Accession Number:

ADA109687

Title:

A Surface Singularity Method for Rotors in Hover or Climb.

Descriptive Note:

Final rept. 29 Mar 79-30 Sep 81,

Corporate Author:

ANALYTICAL METHODS INC REDMOND WA

Personal Author(s):

Report Date:

1981-12-01

Pagination or Media Count:

142.0

Abstract:

A surface singularity potential flow code, ROTAIR, has been assembled for the calculation of detailed surface pressures on rotors in hover or climb. This method is basically a marriage of two codes the fixed-wing surface singularity doublet code and the rotor lifing-surface code. The program includes a tip vortex separation model. Also, the rotor tip surface is panelled so that pressures are calculated right around the tip-edge surface. Preliminary calculations have verified the capabilities of the program for computing blade surface properties in the presence of a close-vortex passage. Additionally, calculated pressure distributions compare favorably with experimental data for a low aspect ratio two-bladed rotor, and the calculated circulation distribution is consistent with that computed earlier with the lifting-surface code. Finally, the newly developed far-wake doublet model promises to keep computing efforts practical. Author

Subject Categories:

  • Helicopters
  • Numerical Mathematics
  • Computer Programming and Software
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE