Bending-Torsion Flutter Calculations Modified by Subsonic Compressibility Corrections
Abstract
A number of calculations of bending-torsion wing flutter are made at two Mach numbers, M = 0 (incompressible case) and M = 0.7, and the results are compared. The air forces employed for the case of M = 0.7 are based on Frazer's recalculation of Possio's results, which are derived on the assumption of small disturbances to the main flow. For ordinary wings of normal density and of low bending frequency in comparison with torsion frequency, the compressibility correction to the flutter speed appears to be of the order of a few percent; whereas, the correction to the flutter speed for high-density wing sections, such as propeller sections, and to the wing-divergence speed in general may be based on a rule using the (1 - M squared) sup 1/4 factor and, for M =0.7, represents a decrease of the order of 17 percent.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1946
- Accession Number
- ADA801345
Entities
People
- I. E. Garrick
Organizations
- National Advisory Committee for Aeronautics