Abstract
KEYWORDS:
engine, sound power, test bench, spectrum, pass-by noise
ABSTRACT:
The pass-by noise represents a critical parameter in the evaluation of vehicle quality especially nowadays when urban noise becomes a real annoyance and the environmental legislation becomes more stringent. In order to comply with the severe limits imposed by ECE-ONU 51 Regulation, amendment 02 limits for truck noise, the vehicle and engine manufacturers may perform accurate engine noise measurement.
The paper has as main objective a detailed engine noise analysis (amplitude and frequency) in order to indicate the most recommended methods for noise abatement. The investigated engine was 1035L6-DTI (260HP) manufactured at ROMAN Engine Company and the test measurements were performed at Road Vehicle Institute (INAR) on engine test bench.
The test procedure intended to determine the acoustical engine characteristics in different operation modes, as a function of speed and load, as well as the engine noise partition on sources: mechanical noise, combustion noise, fan noise.
There were also simulated the influence of several noise shields using the partial enclosure made of phono-absorbent materials.
The drawn conclusions were very useful and helpful to define the future strategy for noise abatement. The most important findings were the high contribution of mechanical noise in the overall noise, relatively high contribution of fan noise and the confirmation of noise shield efficiency.