Research Projects

The permissible noise level of human ear goes up to 85dBA, beyond which the noise is likely to damage hearing. However noise from the jet, varies from 120dBA to 140dBA. Jet noise in such ranges leads to a temporary ear impairment of the airport personnel and to the people travelling in the aircraft. Hence, aviation engineers and researchers are focusing on how best the noise levels can be reduced and in-turn to increase the jet mixing characteristics of the exhaust jet. This project aims to study the double chevron nozzle configuration with core nozzle and bypass duct focusing on the acoustics benefits due to control via chevron. The influence of chevron design such as, thin and thick lipped chevron, and their penetration angle on jet mixing and jet acoustic characteristics will be studied numerically and experimentally for the jet exit Mach number of 0.6, 0.8 and 1.0. The Pitot pressure and hot wire measurements, along with flow field measurements using PIV, will be analysed in detail and compared with those in the absence of chevron to gain valuable insight into flow physics and jet mixing mechanisms under control. Further, the acoustic characteristics will be studied using the microphone for the specified Mach number and chevron configuration at polar angles ranging from 30 degrees to 150 degrees.