Accession Number : AD0782955

Title :   Streamline Calculations Using XYZ Potential Flow Program,

Corporate Author : ARMY AIR MOBILITY RESEARCH AND DEVELOPMENT LAB FORT EUSTIS VA EUSTIS DIRECTORATE

Personal Author(s) : Gillespie,James , Jr

Report Date : MAY 1974

Pagination or Media Count : 23

Abstract : Potential flow and boundary layer calculations have been performed on various helicopter fuselage configurations as part of an overall program to provide an analytical method to predict and subsequently reduce parasite drag. The boundary layer calculation uses the small crossflow assumption and requires a knowledge of the streamline divergence. The present method for calculating streamline divergence is not completely satisfactory. The XYZ potential flow program, developed by the Naval Ship Research and Development Center, appeared to have a more attractive streamline divergence calculation. Streamline divergence calculations using the XYZ program were validated on a cone, a sphere, and the HLH model. In addition, a potential flow calculation, using the XYZ program, was performed on a scale model of the Boeing Vertol Heavy Lift Helicopter (HLH), and the results agreed very well with wind tunnel test data. These results indicate that the XYZ potential flow program can be used to calculate the streamline divergence of advanced Army Helicopter fuselage configurations. (Author)

Descriptors :   *HELICOPTERS, *DRAG REDUCTION, BOUNDARY LAYER, FLUID FLOW, FUSELAGES, FLOW FIELDS, COMPUTER APPLICATIONS

Subject Categories : Aerodynamics
      Helicopters

Distribution Statement : APPROVED FOR PUBLIC RELEASE