Effects of load on noise emission level generated by diesel engine including biodiesel application

This study uses pure diesel (D100) and palm oil methyl ester (POME) to investigate the relation of engine load to the noise level in a single-cylinder direct-injection diesel engine. The D100 and B20 of POME are tested using constant engine speed under different engine loads. The Sound Power Level (SPL) analysis is employed to identify the noise rating where the level is assessed by the grid set on the noise source. Varying the engine load into five levels, the results indicated a linear relationship notable as the increment in engine load owes to the increment of the noise level in the engine. A consistent trend is also noticeable, where the gradual increment of noise level can be reported regardless of the component assessed. Considering the biodiesel usage, it is proven that in most parameters, the B20 blend is better than the D100, which reduces approximately 3 dB(A) or more. The highest SPL can be reported at 92.705 dB(A) in the engine mounting with pure diesel usage, while the lowest SPL, 80.581 dB(A), is obtained in the upper intake pipe with the biodiesel usage. In summary, it is evident that the engine load is one of the crucial parameters that affect the generation of SPL; attractively, with the superior ability of biodiesel, a reduction can be expected.