Jet Efflux Characteristics and their Influence on STOVL Aircraft Propulsion-Induced Effects

962250

11/18/1996

Event
SAE International Powered Lift Conference and Exposition
Authors Abstract
Content
The direct relation between subcriticai jet efflux characteristics and propulsion induced changes in STOVL aircraft forces and moments is described in this paper. Subcriticai jets may have core lengths which range up to 6 diameters. The shorter core length jets tend to entrain ambient air more rapidly, inducing larger hover lift losses, and decay more rapidly, reducing adverse ground erosion. In transition flight, shorter core length jets show a decrease in the lift loss. Supercritical pressure ratio jets are also described; they tend to have a longer, higher pressure core. For both subcriticai and supercritical pressure ratio jets, the dynamic pressure decay is similar. In ground effect the supercritical jet induces an oscillating pressure distribution on the ground with reflected shocks and expansions which can increase ground erosion and at low ground heights cause non-monotonic lift loss variations. The limited experimental data available suggest that there is a need for a systematic investigation to more adequately relate supercritical jet decay to hover and transition flight induced aero/propulsion effects.
Meta TagsDetails
DOI
https://doi.org/10.4271/962250
Pages
8
Citation
Margason, R., Arledge, T., Wardwell, D., Hange, C. et al., "Jet Efflux Characteristics and their Influence on STOVL Aircraft Propulsion-Induced Effects," SAE Technical Paper 962250, 1996, https://doi.org/10.4271/962250.
Additional Details
Publisher
Published
Nov 18, 1996
Product Code
962250
Content Type
Technical Paper
Language
English