Experimental and Numerical Analysis of Flow Acoustics Over Different Co-annular Nozzle Shapes

Co-annular or coaxial nozzles are normally used in the aircraft exhaust nozzles for various applications such as noise reduction, mixing enhancement, thrust vectoring, infrared signatures, etc. This paper investigates the flow acoustics of three different co-annular nozzle geometries such as base circular nozzle, circle-chevron and chevron-circle nozzle with the various parameters such as acoustic power level, sound pressure level and velocity magnitude. The computational analysis has been done with the three nozzles for a pressure of 60 psi at the inlet and experimental analysis with various pressures such as 70, 80, and 90 psi. Based on the investigations it is observed that the co-annular nozzle circle-chevron nozzle shows better mixing enhancement and noise reduction compared to other nozzle shapes.