Flow field and acoustics characteristics of elliptical jet

Abstract

PurposeThe purpose of this paper is to present the results of mixing promotion and screech frequency of controlled elliptical supersonic jet.Design/methodology/approachFlow field characteristics of low-aspect-ratio elliptical jets are examined at over-expanded, under-expanded and correctly expanded conditions. The tabs are placed at elliptical jet exit along the major and minor axes.FindingsThe results show that the mixing done by the minor axis is superior to the tabs along major axis. At all pressure ratios, the content of jet noise and the frequency are high for the tabs along the major axis because of increase in the amplitude of screech frequency. Further the tabs along minor axis show a dominance of large-scale vertical structures. In under-expanded conditions, the shock cell shows the rapid change because of the presence of tabs. The tabs along minor axis are making the shock weaker, hence no evidence of axis switching.Practical implicationsTo achieve the greater performance of jet, the authors need to reduce the potential core length of the issuing jet. This can be achieved by implementing different types of tabs at the exit of the nozzle.Originality/valueThe present paper represents the flow of controlled jet using inverted triangular tabs. By achieving the controlled jet flow, the performance of propulsion systems can be improved. This can be used in systems such as combustion chamber, missile’s noise reduction and thrust vector control.