EXPERIMENTAL AND CFD ANALYSIS OF CO-AXIAL JET

Abstract

Jet flows are encountered in many practical applications such as jet engines, gas burners, rockets.
To achieve higher spreading rates and to reduce the level of noise, different methods are
employed for jet flow control, such as optimizing the shape or using acoustic liners. In this
paper, the Circular and non-circular co-axial jets are compared by using flow characteristics. The
non-circular shape in this study is hexagonal and cruciform. The circular and non-circular coaxial
jets was made and fitted with a blower setup. The flow field characteristics such as the
pressure distribution and the velocity distribution of the circular and non-circular co-axial jets
were measured using a manometer and pitot tube, respectively. Decay of the jet was investigated
at different axial locations quantitatively by measuring pressure in the jet field. The result of the
study was validated with the help of CFD analysis using Fluent software. The Reynolds stress
mathematical model is usedas governing equations for computation. It is observed that noncircular
co-axial jets decay at a faster rate, and has low velocity distribution and pressure
distribution compared to the circular co-axial jet. It is concluded that circular co-axial jets exhibit
optimum flow characteristics compared to the non-circular co-axial jets.