An Engineering Method for Estimating the Induced Lift on V/STOL Aircraft Hovering in and Out of Ground Effect

摘要

An examination and correlation of available data has shown that two different methods must be used to estimate the jet induced lift on Fan and Jet V/STOL aircraft in hovering flight. The Basic Method developed in this study is used for configurations with widely spaced jets, and the h' Method is used for configurations with closely spaced jets. The methods account for the effects of jet arrangement, configuration planform, wing height, body contour and Lift Improvement Devices (LIDs) but are limited to configurations with essentially vertical, circular jets of equal size and thrust. Suggestions for further work to evaluate and refine the methods are included. (Author)