction gearing, a muzzle brake for artillery, stereooptics for motion pictures, and servo systems for governing steam turbines

As early as 1900 Rateau was interested in the problems associated with aviation. He studied aircraft performance, wing sections, and aircraft propellers, confirming his calculations with wind tunnel tests. Although Rateau did not invent the turbosuper-charger, he was perhaps the first to apply it to aircraft engines (1916–1917). He investigated the effect of the supercharged engine on the range and altitude capabilities of airplanes.

The Académic des Sciences awarded Rateau the Prix Laplace (1883), the Prix Fourneyron (1899), and the Prix Poncelet (1911). He was elected to the Institut de France in 1911 and to the Academie des Sciences in 1918. He was an honorary member of the American Society of Mechanical Engineers and of the Institution of Mechanical Engineers (London). In 1922 the latter organization awarded him the Hawkesley Medal. He was made a commander of the Legion of Honor in 1925. Honorary doctorates were conferred upon him by the universities of Louvain, Birmingham, and Wisconsin, and the Berlin Technische Hochschuie.

BIBLIOGRAPHY

I. Original Works. Rateau’s books are Études sur les appareils Picard pour la vaporisation des dissolutions salees et sur l’emploi du travail pour obtenir de la chaleur (Paris, 1888); Considérations sur turbo-machines, et particulièrenwnt sur les ventilateurs (St. Étienne, 1892);HypothÈse des cloches sous-continentales (Paris, 1893); Recherches expÉrimentales sur l’ecoulement de la vapeur d’ eau par les tuyeres et les orifices (Paris, 1902); Rapport sur les freins de bouche: thÉorie gÉnÉrale—Calculs pratiques—RÉsultats expÉrimentaux (Paris, 1911); ExpÉriences d’Allevard sur les coups de bÉlier (St. Cloud, 1914); Étude thÉorique et expÉrimentale sur les coups de bÉlier dans les conduites forcÉes(Paris, 1917), written with Jouquet and de Sparre; Travaux scientifiques et techniques (Paris, 1917); ThÉorie des hÉliees proputlsives marines et aÉrienne et des avions en vol rectiligne(Paris, 1920); and Turbines hydrauliques (Paris, 1926), written with D. Eydoux and M. Garril.

On turbomachinery see also “Sur les turbo-machines,” in Comptes rendus hebdomadaires des sÉances de l’AcadÉmie des sciences, 113 (1891); 463–465; “Considerations sur les turbo-machines.” in Bulletin de la SociÉtÉ de l’industrie minÉrale 3rd ser, 6 (1892), 47–228; “Ventilateurs et pompes centrifuges pour haute pressions,” ibid., 1. (1902), 73–141; “Steam Turbines” inEngineering, 76 (1903), 32, 105–106; “Steam Turbine Propulsion for Marine Purposes” in Mechanical Engineering, 26 (1904), 487–493; and “Turbo-compresseurs à haute pression et utilisation des vapeurs d”echappement,” in Bulletin de la Soeiété de l’industrie minercde, 9 (1908), 569–595. On steam accumulators and machinery see “Recuperateur de vapeur,” in Revue de Mecanique, 8 (1901), 485–486; “Recuperateur de vapeur Rateau,” ibid., 12 (1903), 385–391; “Essais fait au mois d’Avril 1902 sur la turbine Rateau a basse pression des mines de Bruay,” ibid., 12 (1903), 400–402; “Développement des turbines à vapeur d’echappement,” ibid., 21 (1907), 356–387; “Perfectionner en quelque point la theorie des trompes” in Comptes rendus hebdomadairesdes séances de l’Academic des sciences, ,129 (1899), 1077–1078; “Nouvelle theorie des trompes,” in Revue de Mecanique, 7 (1900), 265–314; “Theorie des ejecto-condenseurs,”ibid., 10 (1902), 300–301, 533–559; “Sur la theorie generate du mouvement varie de Teau les tuyaux de conduite,” ibid., 14 (1904), 1–9; “Etatssuccessifs d’un gaz a haute pression dans un recipient qui se vide par une tuyere,” in Comptes rendtts hebdomadaires des seances de I1 Academic des sciences, 168 (1919), 435–439; “Quanthc de mouvemeni totale et vitesse moyenne du jet de gaz sortant d’un reservoir qui se vide par une tuyere,” ibid., 581–587; “Formule pratique pour le calcul des Rondelles Belleville,” ibid., 104 (1887), 1690; “Sur les engrenages sans frottement,” ibid., 114 (1892), 580–582; “Adresse quelques indications sur un projet d’appareii qui permettrait d^btenir la vision stereoscopique en cinematographic,” Ibid., 127 (1898), 139; and “Etude theorique et experimental sur les coups de belier dans les conduitcs forcees,” ibid., 174 (1922), 1598–1604.

For his work on aircraft see “Theorie des helices propulsives,“in Comptes rendus hebdomadaires des seances de rAcademic des sciences, 130 (1900), 486–489, 702–705; “Theorie des helices et des surfaces sustentrices,” in Revue de Mecanique, 25 (1909), 117–130; “Methode d’experienccs pour rccherches aerodynamique,” in Comptes rendus de r Academic des sciences, 148 (1909), 1662–1664; “Etude de la poussee de Pair sur un surface” ibid., 149 (1909), 260–263; “Theorie du vol des aeroplanes aux diverses altitudes,” ibid., 168 (1919), 1142–1147; “Suite de la theorie des aeroplanes,” ibid., 1246–1251; and “Theorie de la montee rectiligne des aeroplanes,” ibid., 1295–1301. On superchargers, sec “Theorie generate du turbo-compresseur pour motcurs d’avions,” ibid, 174 (1922), 1511–1516; and fc’Calcul des variations du plafond d’un aeroplane dues a une variation de son poids ou a femploi d’un turbo-compresseur,” ibid., 1669–1674.

II. Secondary Literature. On Rateau’s work see C. Dornier, Beitrag zur Berechnung der Luftschrauben (Berlin, 1912); A.J.Buchi, Exhaust Turbocharging of Internal Combustion Engines (Philadelphia, 1953); and E. T. Vincent, Supercharging the Internal Combustion Engine (New York, 1948). An obituary is H. H. Supplee, “Auguste C. E. Rateau,” in Mechanical Engineering, 52 (1930), 571.

James H. Potter