Vorticity and circulation aspects of twin jets in cross-flow for an oblique nozzle arrangement

The 'jet in cross-flow' (JICF) phenomenon, in which a single jet issues normally into a cross-flow through a circular nozzle, is an aspect of many aerodynamic applications and is related to the effectiveness of both propulsion and control systems. In many instances, such applications involve two or more jets that may interact with each other as they develop in the downstream direction. By considering an oblique nozzle ground arrangement, the present experimental work extends the previous results that the authors have obtained for 'twin JICF' (TJICF) concerning two geometrically symmetric TJICF arrangements, namely tandem and side-by-side nozzle configurations. The work concentrates on the vorticity distribution and overall circulation associated with the dominant vortical structure of the TJICF, rather similar to that of the well-known contrarotating vortex pair of the single JICF.