- Year
- 1930
- By
- Roy, Maurice
- Published
- Paris: Ministère de l’Air (sold by Blondel La Rougery and Gauthier-Villars).
- Edition
- French. First edition, softcover.
- Ciancone
- 199.
- Shelf
- R7
- Catalog
- Catalog A · Early Pioneers
No. 1 in the “Publications scientifiques et techniques” series of the French Air Ministry’s aeronautical research service, written by a mining engineer who taught at the École Supérieure de l’Aéronautique and prefaced by the Academician Émile Jouguet. Roy’s introduction is dated 10 October 1930.
It is a purely theoretical comparison, with no tests or hardware, of how efficiently reaction propulsion could drive aircraft compared with the engine-and-propeller system. Part One treats rockets burning powder or ordinary fuel, and “rocket-ejectors” that add an ejector (trompe) to the exhaust; Part Two treats the “reaction propeller,” including a propeller driven only by exhaust jets at its blade tips, which Roy likens to a gas turbine. The results fill numerous tables and graphs.
Jouguet’s preface summarizes the conclusion: engine and propeller remain best at the speeds of modern aircraft, but a reaction propeller or rocket could become interesting beyond roughly 700 to 1,200 km/h; he also notes that rockets are the only conceivable propulsion for interplanetary travel. Three annexes treat viscous gas flow, nozzle theory, and ejector theory.