**4.2.1 UDR1 UMGT combustion chamber**

The 2.5 kW UDR1 UMTG is composed of a compressor, a compact air pre-heater (the pressurized air exiting from the compressor is heated by ΔT= 393 K), a combustion chamber and a turbine, that together compose the thermal section; a double effect (reversible) electrical engine for the electric part; a shaft and the bearings for the mechanical, and obviously all the auxiliaries components required, as valves, controllers, and ducts, including the management unit. For safety reasons the cylindrical fuel tanks are external to the metallic UMTG enclosure [Capata & Sciubba, 2010].

Fig. 6. CAD rendering of the combustor with a detailed view of the pre-heater.

The overall length of the assembled and modified combustion chamber is 2.2 cm, the outer diameter 4.2 cm and the overall height is 13.0 cm.

Fig. 7. The tested prototype of the combustion chamber
