Numerical simulation of dual-jet system in cross flow

Numerical simulations have been carried out for a dual-jet exhaust system issuing perpendicularly into a cross flow. The jets are of equal diameter, and the distance between the jets is four times the jet diameter, with effective velocity ratio of 5 for each jet. Visual evidence of the complex flow field developed is presented. The presence of a jet inside the region of influence of another jet is seen to produce coherent flow structures different from the structures seen in the single jet in cross flow configuration. It is observed that neither the jet center planes nor the plane mid-way between the jets act as symmetry planes. Hence, modeling multiple jets with the jet centre plane as a symmetry boundary may not be consistent with the physics involved. Results show that the dual-jet system does not penetrate into the cross flow as much as a single jet does. This behavior will significantly affect performance of multiple jet systems used for improved mixing. Key Words: jets in cross flow, multiple jets, mixing, dual-jet system, coherent flow structures.