PIV Studies on the Effect of the Number of Lobes in a Supersonic ESTS Lobed Nozzle
ESTS lobed nozzle is found to be efficient in supersonic jet mixing applications. In this study, the influence of a number of lobes on the aspects of mixing is probed using the 2D-PIV measurements. From the analysis of the obtained 2D velocity field, the kinematics of the lobed nozzle is reported for the first time experimentally. Centerline velocity decay, turbulence intensity, and mass efflux are calculated to compare the influence of a different number of lobes in the lobed nozzle. The conical nozzle is used as the base nozzle for comparison. It is observed that the three-lobed nozzle is efficient in terms of mixing and jet spread. Especially an increment of 70% in the jet spread is observed for three-lobed nozzle. The primary reason for the observed enhancement is due to the higher penetration of the lobe tip into the core flow (by 30% compared with the six-lobed nozzle) which produces larger-scale streamwise vortices than the other cases under consideration.
Ministry of Human Resource Development (MHRD), India; Defence Research and Development Organisation (DRDO), India; and Council for Scientific and Industrial Research (CSIR), India.
- 5.S.K. Karthick et al., J. Indian Inst. Sci. 96, 1 (2016)Google Scholar