The main objective of this study is to explore the flow structure and its acoustic radiation from a military-style supersonic nozzle with and without chevrons of Md 1.4. Schlieren images were captured for both baseline and chevron nozzles, and these images were processed through MATLAB R2022b to enhance the flow structures. The shock cell length of the Chevron nozzle is 18–21% lower than the base nozzle. In the highly over-expanded case, zero penetration chevrons haven’t provided significant flow changes. Axial vortices induced by the chevron resulted in lobed jet formation, which increased initial mixing near the nozzle exit. Far field acoustic measurements of baseline and chevron nozzles were carried out, and inferences were made. Optimum noise reduction was obtained at the nozzle pressure ratio (NPR) 2.7 (over-expansion), with a maximum SPL reduction of around 4.1 dB at 45°. In an under-expanded case, the expansion of the jet enhances the performance of the chevron. This resulted in maximum noise reduction at NPR 4.2, with a range of reduction of around 4.9 dB (at 45°) and 1.9 dB (at 60°) compared to the baseline nozzle. Thus, Chevron has been able to provide an optimum noise reduction in an imperfectly expanded case with a minimum expected thrust penalty, which can lead to a significant result for practical applications.