Evaluation of Lubricity Fuels by Sound Pressure Analysis in Dynamic Regime Using Fourier Transform
Alexandre Augusto Souza Medeiros1; Aline Cristina Mendes de Farias1; José Josemar de Oliveira Júnior1; Salete Martins Alves1
1 UFRN
doi:10.20906/CPS/COB-2015-1218
Resumo
The lubricity is an important property of diesel and biodiesel fuels because it produces a protecting layer on the metal surface to prevent wear of engine moving parts, such as fuel injectors and pumps. According to ASTM D6079, the HFRR (High Frequency Reciprocating Rig) tribometer is used to characterize the lubricity fuels, considering only wear scar diameter (WSD) on lubricated contact. On the order hand, this information is not sufficient to characterize the tribological behavior of a fuel, others tribological parameters can be analyzed, such as friction coefficient and film formation. Furthermore, there are others non-intrusive parameters that allow evaluate the tribological behavior in a dynamic regime as sound pressure signals. The characterization of these signals can be made by Fourier Transform Analysis. In this context, the present work evaluated the effect of biodiesel addition on the diesel lubricity using sound pressure signals and application of Fourier Transform. HFRR tests were carried out by lubricated steel ball-on-disc contact using different blends (B10, B20) of diesel S50 with soybean biodiesel. A sound pressure sensor attached to the system permitted to obtain the signals during the test. These signals were analyzed by Fourier Transform and their associations with parameters supplied by ASTM D6079. These analyses allowed to capture the small fluctuation of sound pressure signals and it can be associated with the wear evolution during lubricated contact as well as WSD values.
Palavras-chave: lubricity; biodiesel; sound pressure signal; FFT