Autori: PODEVIN P., DESCOMBES G., HARA V., CLENCI A.

Editorial: Proceedings of the EAEC Automotive Congress, Belgrade, 2005.

Rezumat:

When talking about diesel engine, it cannot be considered as a true competitor of the gasoline engine without the turbocharging. The most obvious drawback of the engine-turbocharger assembly is the operation of these two machines with highly different laws. This calls for a tuning of their characteristics.
Running at low speeds, which is often encountered in automotive applications, is generally not an optimum range for the turbocharger. Moreover, in this area, the compressor map is not given by the turbocharger’s manufacturer. So, a better knowledge of turbocharger characteristics at low speeds is needed to obtain the improvement of the engine running.
In order to perform this study, a special torquemeter has been fitted in our standard test bench, affording measurements from 30000 rpm to 120000 rpm. The experimental results, which will be presented in this paper, show the combined effect of the lubricating oil temperature and pressure on power demand of the compressor and on oil flow rate. On the basis of these results and on complementary investigation, a better evaluation of compressor efficiency and mechanical losses is given.

Cuvinte cheie: turbocharging, torquemeter, isentropic efficiency, mechanical efficiency, friction losses