Coupling of Underexpanded Twin-Jets

Aircraft jet engines produce thrust by exhausting a jet of high velocity gas. The jet produces a large portion of the overall aircraft noise once it leaves the engine and interacts with the surrounding air. This noise is enhanced if two jets (or engines) are placed close together. The two closely spaced exhausting jets interact, producing noise that is greater than the sum of two isolated jets. This work examines the coupling interaction and identifies the ways that the jets can couple together.