Field of Flow about a Jet and Effect of Jets on Stability of Jet-propelled Airplanes

Summary: The flow inclination induced outside cold and hot propulsive jets by the turbulent spreading has been derived. Certain simplifying assumptions were employed and the region near the orifice was not treated. The effect of jet temperature on the flow inclination was found to be small when the thrust coefficient is used as the criterion for similitude. The deflection of a jet due to angle of attack has been derived and found to be appreciable but small for normal flight conditions with small normal accelerations. The average jet-induced downwash over a tail plane has been obtained in terms of the geometry of the jet-tail configuration. These results have been applied to the estimation of the effect of the jets on the static longitudinal stability and trim of jet-propelled airplanes.