Hot air engine, developed and patented by Traian Vuia, a Romanian performance for 21st century


  • Dumitru Mihalcea Corresponding address: str. Donath nr.17, bl.M2, ap. 37, 400301 Cluj Napoca, Romania


Carnot, Stirling, Ericsson, Joule, Brayton, engines, almost perfect thermodynamic engines Vuia and Pomojnicu, engines with external combustion, isothermate compression and expansion, isentropic, adiabatic, isodiabatic heat release and receipt, regenerator, recuperator


After thoroughly researching data from national archives, libraries, and important technical studies from Romania and abroad, I concluded that the hot air and closed-circuit engine built, tested, and patented by Romanian engineer Traian Vuia (1872–1950), is superior in its thermodynamic performances to similar engines investigated today. For this engine, almost as perfect thermodynamic Carnot engine, Traian Vuia has achieved ten (10) patents, during 1908-1916 years. Therefore, this engine unjustified forgotten or ignored over a century should be considered a wealth, which belongs (inter) national technical heritage. It represents a great challenge to bring this engine back to the scientific and industrial circuit and, in order to do so, this paper clarifies the following issues: • How evolved over time thermal cycling of different engines, as target perfect thermodynamic engine Carnot; • Which was the thermal process used at Vuia engine for isothermation of compression and expansion; • Today “isodiabate heat release and receipt” at Vuia engine can be qualified as an isentropic process for ideal conditions or adiabatic process for real conditions, with irreversibility, or others; • Which device used Traian Vuia for “isodiabate heat release and receipt”; • Which is the construction and operation of Vuia engine; • If thermal cycle and engine Vuia has been recognized internationally.


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