Aero Engine Noise Source Analysis And Research Of Suppression Of Jet Noise

Noise is one of the key indicators of the modern design of large civil aircraft, the main sources of noise include civil aircraft airframe noise and engine noise, with the development of modern high bypass ratio engine aircraft, the noise level of the engine has been significantly reduced, but still one of the major sources of noise in large civil aircraft. As the world's requirements of aircraft engine noise become increasingly strict, the control of high bypass ratio turbofan engine noise becomes particularly important. Therefore, for the typical turbofan engine, this paper carried out Aero engine noise source analysis and Research of suppression of jet noise. In terms of noise sources, we analyzed the different parts of the engine noise sources(including turbomachinery noise and combustion noise and jet noise).First, we analyzed the engine turbomachinery noise to understand the mechanism and the type of the noise, and distinguished the main noise and the secondary noise; Second, we analyzed the noise of the engine combustion chamber, because of the complexity of aero-engine combustion noise, we analyzed the mechanism of combustion noise; Finally,we briefly introduced the jet engine noise. In terms of noise suppression, based on the mechanism and characteristics of the noise, we analyzed several noise suppression technologies. First, in the turbomachinery noise, referencing the existing documents, we analyzed four noise reduction technologies, which have the good effects for the noise reduction; Second, because of the harsh environmental conditions and the lack of research in combustion noise reduction, in this paper, we analyzed the combustion chamber of the engine noise factors, hoping to find a method of noise reduction technology; Finally, for the aero-engine jet noise reduction technology, we use the zigzag tail jet technology, we calculated the distribution of its jet noise by Ansys software simulation of an engine model and we get the result of zigzag tail jet noise reduction technology, the result proved that the zigzag tail jet technology could reduce the noise by 4-5 decibels, it is a practical technology for the future engine, in addition, we find the optimized numbers of gears.