Modelling and CFD Acoustic Analysis of Different Chevron Nozzles Using ANSYS for Jet Noise Reduction

Jet engine noise, particularly the pervasive jet noise generated during fluid expulsion from the nozzle, presents a significant environmental and community nuisance, especially for populations residing near airports, with peak intensity occurring during take-off. In response to stringent noise regulations, the aviation industry is actively pursuing advanced noise reduction strategies. One highly effective solution being implemented in commercial aircraft is the chevron nozzle. This innovative design operates by introducing small disturbances near the engine's exit, which are hypothesized to disrupt large-scale turbulent mixing. This disruption, in turn, effectively reduces the dominant low-frequency jet mixing noise stemming from large- scale cellular vortices.This research specifically investigates the acoustic performance of N8 and N16 chevron nozzle configurations, directly comparable to those utilized in the Bombardier CRJ900. Our primary objective is to systematically understand the influence of various geometric design parameters on the chevron nozzle's ability to attenuate jet noise from turbofan engines. To achieve this, 3D models of the N8 and N16 designs were meticulously created using SolidWorks, and their acoustic characteristics were subsequently simulated and analyzed through ANSYS-Fluent. This rigorous computational fluid dynamics (CFD) approach allows for the precise evaluation of how parameters such as the number of chevrons, their penetration depth, and their angle impact the overall noise signature. Our comprehensive acoustic analysis unequivocally demonstrates that the strategic implementation of chevrons is a highly effective method for achieving significant noise suppression in jet engine exhaust. The findings from this detailed comparative analysis are crucial for identifying optimal design elements that contribute most effectively to noise reduction, ultimately contributing to the development of quieter aircraft essential for both environmental sustainability and enhanced community acceptance