A Method for Predicting the Upwash Angles Induced at the Propeller Plane of a Combination of Bodies With an Unswept Wing
Abstract
A method has been developed for predicting the upwash angles induced at the horizontal center line of the propeller disk of the twin engine airplane considered in NACA TN 2192, 1950. The method treats each component separately and includes approximations for the interference effects of the other components. Lifting-line theory was used to determine the wing-induced upwash angles. The theory used for the nacelle is an extension of the airship theory of NACA TM 574, 1930. The fuselage-induced upwash angles were determined by means of a solution for the transverse flow about an infinite elliptic cylinder. The boundary conditions of the airship theory used to predict the upwash angles due to the nacelle of the airplane were not strictly satisfied. Therefore, a comparison was made of predicted and measured upwash angles for an isolated nacelle which approximated in shape that of the airplane of NACA TM 2192. The comparison of the computed values of upwash angle with the measured values showed satisfactory agreement. Comparison of the computed and measured total upwash angles showed that the method satisfactorily accounted for the upwash angles induced by the airplane. Although the method was developed for a specific airplane, the method should be applicable to similar airplanes; the conditions of similarity are defined In the report. Modifications to the method are suggested which, it is believed, would make it applicable to certain dissimilar airplanes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1951
- Accession Number
- ADA380453
Entities
People
- Paul F. Yaggy
Organizations
- National Aeronautics and Space Administration