Accession Number:

ADA574192

Title:

Performance Results from a Test of an S-76 Rotor in the NASA Ames 80- by 120- Foot Wind Tunnel

Descriptive Note:

Conference paper

Corporate Author:

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION MOFFETT FIELD CA AMES RESEARCH CENTER

Personal Author(s):

Report Date:

1993-08-01

Pagination or Media Count:

21.0

Abstract:

A full-scale helicopter rotor test was conducted in the NASA Ames 80- by 120-Foot Wind Tunnel with a four-bladed S-76 rotor system. This wind tunnel test generated a unique and extensive data base covering a wide range of rotor shaft angles-of-attack and thrust conditions from 0 to 100 kt. Hover rotor performance data were compared with calculations based on momentum theory and previously acquired data from other test facilities to evaluate the capabilities of this wind tunnel as a hover facility. Forward flight rotor performance data were compared with the calculations from a comprehensive rotorcraft analysis, CAMRADIJA, to evaluate the analytical modelling in the 0 to 100 kt speed range. Rotor performance data were also compared with previously acquired S-76 full-scale data from a test in the Ames 40- by 80-Foot Wind Tunnel to evaluate similarities and differences between the two facilities. Hover performance data show significant variations depending on the test configuration. Comparisons with theoretical predictions and other test data suggest that hover testing at an outdoor facility in absence of ground effect is required to make a final determination of the absolute accuracy of the hover data acquired in the 80 x 120. CAMRADIJA calculations show good correlation with propulsive force data and a consistent level of overestimation of rotor power throughout the thrust and rotor shaft angle-of-attack envelope for a velocity range of 40 to 100 kt below 40 kt CAMRADIJA power calculations diverge from the data. A comparison of the 80 x 120 data with data from a previous 40 x 80 wind tunnel test for 60 to 100 kt velocity range shows good correlation with rotor power and propulsive force data, except at the higher rotor shaft angles where there are some differences in rotor power. Results from the two S-76 wind tunnel tests suggest that the wind tunnel wall cor

Subject Categories:

  • Helicopters
  • Test Facilities, Equipment and Methods

Distribution Statement:

APPROVED FOR PUBLIC RELEASE