Design of Fluidic Injector for Supersonic Jet Manipulation

A Mach 2.0 round jet at design and off-design condition is experimentally manipulated using two steady radial injectors to investigate the effect of fluidic injection on jet mixing. Anew scaling law for L-c(*), the supersonic core length of manipulated supersonic free jets, is found as L-c(*) = f(1) (root mrn/[gamma M(j)(2)p(e)/p(a)]), where L-c(*) is normalized by the nozzle throat diameter D-th,gamma is the specific heats ratio, M-j is the ideally expanded jet Mach number, MRN is the momentum ratio of the individual injector jet to the main jet, and p(e)/p(a) is the expansion ratio of the main jet. The discussion pertaining to the scaling law provides an important insight into the choice of diameter ratio d/D for efficient jet manipulation, where d and D are the injector and nozzle exit diameters, respectively. Such insight can yield valuable information on the practical usability of fluidic injectors for the full-scale applications. It is also documented that fluidic injectors can provide an effective flow control mechanism for jet mixing applications in comparison to the elliptic jet.

Automated summary

This experiment investigates the effect of fluidic injection on the mixing of a Mach 2.0 round jet and proposes a new scaling law for efficient jet manipulation. The results demonstrate that fluidic injectors provide an effective flow control mechanism for jet mixing applications compared to the elliptic jet.