Jet/Intake Interference in Short Take off, Vertical Landing Aircraft

An experimental programmewas conducted to investigate the aerodynamic interference effects between thejetand intake-induced e ows and the lifting surfaces of a generic jet-lift short take-off and vertical landing aircraft in transitional e ight, out of ground effect. The tests were carried out in an open-jet wind tunnel, and the model was equipped with a single, variable position, vectored lift-jet and powered intakes. Static pressure measurements were made on thewing and intakelips from which airloadswere inferred. Theeffect ofjet to intakemass e owratio on jet/intake aerodynamic interactions was investigated. The experiments conclude that a mutual interference exists between the jet and intake e ows, which generates nonlinearly additive loads on the airframe. The combined jet- and intake-induced interference on the wing increased with increasing jet to intake mass e ow ratio. Ignoring jet/intake interference effects gave a consistently lower overall wing root lift loss, which was equivalent to up to 0.75 deg of incidence. Nomenclature Ai = throat area of one intake [0.002], m 2 Cl = sectional lift coefe cient, fl=q1cg Cni = intake normal force coefe cient,