Accession Number : ADA266656


Title :   New Vortex Dynamics Methods for Rotor Free Wake Analysis


Descriptive Note : Final rept. 15 May 88-14 May 91,


Corporate Author : DUKE UNIV DURHAM NC


Personal Author(s) : Bliss, Donald B


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a266656.pdf


Report Date : May 1993


Pagination or Media Count : 52


Abstract : This report summarizes recent work on rotorcraft aerodynamics involving novel methods for rotor free wake calculations. A new method called Analytical/Numerical Matching (ANM) was developed. ANM is a hybrid analytical and numerical method that achieves accurate results by combining a low resolution numerical solution with a high resolution analytical solution. Although originally developed for vortex dynamics, ANM has proven to be of a general nature. The application of ANM to the rotor wake problem provides accurate answers with a significant reduction in computation time. The use of ANM introduces the opportunity to develop new solution strategies, including Far-Field Linearization and Periodic Inversion. These methods afford the means to obtain accurate solutions Over the entire flight regime. Work involving applications of ANM has also led to a scheme that represents vortex filament dynamics by a hierarchy of nested problems of varying resolution joined by matching solutions. This approach, called ANM with Pyramiding (ANM/P), has reduced calculation times by more than a factor of twenty in some sample problems.


Descriptors :   *ROTOR BLADES(ROTARY WINGS) , *WAKE , *ROTARY WING AIRCRAFT , *AERODYNAMICS , VELOCITY , COMPUTATIONS , FAR FIELD , TIME , FILAMENTS , ROTORS , MATCHING , PERIODIC VARIATIONS , LOW RESOLUTION , NEAR FIELD , THRUST , AZIMUTH , INVERSION , FLIGHT , HELICOPTERS , HIGH RESOLUTION , DYNAMICS , VORTICES


Subject Categories : Aerodynamics
      Helicopters


Distribution Statement : APPROVED FOR PUBLIC RELEASE