Abstract
KEYWORDS:
turbocharging, turbo-lag, friction losses, mechanical efficiency, torquemeter
ABSTRACT:
Often a turbocharger is led to run at low speeds. A better knowledge of turbocharger characteristics at low speeds is needed in order to improve the engine running in this area. As regard friction losses at the turbocharger's shaft, although these are generally small, they have a greater importance in this case of lower speeds.
So, in order to have more information on the mechanical efficiency of the turbocharger, special torquemeter has been fitted in our test bench, affording a speed limit up to 20000 rpm. This device allows the power measurement on the turbocharger's shaft. Applying the first law of thermodynamics, power given to the airflow is calculated and then power losses in the turbocharger's bearings are deducted. This paper presents the first experimentation conducted on the test bench and comments on the results obtained.