Effect of Perforated Tab on Noise Mitigation of a Mach 1.8 Jet

Abstract

This experimental study examines the impact of supersonic converging-diverging nozzle flows on improving noise reduction and fuel efficiency in supersonic and hypersonic aircraft, thereby contributing to sustainable advancements in aerospace technology. A Mach 1.8 nozzle equipped with a perforated 30° angled tab was used for the current experiment to study the acoustic and mixing characteristics of the jet. It is anticipated that such a configuration would lead to improved mixing and reduced noise levels. To validate these expectations, pitot pressure experiments were conducted to examine jet decay and spreading characteristics. Acoustic measurements were conducted at a semianechoic jet facility to examine the noise level. By comparing the performance of the jets with and without the perforated tab, our findings revealed a significant reduction in the potential core length of the controlled jet, which was 65.4% shorter than that of the baseline jet. Moreover, the introduction of the perforated tab resulted in a maximum overall sound pressure level reduction of up to 6 dB. These results underscore the efficiency of perforated tabs in enhancing jet mixing and diminishing noise, thereby offering promising avenues for the design of environmentally friendly supersonic nozzles and offering promising avenues for the design of supersonic combustor nozzles with improved overall performance.